Procalcitonin Does Not Discriminate Infection from Inflammation after Allogeneic Bone Marrow Transplantation

Procalcitonin (PCT) is an early marker of bacterial infection but little is known about its value in neutropenic allogeneic bone marrow transplant (BMT) recipients. We collected plasma from 12 recipients of T-cell-depleted HLA-matched related BMT recipients who had been treated preemptively with meropenem from the day after BMT for at least 15 days. PCT and C-reactive protein (CRP) concentrations were determined on BMT days 1, 5, 8, 12, and 15, and their relationship to inflammatory events (IE), including mucositis, microbiologically and clinically defined infections, acute graft-versus-host disease (GVDH), and unexplained fever, was then determined. The PCT concentrations were all low and never exceeded 4 μg/liter, unlike CRP concentrations, which spanned the full range up to 350 mg/liter. All patients had mucositis, and there was no significant difference between PCT concentrations associated with mucositis alone and those associated with an additional IE on BMT days 1 to 12. However, on BMT day 15, the mean concentrations of PCT were 0.37 ± 0.05 μg/liter for the 10 patients that had an additional IE, compared with 0.11 ± 0.03 μg/liter for the 2 patients with mucositis only (P = 0.012), and GVHD rather than infection was involved in six cases. PCT was also not a sensitive marker of gram-positive bacteremia or pulmonary aspergillosis. Thus, PCT is of little value in discriminating infections from other inflammatory complications that occur following allogeneic BMT.     

Human cytomegalovirus immediate-early mRNA detection by nucleic acid sequence-based amplification as a new parameter for preemptive therapy in bone marrow transplant recipients

Human cytomegalovirus (HCMV) infection was monitored retrospectively by qualitative determination of immediate-early (IE) mRNA by nucleic acid sequence-based amplification (NASBA) in a series of 51 bone marrow transplant (BMT) recipients. The qualitative results for IE mRNA obtained by NASBA were compared with those obtained by prospective quantitation of HCMV viremia and antigenemia and retrospective quantitation of DNA in blood (DNAemia) by PCR as well as by qualitative determination of late pp67 mRNA by NASBA. On the whole, of the 39 HCMV-positive patients (all asymptomatic), HCMV was detected in 14 (35.9%) by quantitation of viremia, 15 (38.5%) by detection of pp67 mRNA by NASBA, 32 (82.1%) by quantitation of DNAemia, and 33 (84.6%) by quantitation of antigenemia, while HCMV was detected in 38 (97.4%) patients by detection of IE mRNA by NASBA. In the immunocompetent host, IE mRNA was not detected by NASBA in 100 blood donors or during reactivated infections in 30 breast-feeding mothers. Likewise, NASBA did not detect IE mRNA in 56 solid-organ transplant recipients in the first 21 days after transplantation. By using NASBA for detection of IE mRNA as the reference standard for detection of HCMV infection in blood samples, the diagnostic sensitivities were 67.7% for quantitation of DNAemia, 59.0% for quantitation of antigenemia, 18.3% for detection of pp67 mRNA by NASBA, and 16.0% for quantitation of viremia. Specificities and negative and positive predictive values were >90.0, >70.0, and >80.0%, respectively, for all four assays. The mean times to first HCMV detection after bone marrow transplantation were 37.7 +/- 15.4 days for detection of IE mRNA by NASBA, 39.6 +/- 15.6 days for quantitation of antigenemia, 40.9 +/- 15.2 days for quantitation of DNAemia, and 43.7 +/- 16.3 or 43.7 +/- 17.5 days for quantitation of viremia and detection of pp67 mRNA by NASBA, respectively. On the whole, 31 BMT recipients received preemptive therapy by using confirmed antigenemia positivity as a cutoff, while 35 patients could have been treated by using NASBA positivity as a cutoff and 31 could have been treated by using quantitation of DNAemia as a cutoff. In single patients, IE mRNA was detected in every episode of active HCMV infection, mostly preceding and sometimes accompanying antigenemia and DNAemia, whereas pp67 mRNA was detected only concomitantly with the highest peaks of infection. HCMV IE mRNA detection may represent a useful parameter for initiation of preemptive therapy in BMT recipients.     

