Mutations in the neutrophil elastase gene in cyclic and congenital neutropenia.

Severe neutropenia disorders are characterized by extremely low levels of peripheral blood neutrophils, a maturation block of bone marrow progenitor cells and recurring severe bacterial and fungal infections. Recent reports indicated that severe neutropenia is a consequence of an impaired survival and abnormal cell cycle progression of myeloid progenitor cells in both cyclic and severe congenital neutropenia. Mutations in the neutrophil elastase gene were identified in all patients with cyclic neutropenia and most of the patients with severe congenital neutropenia. We hypothesize that expression of mutant neutrophil elastase protein results in deregulation of intracellular activity and premature cell death of myeloid-committed progenitor cells in these disorders, resulting in the lack of peripheral blood neutrophils. The potential molecular mechanisms of mutant-protein-mediated neutropenia is discussed.     

Effect of orally administered heat-killed Enterococcus faecalis FK-23 preparation on neutropenia in dogs treated with cyclophosphamide

Dogs injected intravenously for 3 days with cyclophosphamide (CY) at a dose of 10 mg/kg were given 100 mg/kg of Enterococcus faecalis FK-23 preparation (FK-23) perorally for 14 days to confirm the beneficial effects of the latter drug in neutropenic dogs when orally administered. Although FK-23 treatment did not inhibit CY-induced neutropenia, it augmented neutrophil-reconstituting capacity in these dogs. Increases in the myeloid/ erythroid ratio and neutrophilic lineages were found in the bone marrow of FK-23 administered dogs. The oral administration significantly restored the reduced activity of neutrophil phagocytosis and chemiluminescence in dogs treated with CY. These findings indicate that FK-23 administered perorally not only augments neutrophil reconstitution through the activation of bone marrow but also functions in dogs treated with CY. It may thus be a useful supportive agent to reduce the adverse side-effects associated with the administration of chemotherapeutic agents such as CY.     

Potential role of autoantibody in severe neutropenia of a patient with Kawasaki Syndrome

Neutropenia associated with Kawasaki Syndrome (KS) has been rarely reported, and the detailed mechanisms responsible for this state are not yet elucidated. The aim of this study was to clarify the mechanisms of neutropenia in KS. We examined antibodies to known neutrophil antigens (HNA1a, HNA1b, HNA null, HNA2, HNA3, HNA4 and non-HLA antigen 9a) in a KS patient with neutropenia. We also performed the granulocyte immunofluorescence test (GIFT) using patient or control neutrophils incubated with the patient's serum at serial time points over the patient's clinical course. No specific antibody to known neutrophil antigens was detected. Flow cytometric analysis showed that autoantibodies bound to immature CD13-positive myeloid cells, which resulted in myeloid lineage maturation arrest in the bone marrow. GIFT showed that neutrophil-specific autoantibodies were produced by the patient, and the amount of autoantibody inversely correlated with the patient's neutrophil counts. The presence of an autoantibody to a novel antigen on immature myeloid cells or neutrophils is the likely the cause of severe neutropenia in this patient with KS.     

Effects of recombinant human granulocyte colony-stimulating factor on neutropenia in patients with congenital agranulocytosis

Congenital agranulocytosis is a disorder characterized by severe neutropenia and a profound deficiency of identifiable neutrophil progenitors in bone marrow. In an attempt to stimulate neutrophil production and thereby reduce the morbidity and mortality associated with this disease, we administered recombinant human granulocyte colony-stimulating factor (rhG-CSF) in doses of 3 to 60 micrograms per kilogram of body weight per day to five patients with congenital agranulocytosis. In all five patients, an increase in the number of neutrophils was noted eight to nine days after the initiation of the effective dosage (the dose at which the neutrophil count reached 1000 cells per microliter or more and the bone marrow showed granulocyte maturation beyond the myelocyte stage). The absolute neutrophil counts rose from less than 100 to between 1300 and 9500 cells per microliter. Marrow aspirates obtained after 14 days at the effective dosage showed maturation to the mature neutrophil stage. The side effects that were observed were medullary pain, splenomegaly, and an elevation of levels of leukocyte alkaline phosphatase. All five patients have had sustained neutrophil counts of 1000 cells per microliter or more for 9 to 13 months while receiving subcutaneous maintenance therapy. Preexisting chronic infections have resolved clinically, and the number of new infectious episodes and the requirement for intravenous antibiotics have decreased. We conclude that treatment with rhG-CSF can lead to a large increase in the numbers of functional neutrophils in patients with congenital agranulocytosis.     

