Polyamine metabolism impacts T cell dysfunction in the oral mucosa of people living with HIV.

Metabolic changes in immune cells contribute to both physiological and pathophysiological outcomes of immune reactions. Here, by comparing protein expression, transcriptome, and salivary metabolome profiles of uninfected and HIV+ individuals, we found perturbations of polyamine metabolism in the oral mucosa of HIV+ patients. Mechanistic studies using an in vitro human tonsil organoid infection model revealed that HIV infection of T cells also resulted in increased polyamine synthesis, which was dependent on the activities of caspase-1, IL-1ß, and ornithine decarboxylase-1. HIV-1 also led to a heightened expression of polyamine synthesis intermediates including ornithine decarboxylase-1 as well as an elevated dysfunctional regulatory T cell (TregDys)/T helper 17 (Th17) cell ratios. Blockade of caspase-1 and polyamine synthesis intermediates reversed the TregDys phenotype showing the direct role of polyamine pathway in altering T cell functions during HIV-1 infection. Lastly, oral mucosal TregDys/Th17 ratios and CD4 hyperactivation positively correlated with salivary putrescine levels, which were found to be elevated in the saliva of HIV+ patients. Thus, by revealing the role of aberrantly increased polyamine synthesis during HIV infection, our study unveils a mechanism by which chronic viral infections could drive distinct T cell effector programs and Treg dysfunction.

Oral immune dysfunction is associated with the expansion of FOXP3+PD-1+Amphiregulin+ T cells during HIV infection.

Residual systemic inflammation and mucosal immune dysfunction persist in people living with HIV, despite treatment with combined anti-retroviral therapy, but the underlying immune mechanisms are poorly understood. Here we report that the altered immune landscape of the oral mucosa of HIV-positive patients on therapy involves increased TLR and inflammasome signaling, localized CD4+ T cell hyperactivation, and, counterintuitively, enrichment of FOXP3+ T cells. HIV infection of oral tonsil cultures in vitro causes an increase in FOXP3+ T cells expressing PD-1, IFN-γ, Amphiregulin and IL-10. These cells persist even in the presence of anti-retroviral drugs, and further expand when stimulated by TLR2 ligands and IL-1ß. Mechanistically, IL-1ß upregulates PD-1 expression via AKT signaling, and PD-1 stabilizes FOXP3 and Amphiregulin through a mechanism involving asparaginyl endopeptidase, resulting in FOXP3+ cells that are incapable of suppressing CD4+ T cells in vitro. The FOXP3+ T cells that are abundant in HIV-positive patients are phenotypically similar to the in vitro cultured, HIV-responsive FOXP3+ T cells, and their presence strongly correlates with CD4+ T cell hyper-activation. This suggests that FOXP3+ T cell dysregulation might play a role in the mucosal immune dysfunction of HIV patients on therapy.

HCV coinfection of the HIV-infected patients with discordant CD4+ T-cell response to antiretroviral therapy leads to intense systemic inflammation.

The level of proinflammatory markers was assessed in HIV-infected patients that were coinfected with hepatitis C virus (HCV) and had failed to restore the CD4+ T cell counts (immunological nonresponders, INR) during the antiretroviral therapy (ART). Among four patient groups (HIV+HCV- and HIV+HCV+ subjects with the concordant response to ART; HIV+HCV- and HIV+HCV+ subjects that were INR), the greatest systemic inflammation was in the latter group. The maximum difference was between the subjects HIV+HCV-INR and HIV+HCV+ INR: the blood of coinfected patients contained significantly higher concentrations of the IP-10, sCD163, sTNF-RI, and sTNF-RII and of bacterial lipopolysaccharide. Systemic inflammation in HIV/HCV coinfected patients with the discordant response to ART is probably caused by a breach of hepatic barrier for the intestine products.

Safety and efficacy of BAY 94-9027, a prolonged-half-life factor VIII.