Photochemical treatment of donor lymphocytes inhibited their ability to facilitate donor engraftment or increase donor chimerism after nonmyeloablative conditioning or establishment of mixed chimerism.

Donor T-cells can provide a graft-versus-leukemia effect and help to promote donor engraftment after allogeneic BMT; however, these benefits can be outweighed by the ability of the cells to induce life-threatening GVHD. Photochemical treatment (PCT) of T-cells with S-59 psoralen and long-wavelength UV-A light can inhibit their proliferative capacity and significantly decrease their ability to induce acute GVHD after allogeneic BMT. PCT donor T-cells have been shown to facilitate donor engraftment in a myeloablative BMT model. In this study, we examined whether donor T-cells subjected to PCT ex vivo could retain the ability to facilitate engraftment or increase donor chimerism after nonmyeloablative BMT or after establishment of mixed hematopoietic chimerism. In a transplantation model in which mice were conditioned for BMT with sublethal (600 cGy) TBI, an infusion of PCT donor T-cells was unable to facilitate engraftment of donor BM. A BMT model was used in which a mixture of allogeneic and syngeneic marrow cells was infused into lethally irradiated recipients for establishment of mixed hematopoietic chimerism. The goal was to determine whether PCT donor splenocytes could increase levels of donor chimerism. Recipients of splenocytes treated with UV-A light only (no S-59 psoralen) and given at the time of BMT or in a donor lymphocyte infusion (DLI) had significantly higher levels of donor chimerism than did recipients of BM only. Although PCT donor splenocytes given at the time of BMT modestly increased donor chimerism, PCT donor splenocytes given in a DLI did not increase donor chimerism. A nonmyeloablative BMT model was employed for determining whether DLI given relatively late after BMT could increase donor chimerism. Recipient mice were conditioned for BMT with a combination of low-dose TBI (50 or 100 cGy) and anti-CD154 (anti-CD40L) monoclonal antibody for achievement of low levels of mixed chimerism. When control mixed chimeras were given a DLI 71 days after BMT, donor chimerism was significantly increased. In contrast, PCT of the donor cells eliminated the ability of the cells to increase donor chimerism after infusion. Together results from these 3 distinct BMT models indicate that PCT of donor T-cells significantly inhibited the ability of the cells to facilitate donor engraftment after nonmyeloablative BMT or to increase donor chimerism in mixed hematopoietic chimeras when the cells were administered in a DLI.     

Defective anticarbohydrate antibody responses to naturally occurring bacteria following bone marrow transplantation.

The long-term recipients of allogeneic bone marrow transplantation (BMT) are at an increased risk of death due to bacterial infections. We evaluated the anticarbohydrate antibody responses of BMT recipients to a naturally occurring bacterial carbohydrate, polyribose phosphate (PRP). The recipients of autologous BMT achieved protective anti-PRP levels (>100 ng/mL) by 3 years after transplantation, with a pattern consistent with a recapitulation of the ontogeny of anticarbohydrate antibody responses. None of the six recipients of unrelated BMT who were off immunosuppressive therapy had protective anti-PRP levels, though their response to a protein antigen (tetanus toxoid) was normal. Of 48 recipients of histocompatible BMT, 22 (46%) had protective anti-PRP antibody levels, whereas 13 (27%) recipients who were >3 years post-BMT did not have protective levels. Therefore, all unrelated recipients and a significant proportion of histocompatible recipients without clinical graft-vs.-host disease had persistent and prolonged defects in their capacity to produce antibodies to naturally occurring bacterial carbohydrate antigens. These results suggest that allogeneic BMT recipients should be longitudinally evaluated for their anticarbohydrate antibody responses and that patients with defective antibody responses should receive prophylactic antibiotics or replacement immunoglobulin therapy or both to reduce their risk of late bacterial infections.     

Serum procalcitonin concentrations in transplant patients with acute rejection and bacterial infections.