Impaired glucose homeostasis,neutrophil trafficking and function in mice lacking the glucose-6-phosphate transporter

Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the glucose-6-phosphate transporter (G6PT). In addition to disrupted glucose homeostasis, GSD-Ib patients have unexplained and unexpected defects in neutrophil respiratory burst, chemotaxis and calcium flux, in response to the bacterial peptide f-Met-Leu-Phe, as well as intermittent neutropenia. We generated a G6PT knockout (G6PT-/-) mouse that mimics all known defects of the human disorder and used the model to further our understanding of the pathogenesis of GSD-Ib. We demonstrate that the neutropenia is caused directly by the loss of G6PT activity; that chemotaxis and calcium flux, induced by the chemokines KC and macrophage inflammatory protein-2, are defective in G6PT-/- neutrophils; and that local production of these chemokines and the resultant neutrophil trafficking in vivo are depressed in G6PT-/- ascites during an inflammatory response. The bone and spleen of G6PT-/- mice are developmentally delayed and accompanied by marked hypocellularity of the bone marrow, elevation of myeloid progenitor cell frequencies in both organs and a corresponding dramatic increase in granulocyte colony stimulating factor levels in both GSD-Ib mice and humans. So, in addition to transient neutropenia, a sustained defect in neutrophil trafficking due to both the resistance of neutrophils to chemotactic factors, and reduced local production of neutrophil-specific chemokines at sites of inflammation, may underlie the myeloid deficiency in GSD-Ib. These findings demonstrate that G6PT is not just a G6P transport protein but also an important immunomodulatory protein whose activities need to be addressed in treating the myeloid complications in GSD-Ib patients.     

Treatment of chemotherapy-induced neutropenia in a rat model by using multiple daily doses of oral administration of G-CSF-containing nanoparticles

Chemotherapy-induced neutropenia often increases the likelihood of life-threatening infections. In this study, a nanoparticle (NP) system composed of chitosan and poly(γ-glutamic acid) conjugated with diethylene triamine pentaacetic acid (γPGA-DTPA) was prepared for oral delivery of granulocyte colony-stimulating factor (G-CSF), a hematopoietic growth factor. The therapeutic potential of this NP system for daily administration of G-CSF to treat neutropenia associated with chemotherapy was evaluated in a rat model. In vitro results indicate that the procedures of NP loading and release preserved the structural integrity and bioactivity of the G-CSF molecules adequately. Those results further demonstrated the enzymatic inhibition activity of γPGA-DTPA towards G-CSF against intestinal proteases. Additionally, the in vivo biodistribution study clearly identified accumulations of G-CSF in the heart, liver, bone marrow, and urinary bladder, an indication of systemic absorption of G-CSF; its relative bioavailability was approximately 13.6%. Moreover, significant glucose uptake was observed in bone marrow during G-CSF treatment, suggesting increased bone marrow metabolism and neutrophil production. Consequently, neutrophil count in the blood increased in a sustained manner; this fact may help a patient's immune system recover from the side effects of chemotherapy.     

Risk factors of Ganciclovir-related neutropenia after allogeneic stem cell transplantation: a retrospective monocentre study on 547 patients

