Depletion of gammadelta T cells exacerbates murine adriamycin nephropathy

It has been reported that the presence of gammadelta T cells in kidney is associated with kidney damage in human IgA nephropathy and in rat models of chronic renal injury, including Adriamycin nephropathy (AN), but the functional role of gammadelta T cells in this setting is unknown. This study examined the functional role of gammadelta T cells in tissue injury in a murine model of AN. Murine AN was induced in BALB/c mice by a single injection of Adriamycin. gammadelta T cells as a proportion of CD3(+) T cells were significantly increased in AN kidneys (16.8 +/- 3.9%) but not in lymph nodes (1.3 +/- 0.8%; P < 0.001). The proportion of gammadelta T cells in AN kidney correlated positively with serum creatinine and glomerular sclerosis. The Vgammadelta T cell receptor (TCR) repertoire in kidney showed expansion of a subset of cells that expressed Vgamma6/Vdelta1 genes and that used canonical TCR Vgamma6/Vdelta1 sequences in the CDR3 region of the TCR. gammadelta T cells that were sorted from the kidneys expressed TGF-beta but not IL-4, IL-10, or IFN-gamma. gammadelta T cells also expressed the activating receptor NKG2D and the NKG2D adaptor molecule DAP12. RAE-1, a ligand of NKG2D, was upregulated in AN kidney. Depletion of gammadelta T cells using anti-TCR gammadelta antibody resulted in worsening of serum creatinine, glomerulosclerosis, and interstitial inflammation. These studies indicate the involvement of the gammadelta T cell in innate recognition and regulation of inflammation in AN.     

Mycobacterial infection in HIV seropositive and seronegative populations, 1987-93.

BACKGROUND--Although the causes of the worldwide resurgence of tuberculosis are multifactorial, the HIV epidemic is believed to have had a central role. Control is further threatened by the emergence of multidrug-resistant tuberculosis. METHODS--A retrospective evaluation was undertaken of trends in pulmonary and extrapulmonary culture positive mycobacterial pathology, and the prevalence of drug-resistant tuberculosis in both HIV seropositive and, presumptively, HIV seronegative patients receiving their clinical care at St Mary's Hospital, London. Five hundred and thirty eight patients (188 of whom were known to be HIV seropositive) with positive mycobacterial isolates between January 1987 and March 1993 were identified from laboratory records. These were cross referenced with drug surveillance records. RESULTS--Overall, between 1987 and 1992 there was a progressive 3.5 fold increase in positive mycobacterial isolates and a 2.5 fold increase in patients with proven mycobacterial infection. This increase was greater within the HIV seropositive population. A total of 663 positive mycobacterial isolates was evaluated; the major pathogen identified was Mycobacterium tuberculosis (379 isolates, 57%). Three hundred and fourteen patients were diagnosed as having M tuberculosis, 49 of whom were HIV seropositive. M tuberculosis was predominantly isolated from the lung. Of 358 positive cultures for M tuberculosis (68 HIV seropositive, 290 presumptively HIV seronegative), only 27 isolates (7.6%), almost exclusively derived from presumed HIV seronegative patients, were resistant to either isoniazid, rifampicin, or both drugs together. No increases in drug-resistant isolates were observed over this period. CONCLUSIONS--There has been a considerable increase in the incidence of tuberculosis in both HIV seronegative and seropositive populations during the study period. The emergence of drug-resistant tuberculosis was not observed.     

直肠癌旁移行粘膜中γδ T细胞含量及受体基因重排的研究

目的 探讨直肠癌旁移行粘膜中γδＴ细胞含量和受体基因重排表达情况与直肠癌局部复发之间的关系,方法 运用双色免疫荧光标记流式细胞仪分析法和多聚酶链反应技术,检测１３例中低位直肠癌患者的癌旁移行粘膜上皮淋巴细胞（ＴＭＬ）,肿瘤浸润淋巴细胞（ＴＩＬ）,正常直肠粘膜上皮淋巴细胞（ＩＥＬ）中γδＴ细胞含量,γδＴ细胞受体δ链可变区（γδ－ＴＣＲＶδ）基因重排表达。结果 ＴＭＬ中γδＴ细胞的含量显著地高于ＴＩ     

Paradoxical reactions during tuberculosis treatment in patients with and without HIV co-infection