Procalcitonin (PCT) represents a new marker of systemic inflammatory reactions of the body to infections. PCT is selectively induced by severe bacterial infections leading to sepsis or multiorgan dysfunction syndrome. The aim of our study was to test PCT as a postoperative infection marker in heart and kidney transplant patients compared with healthy subjects and patients with localized lung-inflammatory processes without a manifest systemic response. PCT concentrations were measured by an immunoluminometric assay (ILMA) in a total of 419 serum samples. Normal serum levels were in the range of 0.08-0.6 ng/ml. Operative trauma associated with heart (not kidney) transplantation induced a transient increase in PCT levels to 7-10 ng/ml with a decline to normal levels within 2-3 days in most patients. Severe bacterial infections dramatically augmented serum PCT concentrations reaching values of 46-297 ng/ml in the most critical periods. Good response to antibiotic therapy was associated with a decline in serum PCT concentrations. Acute rejection or cytomegalovirus infections did not significantly increase the serum PCT levels. Localized pulmonary infections showed either no, or only a limited increase, in the serum PCT levels (max. 7 ng/ml). We conclude from our data that PCT can be used as a sensitive marker to differentiate systemic bacterial infections from other complications in organ transplantation.     

Assay for determination of the serum procalcitonin level: biochemical and clinical evaluation

In patients with inflammatory conditions such as infection, cytokines induce the production of C-reactive protein(CRP) and serum amyloid A protein(SAA) in hepatic cells. It has been reported that upon viral infection, the serum SAA level increases by a greater degree than the serum CRP level. Procalcitonin (PCT), the precursor of calcitonin, is a new type of inflammatory marker that is specifically induced by bacterial infection, sepsis and lethal multiple organ failure, but not by viral infection, autoimmune diseases, tumors or surgical stress. To evaluate the immunoluminometric assay(LUMI test PCT; Brahms Diagnostics, Berlin, Germany) procedure for determining the PCT level and to study the clinical significance of the serum PCT level, we determined the serum levels of PCT, CRP and SAA in patients with various inflammatory diseases and normal subjects. The serum PCT level in the normal subjects was < 0.3 ng/ml. Among the patients with inflammatory disease who had a high CRP level(CRP > 20000 micrograms/dl), the PCT level was elevated only in those patients with severe bacterial infection. These results suggest that determining the PCT level may be useful in the differential diagnosis of severe bacterial infection. The patients who had a low CRP level(CRP < 150 micrograms/dl), had a PCT level within the normal range. The patients with autoimmune disease, viral infection, and fungal infection did not have an elevated PCT level.     

HSV excretion after bone marrow transplantation: a 4-year survey

BACKGROUND: Herpes simplex virus (HSV) oral excretions are common after bone marrow transplantation (BMT). OBJECTIVE: We report a 4-year systematic survey of HSV excretions in an adult population who underwent BMT (289 transplantations). STUDY DESIGN: Patients received either intravenous ACV treatment when mucositis occurred or systematic intravenous ACV prophylaxis from initiation of the BMT conditioning until the end of aplasia. All patients were followed up for HSV excretions. RESULTS: Twenty-eight patients (9.7%) excreted HSV. The occurrence of HSV excretions was similar in both allogeneic and autologous transplant patients. The incidence was significantly lower when ACV was systematically used after transplantation (2.5%) compared to when ACV was implemented for mucositis (12%). ACV-resistant HSV was detected in three patients who received allogeneic transplantation, representing 27% of allogeneic recipients excreting HSV. CONCLUSION: HSV infection prophylaxis with high dose of intravenous ACV resulted in a decreased incidence of HSV excretion. Nevertheless, the risk of emergence of ACV resistance, especially among allogeneic transplant patients, appears to be identical whatever the route and dose of ACV prophylaxis.     

A comparison of related donor peripheral blood and bone marrow transplants: importance of late-onset chronic graft-versus-host disease and infections.