Cytomegalovirus (CMV) infection is a serious complication that may occur in the weeks or months following bone marrow transplantation. However, both Ganciclovir and the CMV infection itself can cause marrow toxicity, notably neutropenia, that may consequently expose these immunosuppressed patients to life-threatening bacterial and/or fungal infections. The aim of this retrospective study was to identify factors associated with the occurrence of grade III–IV neutropenia among patients receiving pre-emptive Ganciclovir therapy after allogeneic stem cell transplantation at our Institution. We identified 547 consecutive patients transplanted from January 2005 to June 2011 at our Institution. In all, 190 patients (35%) presented with CMV reactivation of whom 30 patients (5%) were excluded from the analysis because they already had neutropenia at the time of reactivation. Finally, 160 (29%) patients were analysed. According to multivariate analysis, at the time of treatment initiation, the risk factors significantly associated with a grade III–IV Ganciclovir-related neutropenia included a high viral load (hazard ratio (HR) = 2.68, 95% CI 1.25–5.737, p 0.01); an absolute neutrophil count >3000 was a protective factor (HR = 0.26, 95% CI 0.125–0.545, p <0001) whereas serum creatinine >2 mg/dL was associated with higher Ganciclovir-related neutropenia (HR = 2.4, 95% CI 1.11–5.17, p 0.002). This large analysis revealed three risk factors for Ganciclovir-related neutropenia among patients with CMV reactivation after allogeneic stem cell transplantation; prompt identification of patients at risk when antiviral therapy is started may allow clinicians to adopt adequate preventive measures, so reducing the morbidity and mortality associated with CMV reactivation.     

Granulocyte colony-stimulating factor treatment in AIDS patients

Summary Frequent complications of human immunodeficiency virus infection are hematopoietic failure and poor tolerance of myelosuppressive drugs. Reasons for neutropenia resulting from hematopoietic failure are infection of the bone marrow and hematotoxicity of treatment with zidovudine, ganciclovir, sulfonamides, and interferons. Moreover, tumor necrosis factor-, transforming growth factor- and interferon- have been shown to suppress proliferation of bone marrow cells. Both granulocyte (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) increase neutrophil counts and ameliorate phagocytic and bactericidic function of neutrophils. We report eight cases of AIDS patients with serious infections and neutropenia (< 750 cells/l), who were treated concomitantly with recombinant human G-CSF (3–4 g subcutaneously per kilogram body weight daily). G-CSF treatment was well tolerated in all patients and showed no side effects or disturbances of other lineages than neutrophils. Life-threatening bacterial infections were treated successfully by stimulating the neutrophil immune system. This therapy shortened the duration of subsequent treatment with antibiotics. Since human immunodeficiency virus infects CD4-positive monocytes and macrophages, which are stimulated by GM-CSF, G-CSF seems to be the cytokine of choice, if stimulation of the neutrophil lineage is warranted.Abbreviations G-CSF granulocyte colony-stimulating factor - GM-CSF granulocyte-macrophage colony-stimulating factor - HIV human immunodeficiency virus     

Recombinant granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for lymphoid cancer

BACKGROUND. The period of neutropenia after autologous bone marrow transplantation results in substantial morbidity and mortality. The results of previous phase I-II clinical trials suggest that recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) may accelerate neutrophil recovery and thereby reduce complications in patients after autologous bone marrow transplantation. METHODS. We conducted a randomized, double-blind, placebo-controlled trial at three institutions. The study design and treatment schedules were identical, and the results were pooled for analysis. One hundred twenty-eight patients were enrolled. Sixty-five patients received rhGM-CSF in a two-hour intravenous infusion daily for 21 days, starting within four hours of the marrow infusion, and 63 patients received placebo. RESULTS. No toxic effects specifically ascribed to rhGM-CSF were observed. The patients given rhGM-CSF had a recovery of the neutrophil count to 500 x 10(6) per liter 7 days earlier than the patients who received placebo (19 vs. 26 days, P less than 0.001), had fewer infections, required 3 fewer days of antibiotic administration (24 vs. 27 days, P = 0.009), and required 6 fewer days of initial hospitalization (median, 27 vs. 33 days; P = 0.01). There was no difference in the survival rate at day 100. CONCLUSIONS. In patients undergoing autologous bone marrow transplantation for lymphoid neoplasia, rhGM-CSF significantly lessens morbidity. Further studies will be required to establish its optimal dosage and schedule of administration.     