BACKGROUND: It has been suggested that deterioration of tuberculosis (TB) during appropriate treatment, termed a paradoxical reaction (PR), is more common and severe in HIV positive individuals on highly active antiretroviral therapy (HAART). METHOD: A study was undertaken to determine the frequency of PR and its associated features in a population of HIV+TB+ patients and a similar sized group of HIV-TB+ individuals. RESULTS: PR occurred in 28% of 50 HIV+TB+ patients and 10% of 50 HIV-TB+ patients. Disseminated TB was present in eight of 13 HIV+TB+ patients and four of five HIV-TB+ patients with PR. In 28 HIV+TB+ patients starting HAART, PR was significantly associated with commencing HAART within 6 weeks of starting antituberculosis treatment (p = 0.03) and was more common in those with disseminated TB (p = 0.09). No association was found between development of PR and baseline CD4 count or CD4 response to HAART. CONCLUSIONS: PR is common in HIV infected and uninfected individuals with TB. Early introduction of HAART and the presence of disseminated TB appear to be important in co-infected patients.     

Adverse events and treatment interruption in tuberculosis patients with and without HIV co-infection

BACKGROUND: Serious treatment associated adverse events are thought to occur more frequently in individuals with tuberculosis (TB) who are co-infected with HIV. A study was undertaken to assess the frequency of serious (grade III/IV) adverse events and interruption of anti-TB treatment in the era of effective antiretroviral therapy. METHODS: The incidence of serious adverse events was retrospectively compared in 312 individuals treated for TB, 156 of whom were co-infected with HIV. RESULTS: 111 HIV infected individuals (71%) received highly active antiretroviral therapy at the same time as anti-TB treatment. Serious adverse events were recorded in 40% HIV infected and 26% HIV uninfected individuals (p = 0.008). Peripheral neuropathy and persistent vomiting were more common in co-infected patients (p<0.001; p = 0.006), although all cause interruption of anti-TB treatment occurred with similar frequency in the two groups (13% in HIV infected patients and 15% in HIV uninfected patients; p = 0.74). In 85% of HIV infected patients and 87% of HIV uninfected individuals this was due to hepatotoxicity, which typically presented within 2 months of starting treatment. The median delay in restarting treatment was 4 weeks, so most individuals required full TB re-treatment. CONCLUSION: Despite a greater rate of serious (grade III/IV) adverse events among HIV infected individuals, discontinuation of anti-TB treatment occurred with a similar frequency in HIV infected and HIV uninfected individuals.     

Multiparameter Immune Profiling of Operational Tolerance in Liver Transplantation

Immunosuppressive drugs can be completely withdrawn in up to 20% of liver transplant recipients, commonly referred to as 'operationally' tolerant. Immune characterization of these patients, however, has not been performed in detail, and we lack tests capable of identifying tolerant patients among recipients receiving maintenance immunosuppression. In the current study we have analyzed a variety of biological traits in peripheral blood of operationally tolerant liver recipients in an attempt to define a multiparameter 'fingerprint' of tolerance. Thus, we have performed peripheral blood gene expression profiling and extensive blood cell immunophenotyping on 16 operationally tolerant liver recipients, 16 recipients requiring on-going immunosuppressive therapy, and 10 healthy individuals. Microarray profiling identified a gene expression signature that could discriminate tolerant recipients from immunosuppression-dependent patients with high accuracy. This signature included genes encoding for gammadelta T-cell and NK receptors, and for proteins involved in cell proliferation arrest. In addition, tolerant recipients exhibited significantly greater numbers of circulating potentially regulatory T-cell subsets (CD4+ CD25+ T-cells and Vdelta1+ T cells) than either non-tolerant patients or healthy individuals. Our data provide novel mechanistic insight on liver allograft operational tolerance, and constitute a first step in the search for a non-invasive diagnostic signature capable of predicting tolerance before undergoing drug weaning.     