Peripheral blood hematopoietic stem cell (PBSC) transplants have been shown to result in more rapid engraftment than standard bone marrow transplants (BMTs). Little comparative data exist regarding complications in patients receiving transplants using these stem cell sources. In our study, 97 adults with advanced hematologic malignancies who received allogeneic PBSC transplants were compared with 97 adults who received allogeneic BMTs using identical preparative regimens and support parameters. The incidence of systemic infections and other major complications occurring within the first year after transplantation were calculated in both groups. Proportional hazard analysis was used to examine risk factors for death and complications in both groups. Patients receiving PBSC transplants had more rapid neutrophil (17 days versus 24 days; P <.001) and platelet engraftment (28 days versus 47 days; P <.001) than BMT recipients. The survival rate at 2 years was 38% in PBSC transplant recipients and 28% in marrow recipients (P =.08). There was no difference in rates of grade II to IV acute graft-versus-host disease (GVHD) between groups (PBSC 46%, BMT 51%; P =.3). PBSC transplant recipients were more likely to develop chronic GVHD after 180 days (hazard ratio 2.2; P =.05). Accompanying this "late-onset chronic GVHD," a pattern of more frequent late systemic fungal and cytomegalovirus infections was observed in PBSC transplant recipients. In conclusion, although PBSC transplant recipients engraft more quickly than BMT recipients and have somewhat better 2-year survival rates, they develop more frequent late-onset chronic GVHD and may have more late fungal and cytomegalovirus infections than marrow recipients. Further studies must examine this late-onset chronic GVHD and better characterize immune reconstitution in PBSC transplant recipients to understand their effects on patient recovery.     

Pharmacokinetics and pharmacodynamics of anti-thymocyte globulin in recipients of partially HLA-matched blood hematopoietic progenitor cell transplantation.

Polyclonal anti-thymocyte globulin (ATG) administered before allogeneic blood hematopoietic progenitor cell transplantation reduces the risks of graft rejection and graft-versus-host disease, but may delay posttransplant immune reconstitution caused by delayed clearance of ATG from the blood. We studied graft-versus-host disease, infections, and the kinetics of immune reconstitution in 28 patients with very poor-risk hematologic malignancies who received lymphocyte-depleted, CD34(+) cell-enriched hematopoietic progenitor cell grafts from partially HLA-matched related donors (PMRD). The incidence of these clinical events was correlated with blood ATG levels in 19 transplant recipients who received rabbit ATG (r-ATG, thymoglobulin) during conditioning. Total r-ATG and the fraction of ATG antibodies that bind human cells (active ATG) were measured for up to 45 days posttransplantation using enzyme-linked immunosorbent assay and flow cytometry assays. Three patients received equine ATG (e-ATG; total dose of 60 mg/kg/day), 3 patients received 10 mg/kg r-ATG, and 22 patients received 6 mg/kg r-ATG during conditioning. All evaluable patients engrafted. Median numbers of blood CD4(+) and CD8(+) T cells at 100 days posttransplantation were 15 and 8 cells/microL, respectively. Acute graft-versus-host disease developed in 3 of 3 recipients of e-ATG and 1 of 25 recipients of r-ATG. Rapid T-cell reconstitution was seen only in younger patients. Overall mortality was 93% (26/28 patients) with poor immune reconstitution contributing to death in 21 of 28 patients. Recipients of 6 mg/kg r-ATG had peak levels of total and active r-ATG of 64+/-20 microg/mL and 9.2+/-5.8 microg/mL, respectively, with clearance of active r-ATG (t(1/2)6 days) to sub-therapeutic levels (<1 microg/mL) by a median of 15 days posttransplantation (range, 8-38 days). Delayed immune reconstitution is likely a consequence of ex vivo and in vivo purging of donor T cells in the graft coupled with inadequate thymic function rather than persistence of active r-ATG in the blood for months posttransplantation.     

Analysis of procalcitonin and CRP concentrations in serum of patients with chronic spontaneous urticaria

Background

Our previous findings showed the importance of analysing the peripheral markers of acute phase response (APR) activation, C-reactive protein (CRP) and IL-6 in the context of urticaria activity and severity. However, these biomarkers do not reliably differentiate between APR to infectious and the disease severity.

Aim

In order to investigate a possible association between the immune-inflammatory activation markers CRP and procalcitonin (PCT).

Methods

Serum PCT and CRP concentrations were measured in patients with CU of varying severity as well as in healthy subjects.

Results

Serum PCT and CRP concentrations were significantly increased in more severe CU patients when compared to healthy controls and mild CU, and within the CU population there was a significant correlation between concentrations of PCT and CRP. Serum PCT concentrations remained within normal ranges in most CU patients and were only slightly elevated in some severe CU cases.