Essentials Recombinant factor VIII BAY 94-9027 conjugates in a site-specific manner with polyethylene glycol. BAY 94-9027 was given to patients with severe hemophilia A as prophylaxis and to treat bleeds. BAY 94-9027 prevented bleeds at dose intervals up to every 7 days and effectively treated bleeds. BAY 94-9027 treatment was mainly well tolerated and no patient developed factor VIII inhibitors. Click to hear Dr Tiede's perspective on half-life extended factor VIII for the treatment of hemophilia A SUMMARY: Background BAY 94-9027 is a B-domain-deleted prolonged-half-life recombinant factor VIII (FVIII) that conjugates in a site-specific manner with polyethylene glycol. Objective Assess efficacy and safety of BAY 94-9027 for prophylaxis and treatment of bleeds in patients with severe hemophilia A. Patients/methods In this multinational, phase 2/3, partially randomized, open-label trial, men aged 12-65 years with FVIII < 1% and ≥ 150 exposure days to FVIII received BAY 94-9027 for 36 weeks on demand or prophylactically at intervals determined following a 10-week run-in period on 25 IU kg-1 body weight two times per week. Patients with > 1 bleed during the run-in subsequently received 30-40 IU kg-1 two times per week; patients with ≤ 1 bleed were eligible for randomization to every-5-days (45-60 IU kg-1 ) or every-7-days (60 IU kg-1 ) prophylaxis (1 : 1) for 26 additional weeks until randomization arms were filled. Patients who were eligible but not randomized continued twice-weekly prophylaxis. The primary efficacy outcome was annualized bleeding rate (ABR). Results The intent-to-treat population included 132 patients (prophylaxis, n = 112; on demand, n = 20). Median ABR (quartile [Q1; Q3]) for patients treated two times per week who were not eligible for randomization (n = 13) improved after dose increase (17.4 [14.3; 26.0] to 4.1 [2.0; 10.6]). Median ABR for patients randomized to every-5-days treatment (n = 43) was 1.9 (0; 4.2), similar to patients eligible for randomization but who continued treatment two times per week (n = 11). Median ABR for 32/43 patients (74%) who continued every-7-days prophylaxis until study end was 0.96 (0.0; 4.3). Six hundred and thirty-six of 702 bleeds (90.6%) were controlled with ≤ 2 infusions. No patient developed a FVIII inhibitor. Conclusions BAY 94-9027 prevented bleeding across three individually tailored dose regimens and was effective for treatment of bleeds.

Systemic inflammation and liver damage in HIV/hepatitis C virus coinfection.

OBJECTIVES: Chronic hepatitis C virus (HCV) and HIV viral infections are characterized by systemic inflammation. Yet the relative levels, drivers and correlates of inflammation in these settings are not well defined. METHODS: Seventy-nine HIV-infected patients who had been receiving antiretroviral therapy (ART) for more than 2 years and who had suppressed plasma HIV levels (< 50 HIV-1 RNA copies/mL) were included in the study. Two patient groups, HCV-positive/HIV-positive and HCV-negative/HIV-positive, and a control group comprised of healthy volunteers (n = 20) were examined. Markers of systemic inflammation [interleukin (IL)-6, interferon gamma-induced protein (IP)-10, soluble tumour necrosis factor receptor-I (sTNF-RI) and sTNF-RII], monocyte/macrophage activation [soluble CD163 (sCD163), soluble CD14 and neopterin], intestinal epithelial barrier loss [intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide (LPS)] and coagulation (d-dimers) were analysed. CD4 naïve T cells and CD4 recent thymic emigrants (RTEs) were enumerated. RESULTS: Plasma levels of IP-10, neopterin and sCD163 were higher in HCV/HIV coinfection than in HIV monoinfection and were positively correlated with indices of hepatic damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the AST to platelet ratio index (APRI)]. Levels of I-FABP were comparably increased in HIV monoinfection and HIV/HCV coinfection but LPS concentrations were highest in HCV/HIV coinfection, suggesting impaired hepatic clearance of LPS. Plasma HCV levels were not related to any inflammatory indices except sCD163. In coinfected subjects, a previously recognized relationship of CD4 naïve T-cell and RTE counts to hepatocellular injury was defined more mechanistically by an inverse relationship to sCD163. CONCLUSIONS: Hepatocellular injury in HCV/HIV coinfection is linked to elevated levels of certain inflammatory cytokines and an apparent failure to clear systemically translocated microbial products. A related decrease in CD4 naïve T cells and RTEs also merits further exploration.

Prevention of SHIV transmission by topical IFN-ß treatment.