Monitoring of human cytomegalovirus infections in heart transplant recipients by pp65 antigenemia

BACKGROUND: Rapid diagnostic techniques offer the opportunity of early diagnosis of human cytomegalovirus (CMV) infection in immunocompromized patients at risk of developing CMV disease and syndrome. The use of CMV pp65 antigenemia as a predictor of CMV syndrome and disease in heart transplant recipient after induction therapy was studied retrospectively. METHODS: One hundred and nineteen consecutive heart transplant recipients treated with induction therapy who survived more then 14 d were monitored for CMV infection. Ninety-four recipients were seropositive for CMV. Twenty-five recipients were seronegative for CMV and received grafts from seropositive donors. Pre-emptive therapy was used in seropositive patients when CMV pp65 antigenemia was greater than 50 antigen-positive cells per 2 x 10(5) peripheral blood leukocytes (PBL); prophylactic therapy was done only in seronegative recipient matched with seropositive donor. RESULTS: High-level CMV pp65 antigenemia (50 antigen-positive cells 2 x 10(5) PBL) occurred in 34% (41 of 119) of patients at a median of 44 d following transplantation. In seropositive recipients, 16% (15 of 94) of patients developed CMV invasive disease or syndrome, and in seronegative recipients 20% (5 of 25) of patients developed CMV disease or syndrome. Sixty-six per cent (62 of 94) of CMV seropositive patients were identified as not requiring pre-emptive therapy. In seropositive and seronegative recipients, the sensibility and negative predictive value of the cut-off level of 50 antigen positive cell for CMV disease and syndrome was 100%. The specificity was 79% and positive predictive value was 49%. CONCLUSION: Because of the excellent sensibility and negative predictive value of the cut-off level of 50 antigen positive cell per 2 x 10(5) PBL, application of pre-emptive therapy guided by high level of CMV pp65 antigenemia in the context of induction therapy allow to omit antiviral therapy in many at risk patients. In the context of pre-emptive and prophylactic therapy, the cut-off level of 50 antigen positive cell do not allow to predict with accuracy the development of CMV disease or syndrome.     

Human herpes virus 8 infection in kidney transplant patients from an area of northwestern Italy (Piemonte region).

BACKGROUND: Human herpes virus 8 (HHV-8) infection is associated with Kaposi sarcoma (KS) and other neoplastic and non-neoplastic manifestations. A strong association between HHV-8 and KS has been evidenced in transplant recipients, particularly kidney recipients. METHODS: We have investigated the HHV-8 seroprevalence by an immunoenzymatic assay in 408 patients awaiting kidney transplantation and in the corresponding 356 donors; moreover, we have tested for the presence of HHV-8 DNA by nested PCR in available serum samples of the same graft recipients at 6, 12 and >18 months post-transplantation (overall 156 specimens). Associated factors, such as age, sex, area of residence, potential for HHV-8 transmission via organ transplantation and development of KS were also investigated. RESULTS: Twenty (4.9%) of 408 patients and 7 (1.9%) of 356 donors were seropositive. HHV-8 seropositive patients were on average about 6 years older than seronegative individuals. No difference in prevalence by gender was found. Considering the area of residence of seropositive patients, 4/161 (2.48%) were resident in Piemonte vs 16/247 (6.47%) in other areas of Italy (P = n.s.). During the follow-up post-transplantation, HHV-8 DNA was found only in four patients who were seropositive before transplantation, in three cases the corresponding donor was seronegative, in one the corresponding donor was also seropositive and the recipient developed KS. At >18 months post-transplantation, two patients were HHV-8 DNA positive, both were seronegative pre-transplantation and their corresponding donors were seronegative. CONCLUSIONS: HHV-8 seroprevalence in the Piemonte region seems to be low, also in a population of kidney transplant recipients. Based on our data, it does not seem that the immunosuppressive regimen favours the reactivation of HHV-8. Our results do not suggest the possibility of HHV-8 transmission via organ transplantation. Incidence of KS among HHV-8 seropositive patients was very low.     

Cytomegalovirus as a risk factor in living-related renal transplantation. A prospective study.