Conclusions

PCT serum concentration may be only slightly elevated in some cases of severe CU. Upregulation of PCT synthesis accompanied by parallel changes in CRP concentration reflects a low-grade systemic inflammatory response in CU. PCT should be considered as a better marker than CRP to distinguish between APR to infection and an active non-specific urticarial inflammation.     

Expression of p75 chain of IL-2 receptor in the early immunological reconstitution after allogeneic bone marrow transplantation.

Expression of p55 and p75 chains of IL-2 receptor (IL-2R) on the surface of both T and natural killer (NK) circulating lymphocytes was investigated in 14 paediatric patients given allogeneic bone marrow transplantation (BMT) from HLA-identical sibling or partially matched family donors. IL-2-induced proliferative and cytotoxic responses were also studied and all analysis was performed within 45 days from transplant. We found that, early after transplant, the percentage of p55+ and of p75+ peripheral blood lymphocytes (PBL) was not significantly different in patients who had received HLA-identical BMT (p55+ 8.04 +/- 4.87%; p75+ 28.27 +/- 18.85%) compared with healthy controls (p55+ 7.26 +/- 6.17%; p75+ 19.42 +/- 10.49%), while recipients of T cell-depleted marrow included a remarkably high percentage (76-90%) of p75+ PBL, which were mostly CD3- and co-expressed CD56 molecule. Comparable values of p55+ lymphocytes were observed in all patients and controls. However, in contrast to the other two groups, in recipients of T cell-depleted BMT the majority of these cells co-expressed p75 chain and CD56 antigen. IL-2-induced proliferation and lymphokine-activated killer (LAK) activity were detectable in all patients, and their values did not correlate with expression of p55 or p75 chains. Our data suggest that expansion of NK subsets expressing IL-2R chains after T cell-depleted BMT may be related to early reconstitution of natural immunity in the presence of allogeneic stimuli.     

Cobalt protoporphyrine IX-mediated heme oxygenase-I induction alters the inflammatory cytokine response, but not antigen presentation after experimental allogeneic bone marrow transplantation

Acute graft-versus-host disease (aGvHD) remains the major cause of mortality after allogeneic stem cell transplantation. Acute GvHD can be partially prevented when heme oxygenase-1 (HO-1) is induced in the recipient prior to transplantation but the mechanisms are not fully understood. Using a murine haploidentical bone marrow transplantation (BMT) model (C57Bl/6 right curved arrow B6D2F1) we tested whether HO-1 induction altered the alloreactive T cell response or rather modulated the inflammatory cytokine profile early after BMT. In vivo administration of cobalt protoporphyrin IX (CoPP) did not affect the expression of MHC class I and II or the costimulatory molecules CD80 and CD86 on murine peritoneal and on splenic dendritic cells (DCs). Allospecific T cell proliferation and interferon gamma secretion did not differ in mixed lymphocyte reactions using either CoPP-pretreated allogeneic recipients or control-treated DCs as stimulators. Furthermore, splenic DCs, isolated one to four days after BMT from CoPP-pretreated recipients did not show any differences in the expression of costimulatory molecules compared to untreated controls, and T cell expansion and the cytolytic capacity 14 days after BMT were equal in the control and CoPP-treated allogeneic groups. Serum tumor necrosis factor alpha levels were significantly reduced in CoPP-treated allogeneic recipients when compared to allogeneic controls and did not differ from the syngeneic recipients. Our results indicate that the protective effects of CoPP-mediated HO-1 induction on survival and aGvHD after allogeneic BMT involve a reduction in the proinflammatory cytokine milieu rather than alteration in allospecific T cell stimulation.     

Serum procalcitonin for differentiating bacterial infection from disease flares in patients with autoimmune diseases