Understanding vaginal and rectal HIV transmission and protective cellular and molecular mechanisms is critical for designing new prevention strategies, including those required for an effective vaccine. The determinants of protection against HIV infection are, however, poorly understood. Increasing evidence suggest that innate immune defenses may help protect mucosal surfaces from HIV transmission in highly exposed, uninfected subjects. More recent studies suggest that systemically administered type 1 interferon protects against simian immunodeficiency virus infection of macaques. Here we hypothesized that topically applied type 1 interferons might stimulate vaginal innate responses that could protect against HIV transmission. We therefore applied a recombinant human type 1 interferon (IFN-ß) to the vagina of rhesus macaques and vaginally challenged them with pathogenic simian/human immunodeficiency virus (SHIV). Vaginal administration of IFN-ß resulted in marked local changes in immune cell phenotype, increasing immune activation and HIV co-receptor expression, yet provided significant protection from SHIV acquisition as interferon response genes were also upregulated. These data suggest that protection from vaginal HIV acquisition may be achieved by activating innate mucosal defenses.

[Biocompatibility of composites--literature review].

Composites are a large family of materials composed of polymer matrices imbedded with different types of fillers. The specific properties achievable with diverse chemical combinations provide for a wide range of implications in many industrial fields. Materials designed for medical use must not only efficiently serve the purpose of their use, but also be biocompatible to the tissues they contact and the body as a whole. Dental composites and their components have been studied intensely to assess their potential local and systemic side effects, to establish biocompatibility, in order to receive the proper conformation allowing their safe clinical use. The purpose of the following paper is to summarize several aspects of research focused on determining cytotoxicity, genotoxicity, carcinogenicity, hypersensitivity, and microbial effects of composite components, in order to ascertain in fact how biocompatible dental composite materials are. Research shows that several chemical components may be released from different types of composites, and are able to cause toxic, allergic, mutagenic and other biological effects. However, because of the small amounts applied and the unique conditions in the oral cavity, the clinical relevance of these findings is questionable. Nevertheless, caution should be taken when using these materials, to avoid possible negative outcomes. Future studies should focus on targeting most toxic components and finding biocompatible alternatives and development of materials with high polymerization efficiency in order to reduce the amount of leachable components.

Markers of inflammation and CD8 T-cell activation, but not monocyte activation, are associated with subclinical carotid artery disease in HIV-infected individuals.

OBJECTIVES: The aim of the study was to explore the relationships between lymphocyte and monocyte activation, inflammation, and subclinical vascular disease among HIV-1-infected patients on antiretroviral therapy (ART). METHODS: Baseline mean common carotid artery (CCA) intima-media thickness (IMT) and carotid plaque (IMT > 1.5 cm) were evaluated in the first 60 subjects enrolled in the Stopping Atherosclerosis and Treating Unhealthy Bone with Rosuvastatin in HIV (SATURN-HIV) trial. All subjects were adults on stable ART with evidence of heightened T-cell activation (CD8(+)CD38(+)HLA-DR(+) ≥ 19%) or increased inflammation (high-sensitivity C-reactive protein ≥ 2 mg/L). All had fasting low-density lipoprotein (LDL) cholesterol ≤ 130 mg/dL. RESULTS: Seventy-eight per cent of patients were men and 65% were African-American. Median (interquartile range) age and CD4 count were 47 (43, 52) years and 648 (511, 857) cells/µL, respectively. All had HIV-1 RNA < 400 HIV-1 RNA copies/mL. Mean CCA-IMT was correlated with log-transformed CD8(+)CD38(+)HLA-DR(+) percentage (r = 0.326; P = 0.043), and concentrations of interleukin-6 (r = 0.283; P = 0.028), soluble vascular cell adhesion molecule (sVCAM; r = 0.434; P = 0.004), tumour necrosis factor-α receptor-I (TNFR-I; r = 0.591; P < 0.0001) and fibrinogen (r = 0.257; P = 0.047). After adjustment for traditional cardiovascular disease (CVD) risk factors, the association with TNFR-I (P = 0.007) and fibrinogen (P = 0.033) remained significant. Subjects with plaque (n = 22; 37%) were older [mean (standard deviation) 51 (7.7) vs. 43 (9.4) years, respectively; P = 0.002], and had a higher CD8(+)CD38(+)HLA-DR(+) percentage [median (interquartile range) 31% (24, 41%) vs. 23% (20, 29%), respectively; P = 0.046] and a higher sVCAM concentration [mean (standard deviation) 737 (159) vs. 592 (160) ng/mL, respectively; P = 0.008] compared with those without plaque. Pro-inflammatory monocyte subsets and serum markers of monocyte activation (soluble CD163 and soluble CD14) were not associated with CCA-IMT or plaque. CONCLUSIONS: Participants in SATURN-HIV have a high level of inflammation and immune activation that is associated with subclinical vascular disease despite low serum LDL cholesterol.