Forty-four living-related donor kidney (LRD) recipients (19 HLA-identical and 25 haploidentical) were followed prospectively to determine the posttransplant incidence and sequelae of cytomegalovirus (CMV) infection as they relate to the CMV status of recipients and donors. CMV titers were measured in all patients before transplantation by an immunofluorescent assay (IFA). Recipients similarly had CMV titers measured at selected intervals after transplant and during febrile episodes. Appropriate viral cultures were simultaneously performed. Laboratory evidence of infection was correlated with symptoms and signs of active CMV disease. Mean follow-up period was 20 +/- 12 months with a range of 3-51 months. Three patients were excluded due to early acute rejection resulting in graft loss. Twenty-eight of 41 donors (68%) and 22 of 41 recipients (54%) had positive CMV titers before transplantation. Six of 41 recipients (15%) subsequently developed clinical and laboratory evidence of CMV infection: three of 19 seronegative recipients and three of 22 seropositive recipients. All six patients received kidneys from seropositive donors. Four patients had severe CMV disease (2 seronegative, 2 seropositive), whereas two patients had leukopenia and fever only. Two patients with severe CMV infections subsequently lost their grafts due to unrelated causes. Overall, actual patient and graft survival of the entire group is 95% and 82%, respectively. In conclusion, individuals who receive LRD kidneys from seronegative individuals are unlikely to develop CMV infection, and transplantation of seropositive LRD kidneys may be associated with transmission of CMV in susceptible recipients regardless of their serologic status. With appropriate management of CMV illness in the posttransplant period, LRD kidney donation is safe and efficacious and should not be discouraged on the basis of pretransplant CMV serology in any donor-recipient pairing.     

ICOS,SLAM and PD-1 expression and regulation on T lymphocytes reflect the immune dysregulation in patients with HIV-related illness with pulmonary tuberculosis

Background

Tuberculosis (TB) continues to be the most frequent cause of illness and death from an infectious agent globally, and its interaction with HIV is having devastating effects. To investigate how HIV alters the immune response to Mycobacterium tuberculosis (Mtb), we assessed basal and Mtb-induced proliferation, cytokine production, and expression of signalling lymphocytic activation molecule (SLAM), inducible costimulator (ICOS) and programmed death-1 (PD-1) on T lymphocytes from HIV-positive individuals coinfected with TB, HIV-positive subjects, TB patients and healthy donors (HD).

Findings

HIV-TB patients showed increased ICOS, SLAM and PD-1 basal levels on T lymphocytes, whereas HIV-positive individuals displayed elevated levels of SLAM and PD-1, TB patients high levels of SLAM, and HD low levels of the three proteins. Mtb-stimulation enhanced ICOS expression in the four groups, but only TB and HD increased SLAM and PD-1 levels.

Conclusions

These data show the immune deregulation that takes place during the immune response against TB in different study populations.     

Incidence and morbidity of cytomegalovirus disease associated with a seronegative recipient receiving seropositive donor-specific transfusion and living-related donor transplantation. A multicenter evaluation

This retrospective study was conducted to identify the frequency of cytomegalovirus (CMV) disease in seronegative recipients of donor-specific transfusion (DST) and living-related donor (LRD) kidneys from seropositive donors. A total of 151 LRD transplants (TX) were performed at six transplant centers over a 3-year period. A total of 33 patients were identified as having been seronegative (pre-TX) for CMV, yet they had DST and a TX from a seropositive LRD. Of these patients, 12 (36.4%) seroconverted within the first 6 months post-TX and developed clinical CMV disease. Additional patients seroconverted, but did not have evidence of clinical disease and were not tested further. All TX centers, with the exception of one, had seronegative patients that became ill after receiving a seropositive DST/LRD TX. Six patients manifested their disease as a febrile illness with leukopenia and liver enzyme elevations, four had pneumonitis, and two developed CMV ulcerations of the colon (one of whom died from resultant sepsis). Of the 36 seronegative patients who received seronegative DST/LRD TX none became ill with CMV disease. Of the 72 seropositive patients who received DST/LRD TX, only 2 (2.8%) developed CMV illness (one, seropositive into seropositive, the other, seronegative into seropositive). Of the 33 seronegative patients receiving seropositive DST/LRD TX, 17 received antilymphocyte preparations (ALP), and 8 of these became ill (47.1%). Of 16 patients not receiving ALP, 5 (31.3%) developed clinical CMV illness. Of the 33 patients who were identified as having been seronegative for CMV yet received seropositive DST/LRD TX, the 12 who did develop CMV illness had two graft losses, one death, and a serum creatinine for the remaining 9 patients of 2.3 +/- 1.6 at last follow-up. The remaining 21 patients who developed no illness had a serum creatinine of 1.3 +/- 0.6 with no graft losses at the last follow-up. This evidence suggests that a prospective TX recipient who is seronegative for CMV who receives DST/LRD TX from a seropositive family member has a significant risk for developing morbidity related to clinical CMV illness.     