Early differentiation between bacterial infections and disease flares in autoimmune disease patients is important due to different treatments. Seventy-nine autoimmune disease patients with symptoms suggestive of infections or disease flares were collected by retrospective chart review. The patients were later classified into two groups, disease flare and infection. C-reactive protein (CRP) and serum procalcitonin (PCT) levels were measured. The CRP and PCT levels were higher in the infection group than the disease flare group (CRP,11.96 mg/dL ± 9.60 vs 6.42 mg/dL ± 7.01, P = 0.003; PCT, 2.44 ng/mL ± 6.55 vs 0.09 ng/mL ± 0.09, P < 0.001). The area under the ROC curve (AUC; 95% confidence interval) for CRP and PCT was 0.70 (0.58-0.82) and 0.84 (0.75-0.93), which showed a significant difference (P < 0.05). The predicted AUC for the CRP and PCT levels combined was 0.83, which was not significantly different compared to the PCT level alone (P = 0.80). The best cut-off value for CRP was 7.18 mg/dL, with a sensitivity of 71.9% and a specificity of 68.1%. The best cut-off value for PCT was 0.09 ng/mL, with a sensitivity of 81.3% and a specificity of 78.7%. The PCT level had better sensitivity and specificity compared to the CRP level in distinguishing between bacterial infections and disease flares in autoimmune disease patients. The CRP level has no additive value when combined with the PCT level when differentiating bacterial infections from disease flares.     

Comparison of C-reactive protein and procalcitonin as predictors of postoperative infectious complications after elective colorectal surgery

Aim

To assess diagnostic value of perioperative procalcitonin (PCT) levels compared to C-reactive protein (CRP) levels in early detection of infectious complications following colorectal surgery.

Methods

This prospective observational study included 79 patients undergoing elective colorectal surgery. White blood cell count, CRP, and PCT were measured preoperatively and on postoperative days (POD) 1, 2, 3, 5, and patients were followed for postoperative complications. Diagnostic accuracy of CRP and PCT values on each day was analyzed by the receiver operating characteristics (ROC) curve, with infectious complications as an outcome measure. ROC curves with the largest area under the curve for each inflammatory marker were compared in order to define the marker with higher diagnostic accuracy.

Results

Twenty nine patients (36.7%) developed infectious complications. CRP and PCT concentrations increased in the early postoperative period, with a significant difference between patients with and without complications at all measured postoperative times. ROC curve analysis showed that CRP concentrations on POD 3 and PCT concentrations on POD 2 had similar predictive values for the development of infectious complications (area under the curve, 0.746 and 0.750, respectively) with the best cut-off values of 99.0 mg/L for CRP and 1.34 µg/L for PCT. Diagnostic accuracy of CRP and PCT was highest on POD 5, however the cut-off values were not considered clinically useful.

Conclusion

Serial postoperative PCT measurements do not offer an advantage over CRP measurements for prediction of infectious complications following colorectal surgery.Colorectal surgery leads to high rates of postoperative complications, varying between 28% and 38% (1-3). Early diagnosis and prompt treatment of complications is crucial for a favorable outcome. However, surgical trauma induces systemic inflammatory response syndrome (SIRS), which can hinder the diagnosis of postoperative infections (4). Therefore, it would be useful to find a biochemical marker that could accurately differentiate between infectious and non-infectious SIRS.C-reactive protein (CRP), the first of the acute phase proteins to be described, was discovered in 1930 and named for its capacity to precipitate a non-protein somatic fraction (Fraction C) of Streptococcus pneumoniae. It is a sensitive systemic marker of inflammation and tissue damage, but is not specific for infection (5,6). Surgical trauma induces a significant increase in CRP levels, which can reduce its predictive value for the diagnosis of infection in the early postoperative period (7-9). Despite this, an interest in CRP as an infection monitoring tool in the perioperative setting has increased since it was reported that in values higher than 140 mg/L on the postopertaive day (POD) 3-4 it well predicted infectious complications after colorectal surgery (10). Since then, several studies have found it to be a useful predictor of septic complications following colorectal and esophagogastric resections (11-15).Procalcitonin (PCT), the prohormone of calcitonin, was first described as a biochemical marker of infection in 1993 (16). Bacterial endotoxins are potent stimuli for PCT synthesis, which exhibits faster kinetics than CRP. PCT is released into the circulation 3-4 hours after an injection of endotoxin, reaching peak levels after 8-24 hours, while CRP peaks at 36-50 hours after stimulus (5,17). This would make PCT more suitable as an infection monitoring tool in the perioperative setting (18,19). A meta analysis of 33 studies, which included adults in intensive care units or after surgery and trauma, showed that PCT was a good diagnostic marker of sepsis, with greater diagnostic accuracy than CRP (20). Recent studies in surgical patients have also shown that after orthopedic, cardiac, and thoracic surgery PCT was better for detecting postoperative infections than CRP (21-23).To the best of our knowledge, no studies have compared the diagnostic accuracy of CRP and PCT for early detection of postoperative complications in patients undergoing colorectal surgery. The aim of this study was to assess the predictive value of serial postoperative determinations of CRP, PCT, and white blood cell (WBC) count for infectious complications after elective colorectal surgery and to compare the diagnostic accuracy of CRP and PCT.     