Mechanisms of tumor necrosis factor alpha-induced lymphopenia, neutropenia, and biphasic neutrophilia: a study of lymphocyte recirculation and hematologic interactions of TNF alpha with endogenous mediators of leukocyte trafficking

Tumor necrosis factor alpha (TNF) induces lymphopenia, neutropenia, and biphasic neutrophilia after intravenous injection of 3,000 U TNF in Lewis rats. The mechanism of TNF-induced lymphopenia was investigated by means of thoracic duct cannulation. Hourly measurements of lymphocyte recirculation via the thoracic duct failed to reveal any significant decrease in lymphocyte recirculation in TNF-treated vs. control rats, suggesting that a decrease in lymphocyte recirculation through the thoracic duct is not the mechanism for TNF-induced lymphopenia. The mechanism of TNF-induced neutropenia was investigated by administering TNF to rats in whom a neutrophilia had been induced with interleukin-1 (IL-1). In rats with neutrophilia, TNF resulted in a sharp decrease in the circulating neutrophil pool, demonstrating that TNF induces neutropenia by causing neutrophils to leave the circulating pool rather than decreasing neutrophil release from the marrow. The mechanism of neutropenia was furthermore shown to be due to the transient intravascular margination of neutrophils by administering epinephrine concomitantly with TNF. Epinephrine, which causes neutrophilia solely by demargination, abrogated the TNF-induced neutropenia and actually resulted in a neutrophilia that was greater than the neutrophilia occurring in epinephrine alone-treated rats, demonstrating both that TNF had already caused release of marrow neutrophils at the time of peripheral neutropenia, and that the paradoxical neutropenia was due to the transient intravascular margination of neutrophils. The known property of epinephrine to cause neutrophilia exclusively by demargination was proved by examination of the bone marrow of epinephrine-treated rats in whom no decrease in marrow neutrophils was observed (in contrast to TNF- and IL-1-treated rats in whom neutrophilia is accompanied by a depletion of marrow neutrophils). The mechanism of TNF-induced neutrophilia was investigated by modulating the magnitude of both the first and second peaks of neutrophilia by priming of rats with daily injections of IFN gamma for 2 days prior to administration of TNF. The first peak of neutrophilia in IFN gamma-primed TNF-treated rats was decreased in comparison to TNF alone-treated rats because of the well-known neutropenic and myelosuppressive effect of IFN gamma, which resulted in a decrease in the number of neutrophils that could be recruited to cause neutrophilia.(ABSTRACT TRUNCATED AT 400 WORDS)     

Neutrophil circulation and release from bone marrow during hypothermia.

The effect of hypothermia on neutrophil circulation and release from bone marrow has been studied. Pigs were anesthetized and maintained at 37 degrees C or surface cooled to 29 degrees C over 60 min. As the core temperature was reduced to 29 degrees C, the number of circulating neutrophils (X 10(9) per liter) fell from 6.0 +/- 0.6 to 2.3 +/- 0.3 by 60 min. No significant change in the number of circulating mature or immature neutrophils was observed over the 4 h of observation at 29 degrees C. Neutrophil demargination after administration of intravenous catecholamines was similar at 37 and 29 degrees C. Steroid stimulation of bone marrow to release neutrophils was markedly impaired at 29 degrees C. Circulating mature neutrophils in normothermic pigs increased from 5.6 +/- 1.2 to 10.4 +/- 1.2 by 120 min after administration of intravenous hydrocortisone sodium succinate. Circulating immature neutrophils increased from 1.7 +/- 0.3 to 5.3 +/- 0.4. At 29 degrees C, no significant changes in the number of circulating mature or immature neutrophils occurred. Endotoxin also failed to stimulate neutrophil release from the bone marrow. Furthermore, a marked neutropenia occurred in hypothermic pigs after intravenous endotoxin, which persisted for the 3 h of observation. Neutrophil circulation and release from bone marrow are compromised by hypothermia, which may increase the risk for bacterial infection.     