Cytomegalovirus serologic status and postoperative infection correlated with risk of developing chronic rejection after pulmonary transplantation

Twenty-seven patients received pulmonary transplants during the period since we began routine use of cytomegalovirus-seronegative blood products for CMV-seronegative recipients. Preoperative serologic status of the recipient and the occurrence of cytomegalovirus infection in the postoperative period were correlated with development of obliterative bronchiolitis (OB) as diagnosed by transbronchial biopsy (TBB). Patients included 20 heart-lung and 7 double-lung recipients. OB occurred in 18 of 27 patients. All 3 CMV seronegative recipients receiving lungs from a seropositive donor and 9 of 10 CMV recipients seropositive at the time of transplantation developed OB compared with only 6 of 14 CMV seronegative patients receiving seronegative grafts (P = 0.018). CMV infection occurred in 10/27 patients, of whom 5 were asymptomatic; 90% of these patients developed OB. Donor-specific alloreactivity, based on primed lymphocyte testing (PLT) of bronchoalveolar lavage cells was found at the time of diagnosis of OB in 23 of 27 patients. A positive PLT was significantly associated with the presence of OB (P = 0.017). We conclude that preoperative seropositive status for CMV, grafting of organs from seropositive donors, and postoperative CMV infection are significant risk factors for developing OB. That OB is, in part, an immunologically mediated form of injury and represents chronic rejection is supported by the presence of donor-specific alloreactivity in BAL lymphocytes from all recipients with OB.     

Successful Immunotherapy of HCMV Disease Using Virus-Specific T Cells Expanded from an Allogeneic Stem Cell Transplant Recipient

Opportunistic infection remains the principal cause of mortality in allogeneic stem cell transplant recipients with active extensive chronic graft-versus-host disease. Human cytomegalovirus (HCMV) represents an important cause of disease in this setting and the toxicity of protracted and recurrent antiviral treatment together with eventual drug resistance represents a significant limitation to therapy. Although the expansion and adoptive transfer of HCMV-specific T cells from the healthy original donor can be an effective strategy to control viral replication, this is not possible when donors are seronegative or are subsequently inaccessible. Here we demonstrate for the first time, the successful expansion of HCMV-specific T cells from a seropositive transplant recipient of a seronegative graft with active HCMV disease and the long-term reconstitution of protective antiviral immunity following their adoptive transfer back into the patient.     

Prevention of primary cytomegalovirus infection after allogeneic bone marrow transplantation by using leukocyte-poor random blood products from cytomegalovirus-unscreened blood-bank donors

Cytomegalovirus infection was studied in 59 seronegative recipients of bone marrow depleted of lymphocytes by counterflow centrifugation. Eighteen patients died within 3 months after bone marrow transplantation without evidence of CMV infection, and they were excluded from analysis. Twenty-eight valuable seronegative patients received marrow from a seronegative donor, and 13 from a seropositive donor. All but 2 patients received acyclovir orally (4 x 400 mg/day) from days -9 to +60. CMV prophylaxis with immunoglobulin preparations was not given. All blood products were prepared from random, CMV-unscreened blood-bank donors. The red cell concentrates were depleted of leukocytes by filtration, and leukocytes were removed from the platelet concentrates by centrifugation. None of the patients with seronegative donors showed any clinical sign compatible with CMV infection. Two nonfatal primary CMV infections occurred in the recipients of bone marrow from CMV-positive donors. One of the 59 patients developed interstitial pneumonia, in this case caused by Pneumocystis carinii. Leukocyte depletion of blood products from random CMV-unselected blood donors appeared to prevent primary infection in CMV-seronegative BMT recipients. We conclude that prophylactic use of immunoglobulin preparations is not necessary to prevent CMV primo-infection in patients receiving leukocyte-depleted blood products and acyclovir prophylaxis during the first 2 months postgrafting.     