A prospective study of diagnosis of Toxoplasma gondii infection after bone marrow transplantation

Active infection with Toxoplasma gondii in immunocompromised transplant recipients can lead to toxoplasmosis, which may have a rapid disease course and in some cases be fatal. It is of paramount importance to diagnose toxoplasmosis at an early stage, and to initiate specific treatment to improve the outcome. Polymerase chain reaction (PCR) is today the primary diagnostic tool to diagnose toxoplasmosis in immunocompromised patients. Timely diagnosis may, however, be difficult if toxoplasmosis is at first asymptomatic. To investigate the magnitude of toxoplasmosis after bone marrow transplantation (BMT), we conducted a screening study by PCR where 21 autologous and 12 allogeneic BMT recipients were included. Peripheral blood samples were taken one week prior to BMT; thereafter, blood samples were drawn weekly for the first 6 months, and monthly up to one year after BMT. The samples were analyzed by conventional PCR and real-time PCR. T. gondii DNA was detected in peripheral blood from one patient 5 days post allogeneic BMT. There were no clinical signs of toxoplasmosis. Medical records were reviewed and showed a previously undiagnosed eye infection in another allogeneic BMT recipient. These two patients were seropositive for T. gondii. We concluded that monitoring for T. gondii DNA in peripheral blood samples using PCR might be a valuable method for identifying toxoplasma-seropositive stem cell transplant recipients.     

Significantly higher procalcitonin levels could differentiate Gram-negative sepsis from Gram-positive and fungal sepsis

Procalcitonin (PCT) levels can distinguish between infectious and non-infectious systemic inflammatory response. However, there are some differences between Gram-negative (G?), Gram-positive (G+), and fungal bloodstream infections, particularly in different cytokine profiles, severity and mortality. The aim of current study was to examine whether PCT levels can serve as a distinguishing mark between G+, G?, and fungal sepsis as well. One hundred and sixty-six septic patients with positive blood cultures were examined on C-reactive protein (CRP) and PCT on the same date of blood culture evaluation. The median (interquartile range, IQR) of CRP and PCT in G+, G?, and fungal cohorts and comparison of measured values between groups were made using the Kruskal–Wallis test with subsequent Bonferroni’s corrections, with p < 0.05. In 83/166 (50 %) of blood cultures, G+ microbes, 78/166 (47 %) G? rods, and 5/166 (3 %) fungi were detected. PCT concentrations (ng/ml) were significantly higher in G? compared to other cohorts: 8.90 (1.88; 32.60) in G?, 0.73 (0.22; 3.40) in G+, and 0.58 (0.35; 0.73) in fungi (p < 0.00001). CRP concentrations did not differ significantly in groups. Significantly higher PCT levels could differentiate G? sepsis from G+ and fungemia. In contrast to CRP, PCT is a good discriminative biomarker in different bloodstream infections.     

Pulmonary nodular lesions in bone marrow transplant recipients: impact of histologic diagnosis on patient management and prognosis

Bone marrow transplantation is associated with numerous pulmonary complications, which may manifest as nodules. We studied 33 bone marrow transplant (BMT) recipients in whom pulmonary nodular lesions (PNLs) developed during a 5-year period and who underwent open lung biopsy (OLB) for diagnosis. Of 33 patients with PNL, 15 (45%) had pulmonary cytolytic thrombi (PCT), a recently described condition characterized histologically by occlusive vascular lesions and hemorrhagic infarcts and clinically by a favorable outcome. Clinical symptoms and radiologic abnormalities disappeared during a period of a few weeks. None of the patients died of PCT; 10 were alive at last contact. The second most common cause of PNL (8/33 [24%]) was Aspergillus infection, which was the cause of death in 6. OLB is an effective way of obtaining diagnostic tissue in BMT recipients with PNLs. Histologic examination is accurate in determining the cause of PNLs and identifying lesions that have a favorable outcome and those that require a change in treatment.     