SerpinB1 protects the mature neutrophil reserve in the bone marrow

SerpinB1 is among the most efficient inhibitors of neutrophil serine proteases--NE, CG, and PR-3--and we investigated here its role in neutrophil development and homeostasis. We found that serpinB1 is expressed in all human bone marrow leukocytes, including stem and progenitor cells. Expression levels were highest in the neutrophil lineage and peaked at the promyelocyte stage, coincident with the production and packaging of the target proteases. Neutrophil numbers were decreased substantially in the bone marrow of serpinB1(-/-) mice. This cellular deficit was associated with an increase in serum G-CSF levels. On induction of acute pulmonary injury, neutrophils were recruited to the lungs, causing the bone marrow reserve pool to be completely exhausted in serpinB1(-/-) mice. Numbers of myeloid progenitors were normal in serpinB1(-/-) bone marrow, coincident with the absence of target protease expression at these developmental stages. Maturation arrest of serpinB1(-/-) neutrophils was excluded by the normal CFU-G growth in vitro and the normal expression in mature neutrophils of early and late differentiation markers. Normal absolute numbers of proliferating neutrophils and pulse-chase kinetic studies in vivo showed that the bone marrow deficit in serpinB1(-/-) mice was largely restricted to mature, postmitotic neutrophils. Finally, upon overnight culture, apoptosis and necrosis were greater in purified bone marrow neutrophils from serpinB1(-/-) compared with WT mice. Collectively, these findings demonstrate that serpinB1 sustains a healthy neutrophil reserve that is required in acute immune responses.     

Enhancement of antibacterial resistance of neutropenic, bone marrow-suppressed mice by interleukin-1 alpha.

The effect of recombinant human interleukin-1 alpha (IL-1) on the resistance of normal and bone marrow-suppressed mice against bacterial infection was evaluated. IL-1 induced neutrophilia and enhanced the resistance of normal mice against acute, systemic intraperitoneal infection with Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus. Mice with cyclophosphamide-induced bone marrow suppression were neutropenic and exhibited increased susceptibility to infection. Treatment of neutropenic C57BL/6 and C3H/HeJ mice with IL-1 before infection accelerated recovery of peripheral neutrophil counts and stimulated resistance against infection. Increases in neutrophils and enhancement of resistance induced by IL-1 were both dose and time dependent. Both neutrophilia and augmented resistance to infection were eliminated by a second dose of cyclophosphamide administered during the IL-1 treatments. Bone marrow-suppressed mice treated with IL-1 showed, at 4 h postinfection, greater increases in peripheral blood neutrophils and in numbers of peritoneal exudate neutrophils than suppressed mice treated with vehicle. The data suggest that the IL-1-stimulated recovery of myelopoiesis is an important factor in the enhancement of antibacterial resistance in bone marrow-suppressed, neutropenic mice. These findings indicate that IL-1 may be efficacious in limiting the duration of the neutropenia and of the increased risk for the development of bacterial infection associated with bone marrow suppression.     

Normal levels of constitutive and death receptor-mediated apoptosis of peripheral blood neutrophils from patients with chronic idiopathic neutropenia

To investigate the role of neutrophil apoptosis in the pathogenesis of chronic neutropenia, we examined constitutive and death receptor-mediated apoptosis ex vivo of peripheral blood neutrophils obtained from six chronic idiopathic neutropenia (CIN) patients and six healthy adult blood donors. Apoptosis was quantified based on phosphatidylserine externalization and caspase-3 activation in freshly isolated neutrophils or after overnight cultivation of neutrophils in the absence or presence of pro- or anti-apoptotic factors, including the pan-caspase inhibitor, zVAD-fmk. Neutrophils from CIN patients receiving treatment with granulocyte colony-stimulating factor appeared to be more prone to constitutive apoptosis than cells from untreated patients; however, further investigations in larger cohorts of patients are needed to validate these pilot studies. Overall, the level of neutrophil apoptosis was similar in patient and control groups, thus supporting the notion that the underlying defect in these neutropenia patients lies elsewhere, such as in the bone marrow microenvironment.     

Acute in vivo effects of IL-3 alone and in combination with IL-6 on the blood cells of the circulation and bone marrow.