Effects of recombinant human interleukin 7 on T-cell recovery and thymic output in HIV-infected patients receiving antiretroviral therapy: results of a phase I/IIa randomized, placebo-controlled, multicenter study.

BACKGROUND: The immune deficiency of human immunodeficiency virus (HIV) infection is not fully corrected with ARV therapy. Interleukin-7 (IL-7) can boost CD4 T-cell counts, but optimal dosing and mechanisms of cellular increases need to be defined. METHODS: We performed a randomized placebo-controlled dose escalation (10, 20 and 30 µg/kg) trial of 3 weekly doses of recombinant human IL-7 (rhIL-7) in ARV-treated HIV-infected persons with CD4 T-cell counts between 101 and 400 cells/µL and plasma HIV levels <50 copies/mL. Toxicity, activity and the impact of rhIL-7 on immune reconstitution were monitored. RESULTS: Doses of rhIL-7 up to 20 µg/kg were well tolerated. CD4 increases of predominantly naive and central memory T cells were brisk (averaging 323 cells/µL at 12 weeks) and durable (up to 1 year). Increased cell cycling and transient increased bcl-2 expression were noted. Expanded cells did not have the characteristics of regulatory or activated T cells. Transient low-level HIV viremia was seen in 6 of 26 treated patients; modest increases in total levels of intracellular HIV DNA were proportional to CD4 T-cell expansions. IL-7 seemed to increase thymic output and tended to improve the T-cell receptor (TCR) repertoire in persons with low TCR diversity. CONCLUSIONS: Three weekly doses of rhIL-7 at 20 µg/kg are well tolerated and lead to a dose-dependent CD4 T-cell increase and the broadening of TCR diversity in some subjects. These data suggest that this rhIL-7 dose could be advanced in future rhIL-7 clinical studies. CLINICAL TRIALS REGISTRATION: NCT0047732.

Genetic variations in loci relevant to natural killer cell function are affected by ethnicity but are generally not correlated with susceptibility to HIV-1.

Polymorphisms in cell surface receptors of natural killer cells and their ligands on target cells can affect susceptibility to viral infections including human immunodeficiency virus (HIV)-1. We found that the carriage of the human leukocyte antigen (HLA)-G minus 14-bp polymorphism, LILRB1 single nucleotide polymorphism rs1061680, and activating and inhibitory killer immunoglobulin-like receptors (KIRs) were different when data were compared between Caucasian, African Americans and Asian populations. However, carriage was similar when HIV-1 patients were compared with control donors, with the exception of the African American cohort.

Lower peripheral blood CD14+ monocyte frequency and higher CD34+ progenitor cell frequency are associated with HBV vaccine induced response in HIV infected individuals.

We evaluated immunologic predictors of response to HBV vaccine administered in the presence or absence of GM-CSF in HIV infected individuals. We measured peripheral blood hematopoietic progenitor, monocyte and myeloid-derived suppressor cell (MDSC) frequencies, and expression of GMCSF receptor on monocytes and MDSCs, at baseline and 4weeks after immunization in relation to antibody response. We observed higher baseline progenitor and lower monocyte frequencies among week 16 antibody responders. Week 4 decline in MDSC frequency was associated with week 16 antibody response, while administration of GM-CSF was associated with preservation of these cells. No significant differences in GM-CSF receptor expression were observed in the presence vs. absence of GM-CSF. These findings are consistent with a positive role of progenitor cells and a potential negative role of monocytes in vaccine response. Additionally, GM-CSF augmented the preservation of peripheral blood MDSC, which may contribute to the lack of improved vaccine responses.

Role of human beta-defensins in HIV infection.

Mechanisms of resistance to HIV-1 infection in the human oral cavity are incompletely understood. While salivary components have been implicated in protection, there is growing evidence that human beta-defensins (hBDs), originating in oral epithelial cells, may be playing an important role in the prevention of HIV infection. New antiviral, chemotactic, and immunosurveillance properties are being attributed to hBDs, which are small cationic antimicrobial innate response molecules expressed in mucosal epithelium. Inducible hBDs are always expressed in normal oral epithelium, a property not shared by other mucosal barriers. Data reviewed in this paper demonstrate that: (1) HIV-1 X4 and R5 phenotypes induce hBD-2 and -3 mRNA in normal human oral epithelial cells; (2) hBD-2 and -3 inhibit HIV-1 infection by both viral strains, with greater activity against X4 viruses; and (3) this inhibition is due to a direct interaction with virions and through modulation of the CXCR4 co-receptor. These properties may be exploited as strategies for mucosal protection against HIV-1 transmission.