Functional hyposplenism following allogeneic bone marrow transplantation.

AIMS--To investigate the incidence of functional hyposplenism in a group of patients who had undergone allogeneic bone marrow transplantation (BMT). METHODS--Splenic function was assessed by counting the number of gluteraldehyde fixed red blood cells containing pits or indentations as examined by interference phase microscopy. Normal values are < 2% whereas splenectomy patients have values of 25 to 40%. RESULTS--Twenty eight BMT recipients (17 men, 11 women) were studied at varying periods post-transplant and the results compared with 20 healthy volunteers and 10 patients who had undergone splenectomy or had splenic atrophy because of haematological conditions. Of the 28 BMT recipients, one had undergone a prior splenectomy; of the remaining 27 patients, four (15%) had evidence of functional hyposplenism with between 5.0 and 34.0% pitted cells. Of these four patients, one had active extensive chronic graft versus host disease (GvHD) which has been previously reported to be associated with functional hyposplenism following transplantation. Only one of the four patients had peripheral blood red cell changes typical of hyposplenism. CONCLUSION--These results confirm that extensive chronic GvHD is associated with hyposplenism. Intermediate degrees of functional hyposplenism may also occur following BMT in the absence of chronic GvHD and in the absence of haematological features of hyposplenism on routine blood films. This may be of significance in mediating the susceptibility to infection with encapsulating bacteria seen following allogeneic BMT.     

Procalcitonin, a new marker for bacterial infections

Procalcitonin (PCT), the precursor protein of the hormone calcitonin, appears to be an early marker of the presence of severe systemic infection. High serum concentrations are associated with severe systemic bacterial, parasitic or fungal infections. In contrast, PCT is generally not induced by severe viral infections or inflammatory reactions of non-infectious origin. Hence, PCT can be used for differential diagnosis of bacterial and viral meningitis. PCT may be helpful in the differentiation between infectious and non-infectious origin of systemic inflammatory response syndrome (SIRS) and acute respiratory distress syndrome (ARDS), pancreatitis, cardiogenic shock and acute rejection of organ transplants. PCT monitoring may be useful in patients with high risk of bacterial infection (major surgery, trauma, immunocompromised patients). PCT is a very stable molecule in vitro, and its measurement requires only 20 ml of plasma or serum and can be done within 2 hours.     

CMV antigenemia following bone marrow transplantation: risk factors and outcomes.

Cytomegalovirus (CMV) infection remains a major problem in blood and bone marrow transplant (BMT) recipients. Recent efforts have been directed at prevention, early diagnosis, and treatment of CMV disease following BMT. Assay for CMV early antigen pp65 on circulating leukocytes has been shown to be sensitive, and specific in detecting early CMV infection. We examined the frequency, risk factors, and outcomes of a positive CMV antigen assay in 118 consecutive BMT patients. Forty-three (36%) of the 118 patients developed CMV antigenemia a median of 26 days post-BMT (range, -6 to 209 days). The incidence of antigenemia in autologous, related donor, and unrelated donor BMT recipients was 15%, 50%, and 48%, respectively (P < .01) and was lower in CMV-seronegative patients (19% versus 51% in seropositive patients; P < .01). Patients with grade II to IV acute graft-versus-host disease (GVHD) had 2.2 times the risk of antigenemia of patients with no or only limited GVHD (P = .03). Age at transplantation, underlying disease, CMV prophylaxis regimen, and GVHD prophylaxis regimen did not affect the risk of CMV antigenemia. Ten of the 43 antigenemic patients, all CMV-seropositive allogeneic BMT (alloBMT) recipients, developed CMV organ disease a median of 101 days (range, 28-283 daya) post-BMT. These data suggest that CMV-seropositive alloBMT patients are at highest risk for CMV antigenemia and for organ disease as well. CMV disease may occur before antigenemia is detectable in leukopenic patients and may also develop late post-BMT, even in patients still receiving antiviral prophylaxis. In high-risk groups, intensive surveillance continuing for more than 6 months after BMT may be indicated.