Recombinant human IL-3 administered intravenously to rats as a single injection induced peripheral neutrophilia and monocytosis beginning at 4 to 6 hours after injection, peaking at 8 hours, and subsiding to normal by 12 to 24 hours. IL-3 did not induce an initial neutropenia such as accompanies endotoxin-, G-CSF-, and TNF-induced neutrophilia, or lymphopenia such as accompanies endotoxin-, IL-1-, and TNF-induced neutrophilia. The IL-3-induced peripheral neutrophilia was accompanied by a decrease in mature marrow neutrophils, indicating that the mechanism of neutrophilia was through marrow release rather than by demargination, which occurs after the administration of epinephrine or IL-6. The release of mature marrow neutrophils further suggests that IL-3 either has intrinsic neutrophil releasing activity or indirectly causes neutrophil release through the gene expression of a second cytokine. IL-3 induced a striking left-shifted myeloid hyperplasia in the bone marrow at 8 hours that morphologically was very similar to that observed after administration of endotoxin, a finding consistent with the hypothesis of previous investigators that endotoxin may in part act indirectly on hematopoietic cells by eliciting local marrow production of IL-3. Finally, IL-3 induced an increase in marrow pronormoblasts at 8 hours, consistent with the in vitro proliferative effect of IL-3 on erythroid stem cells. The combination of IL-3 and IL-6 induced a synergistic peripheral neutrophilia and monocytosis and a striking synergistic increase in marrow mast cells. The combination of IL-3 and IL-6 also induced an erythroid and left-shifted myeloid hyperplasia such as would be expected given the individual effects of these hematopoietic growth factors.     

Mechanisms of allergen- and LPS-induced bone marrow eosinophil mobilization and eosinophil accumulation into the pleural cavity: a role for CD11b/CD18 complex

OBJECTIVE: The mechanisms involved in bone marrow eosinophil emigration and recruitment to inflammatory sites are not fully understood. The involvement of CD11b/CD18 in marrow eosinophil release induced by lipopolysaccharide (LPS) or allergen was investigated in mice. METHODS: Eosinophil and neutrophil counts in the pleural cavity, blood and bone marrow were performed at different time intervals after the intrathoracic injection of LPS (250 ng/cavity) or ovalbumin (OVA, 12 microg/cavity; into actively sensitized mice) and compared to anti-CD11b/CD 18 (5C6, 1 mg/mouse) or anti-IL-5 (TRFK-5, 500 microg/kg) treated mice. RESULTS: LPS induced local eosinophil influx, that peaked within 24 h and that was preceded by a decrease in marrow eosinophils at 4 h. Antigenic challenge induced a decrease in marrow eosinophils within 4 h, followed by a long lasting pleural eosinophil accumulation and a persistent increase in marrow eosinophil numbers. Pretreatment with anti-CD11b/CD18 abolished LPS-induced neutrophil and eosinophil accumulation in the pleural cavity at 4 and 24 h, respectively. This pretreatment failed to modify neutrophil emigration from bone marrow, but significantly inhibited marrow eosinophil release at 4 h post-LPS or OVA challenge. Anti-IL-5 pretreatment failed to inhibit LPS-induced pleural eosinophil accumulation and mobilization from bone marrow, but it abolished allergen-induced effects, indicating a role for IL-5 in marrow eosinophil mobilization induced by antigen, but not by LPS challenge. CONCLUSIONS: Our results suggest that eosinophil migration induced by antigen or LPS into the pleural cavity is preceded by bone marrow eosinophil release through a mechanism that depends on CD11b/CD18.     

Early treatment with ganciclovir to prevent cytomegalovirus disease after allogeneic bone marrow transplantation.

BACKGROUND. Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality after allogeneic bone marrow transplantation. We conducted a controlled trial of ganciclovir for the early treatment of CMV infection in asymptomatic recipients of bone marrow transplants whose surveillance cultures for CMV became positive. METHODS. Bone marrow--allograft recipients who were seropositive for CMV antibodies or who received seropositive marrow were screened for CMV excretion by culture of throat swabs, blood, urine, or bronchoalveolar-lavage fluid. In this double-blind trial, 72 patients who had marrow engraftment and were excreting virus were randomly assigned to receive either placebo or ganciclovir (5 mg per kilogram of body weight twice a day for one week, followed by 5 mg per kilogram per day) for the first 100 days after transplantation. Patients were followed for the development of biopsy-confirmed CMV disease, ganciclovir-related toxicity, and survival. RESULTS. Between assignment to the study drug and day 100 after transplantation, CMV disease developed in only 1 of the 37 patients assigned to receive ganciclovir (3 percent), but in 15 of the 35 patients assigned to receive placebo (43 percent, P less than 0.00001). The ganciclovir recipients had rapid suppression of virus excretion; 85 percent had negative cultures after one week of treatment, as compared with 44 percent of the placebo group (P = 0.001). The principal toxic reaction was neutropenia; 11 ganciclovir recipients had an absolute neutrophil count below 0.75 x 10(9) per liter, as compared with 3 placebo recipients (P = 0.052). Treatment was discontinued in 11 ganciclovir recipients and 1 placebo recipient because of neutropenia (P = 0.003). After treatment was stopped, the neutrophil count recovered in all patients. Overall survival was significantly greater in the ganciclovir group than in the placebo group both 100 days and 180 days after transplantation (P = 0.041 and 0.027, respectively). CONCLUSIONS. Early treatment with ganciclovir in patients with positive surveillance cultures reduces the incidence of CMV disease and improves survival after allogeneic bone marrow transplantation.     