Cytokine expression in circulating T lymphocytes from patients undergoing carotid endarterectomy

AIM: We investigated a possible relationship of cytokine expression and phenotype features of circulating T lymphocytes with the histological type of atherosclerotic plaque removed during carotid endarterectomy. METHODS: Peripheral blood samples were taken from 20 patients with carotid atherosclerosis and from 8 healthy blood donors. Patients were divided into 2 groups according to the histological type of their atherosclerotic plaques (types V and VI). Expression of intracellular tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin-4 (IL-4), and of surface antigens (CD4, CD8, CD45RA, CD45RO, T cell receptor (TCR) alpha/beta, TCR gamma/delta) in circulating T lymphocytes was determined by 3-colour cytofluorimetric analysis. RESULTS: The percentage of T lymphocytes primed for TNF-alpha, IFN-gamma and IL-4 was higher in blood samples from patients than from healthy subjects; the difference was statistically significant for TNF-alpha-producing cells (p=0.01). In patients, the percentage of TNF-alpha-producing cells was significantly higher in the CD4+ subset than in the CD8+ subset (p=10(-4)). The percentage of TNF-alpha-, IFN-gamma- and IL-4-primed cells was higher in patients with type VI plaques (complicated lesions) than in patients with type V plaques (less complicated lesions). The difference was statistically significant for TNF-alpha-primed cells (p=0.05). No statistically significant differences were found in T cell phenotype features among patients or between patients and healthy subjects. CONCLUSION: Our results suggest a relationship between the percentage of circulating T lymphocytes expressing TNF-alpha and possibly IFN-gamma and IL-4 and the histological type of atherosclerotic plaque in patients with carotid artery disease.     

The role of pretransplant immunity in protection from cytomegalovirus disease following renal transplantation

To determine the extent to which pretransplant immunity resulting from natural infection protects against cytomegalovirus (CMV) disease, we analyzed CMV serology on 153 kidney donor and recipient pairs and followed transplant patients to determine incidence and severity of CMV disease. The overall incidence of CMV disease was 22%. Significant differences occurred in CMV disease incidence and severity, depending on the immune status of the kidney donor and recipient. Among recipients of kidneys from seropositive donors, immunity offered significant protection from CMV disease, reducing its incidence from 61% in nonimmune to 24% in immune patients (P less than 0.01). Pretransplant immune patients also had fever CMV-related complications. Among recipients of kidneys from seronegative donors, pretransplant immunity conferred a significant risk of CMV disease; immune patients had a 20% incidence of CMV disease compared with 2% in nonimmune patients (P less than 0.02). Disease was generally mild in all patients receiving kidneys from CMV infection had a 3-fold higher incidence of CMV disease than patients with reactivation infection (P less than 0.01). The incidence of CMV disease was similar in immune patients, whether they received a kidney from a seropositive or a seronegative donor. However, an important observation was that disease was significantly more severe in immune patients receiving a kidney from a seropositive donor (P less than 0.05). This indicates that if kidneys from seropositive donors are selected for use only in seropositive recipients, this places the immune patient at a higher risk for severe CMV disease. We conclude that pretransplant immunity offers a significant advantage to patients receiving kidneys from seropositive donors.     

Fever, human herpesvirus-6 (HHV-6) seroconversion, and acute rejection episodes as a function of the initial seroprevalence for HHV-6 in renal transplant recipients

Human herpesvirus-6 (HHV-6) is an opportunistic viral pathogen of emerging clinical significance in immunocompromised patients. We performed a seroepidemiological survey to test the relation between seroprevalence among donors and recipients for HHV-6 at three endpoints. Before transplantation sera obtained from cadaveric donors and from potential recipients were tested for IgG antibodies against HHV-6 using an enzyme-linked immunoassay. The group of recipient sera, including samples obtained before as well as 2, 4, 12, and 48 weeks after transplantation, were tested for anti-HHV-6 IgM antibodies using an indirect immunofluorescence assay. The statistical analysis was performed with the Cox proportional hazards models. The HHV-6 seronegative group (n = 11) compared with the HHV-6 seropositive group (n = 109) showed twice the risk of HHV-6 IgM seroconversion (RR = 2.24; P < .04), with a greater risk of fever, namely 3.8, which was on the verge of statistical significance. The opposite trend toward an association with acute rejection episodes was observed among HHV-6 seronegative patients (RR = 1.81). The presence of IgG antibody in the sera of donors to IgG seropositive recipients had no association with the occurrence of IgM seroconversion. In contrast, IgM antibodies to HHV-6 appeared in four of five seronegative patients who received allografts from IgG seropositive donors. These preliminary data suggest that the effects seem to be the consequence of HHV-6 transmission through a renal allograft.     