Prediction of the role of granulocyte-macrophage colony-stimulating factor in animals and man from in vitro results

The possibility of predicting the clinical effects of cytokines from in vitro data is discussed, using GM-CSF as an example. GM-CSF incubated with bone marrow cells has been shown to induce proliferation and colony formation, predominantly of the colony-forming unit granulocyte and granulocyte-macrophage types. Daily treatment of normal monkeys with GM-CSF resulted in transient neutropenia followed by neutrophilia. After withdrawal of GM-CSF the neutrophil levels returned to baseline. Predictably, GM-CSF administration results in accelerated neutrophil recovery in patients with chemotherapy-induced neutropenia. GM-CSF has also been shown to induce microbial killing by neutrophils and monocytes in vitro. This activity translated into a dose-related protection of GM-CSF-pretreated mice infected with lethal doses of micro-organisms. Interleukin-3 (IL-3) increases the cellularity of the bone marrow and GM-CSF can induce mobilization of bone marrow cells into the peripheral blood. Therefore, it was predicted and subsequently proved that a combination of these cytokines is synergistic, increasing the yields of peripheral blood progenitor cells which could be collected and then retransplanted into patients undergoing myeloablative chemotherapy. Monkeys injected with recombinant human IL-3 and GM-CSF had increased antibody titres to human IL-3 compared with monkeys given IL-3 alone, suggesting a potential use of GM-CSF which was not predicted from its in vitro results, that of vaccine adjuvancy. Thus, for any new mediator a broad range of tests of its activity in vitro may enable prediction of its activity in vivo, but it is also important to document any unexpected effects in in vivo studies which may give indications of new uses.     

Defective CSA-dependent granulopoiesis in patients with chronic drug-induced neutropenia

Colony stimulating activity (CSA) and granulocyte-macrophage progenitor cells (GM-CFC) were assayed in the bone marrow and peripheral blood of 17 patients with drug-induced chronic neutropenia. Leukocyte-derived and monocyte/macrophage-derived CSA from the neutropenic patients was found to be significantly decreased compared to normal control. However, bone marrow and peripheral blood GM-CFC were within normal limits. These data suggest that in neutropenic patients monocyte/macrophages exhibit most likely a qualitative defect in CSA production, which may account at least in part, for the impaired granulopoiesis observed in drug-induced neutropenia.     

Cyclic ultrastructural abnormalities in human cyclic neutropenia.

The ultrastructure of neutrophils from two brothers with cyclic neutropenia was studied at various time intervals of the neutrophil cycle, which varied from 15 to 21 days. During the nonneutropenic portion (middle third) of the cycle, when the blood neutrophil counts approached normal, the majority of blood and marrow segmented neutrophils appeared morphologically normal, whereas marrow promyelocytes demonstrated increased autophagy with decreased condensation of primary granules. During the early neutropenic portion of the cycle (first third), increased autophagy and granule abnormalities persisted in promyelocytes, myelocytes, and the few segmented neutrophils present. During the late neutropenic portion (last third) of the cycle, which preceded neutrophil recovery, most promyelocytes appeared morphologically normal, whereas the few segmented neutrophils present frequently contained increased autophagic and/or heterophagic vacuoles and decreased cytoplasmic granules. Abundant neutrophil debris was present in marrow macrophages consistent with dysgranulopoiesis and intramedullary destruction of abnormal myeloid cells. Similar changes were not observed in monocytes, eosinophils, or basophils. These results demonstrate a cyclic insult which has its initial morphologic impact on the promyelocyte of patients with cyclic neutropenia.