Prevention of lung infections associated with human immunodeficiency virus infection.

Current evidence indicates that the length of survival for patients with the acquired immunodeficiency syndrome (AIDS) is increasing, thereby affording a greater opportunity for strategies designed to prevent the infectious diseases that mark the syndrome. Because these infections may occur at different stages of immunosuppression caused by the human immunodeficiency virus (HIV), effective application of preventive measures depends not only on detection of HIV infection but also on the use of staging indicators. The diseases that serve to define AIDS, such as Pneumocystis carinii pneumonia, tend to occur late in the course of HIV infection and often when the T helper lymphocyte (CD4+ cells) count is less than 0.2 x 10(9)/l. Other infections, such as tuberculosis and pyogenic bacterial pneumonia, may develop at any point after HIV infection has occurred. Given this relation between the degree of immunosuppression and the occurrence of particular pulmonary infections, different preventive interventions should be applied at different times. It is now known that the incidence of several of the pulmonary infections that are common in patients with HIV infection can be reduced by prophylactic measures. Pneumocystis pneumonia is decreased in frequency by any one of several prophylactic agents, the best established being pentamidine administered as an inhaled aerosol. The role of isoniazid in the chemoprophylaxis of tuberculosis in patients not infected with HIV is well established. Although there is little evidence of benefit so far from isoniazid in HIV infected patients with a positive tuberculin skin test response, it is logical to assume that there could be some effect. The use of pneumococcal polysaccharide vaccine may also be of some benefit in reducing the frequency of pneumococcal pneumonia in patients with AIDS. In addition to these specific measures, the antiretroviral agent zidovudine decreases both the frequency and the severity of opportunist infections, at least during the first few months of treatment. A comprehensive strategy for prevention of HIV associated lung infection first requires detection of HIV seropositivity, staging the immunosuppression by the CD4+ cell count, and determining whether tuberculous infection is present by a tuberculin skin test. All seropositive individuals should be given pneumococcal vaccine and those with evidence of tuberculosis infection should be treated with isoniazid for one year. Zidovudine should probably be started when CD4+ cell counts are in the range 0.4-0.5 x 10(9)/l and prophylaxis against pneumocystis infection when CD4+ cell counts are in the range 0.2-0.3 x 10(9)/l.     

血液结核分枝杆菌液体培养在HIV感染者结核筛查中的应用评价

目的评价血液结核分枝杆菌液体培养对HIV感染者活动性结核病的诊断价值。方法 2006年8月至2008年7月,对广西省4个诊疗机构中HIV感染者进行包括临床、胸片、痰涂片、痰快速结核分枝杆菌培养和血液快速结核分枝杆菌培养在内的综合筛查以诊断活动性结核。分析结核分枝杆菌血培养在HIV感染者中的总体阳性率和在不同CD4水平患者中的阳性率,总结血培养阳性的结核病患者的临床特点,探讨血培养对结核的诊断价值。结果 602例HIV感染者在结核筛查时进行了血液结核分枝杆菌培养,7例检出结核分枝杆菌菌血症,血结核分枝杆菌培养在HIV感染者中的总体阳性率为1.2%。在CD4计数〈200/μl、〈100/μl和〈50/μl患者组中,血培养阳性率分别为1.4%、1.8%和2.4%,逐渐增高。共诊断活动性结核133例,其中结核分枝杆菌菌血症的阳性率为5.3%。血培养阳性的结核患者中位CD4仅为17/μl,均有明确的肺部影像学改变,2例有粟粒样表现,6例同时行痰结核分枝杆菌培养,其中5例（83%）阳性,5例患者伴有明确的肺外结核。与无结核分枝杆菌菌血症的结核/HIV合并感染者相比,有结核分枝杆菌菌血症的患者BMI和CD4计数较低,盗汗症状更常见。结论血液快速结核分枝杆菌培养在广西HIV感染者中的阳性率总体较低,但随着患者免疫缺陷的加重,阳性率逐渐增高。本研究中有结核分枝杆菌菌血症的HIV感染者均有明显肺部病变,且痰培养的阳性率高,提示结核分枝杆菌血培养对提高HIV感染者中结核的诊断率作用可能有限。