Gender differences in human immunodeficiency virus (HIV) RNA and CD4 cell counts among new entrants to HIV care.

Clinic database extraction identified 806 new entrants to human immunodeficiency virus (HIV) care in Cleveland, OH, USA. At entry, women had higher CD4 counts and lower HIV RNA levels than men (mean, 388 vs. 310 cells/microL, and 8.94 x 10(4) vs. 1.27 x 10(5) copies/mL, respectively), but the proportion of entrants with category C illnesses, category B conditions, sexually transmitted diseases and CD4 counts < 200 microL did not differ between genders. Hepatitis B seroprevalence was higher in men (8.7% vs. 0.6%), but there was no difference in hepatitis C prevalence. Whether women in Cleveland seek HIV care earlier, or whether early markers of HIV disease differ between the genders, remains to be determined.

Computerised analysis of liver texture with correlation to needle biopsy.

AIM: To assist in tissue characterisation for the non-invasive diagnosis of diffuse fatty liver infiltration by providing quantitative indices of ultrasonic (US) backscatter with correlation to histology. METHODS AND MATERIALS: US images from patients referred to US-guided liver needle biopsy (LNB) for persistently elevated liver enzymes or serologically positive markers for viral hepatitis were recorded. The histopathological reports were reviewed. Steatosis, inflammation and degree of fibrosis were scored from 0 (normal) to 3 (severe). Patients with level 3 steatosis without inflammation or fibrosis were selected. US images from twenty-four healthy subjects served as control. Four textural indices were calculated for a selected ROI corresponding to the biopsy site. Sensitivity and specificity of discrimination between the two groups were evaluated. RESULTS: Fatty and healthy livers formed two distinct clusters. However, in all parametric subspaces there was a slight overlap between the groups with a few numbers of cases located across the dichotomy line.The sensitivity for all the indices was high (90 - 100 %). The specificity for each of the indices was moderate. The co-occurrence local homogeneity index yielded the highest specificity (88.5 %), with a sensitivity equivalent to two of the other indices (90 %). CONCLUSIONS: Highly accurate "ultrasonic biopsy" may be obtained for severe fatty liver. The described indices can serve as a tool in US computer- aided diagnosis (CAD) of diffuse parenchymal liver disease, in particular for severe steatosis of the liver.

Anatomical site predilections of non-Hodgkin's lymphoma in human immunodeficiency virus infection: a report on 54 cases.

OBJECTIVE: To identify and describe the primary anatomic sites of non-Hodgkin's lymphoma arising in the setting of Human Immunodeficiency Virus infection. DESIGN: Prospective (ongoing) study. SETTING: Kenyatta National Hospital a referral and teaching hospital in Kenya. SUBJECTS AND METHODS: Patients (n=54) with human immunodeficiency virus with associated non-Hodgkin's lymphoma managed at the Kenyatta National hospital from January 2001 to December 2003. Relevant clinical information obtained by medical history, physical examination and investigations. RESULTS: Of the 54 patients studied 29(54%) were males and 25(46%) females with median age 36 and range 20 to 61 years. Fifty (93%) had high grade and four (7%) intermediate grade lymphoma, the former had 15 (30%) Burkitt's and the rest large cell lymphoma. The stages at diagnosis were IV 35(65%), III 14(26%) and II 5(9%) and all had B symptoms. The primary sites at presentation to the hospital were peripheral nodes 16(30%), abdominal 15(28%), pectoral/chest wall 11(20%), central nervous system eight (15%) and systemic/generalised, four (7%). CONCLUSION: This study demonstrates that there were preferred anatomical sites of involvement by HIV associated non-Hodgkin's lymphomas and the finding of pectoral/ chest involvement in this series may not be coincidental. Further, this study suggests that anatomical sites predilection may be due to the tendency of viral associated malignancies to home to specific anatomic sites and also due to the anatomy of the lymphoreticular system. Studying virus pathogenesis in malignancies should consider also the anatomic sites involved.

Methodology to predict long-term cancer survival from short-term data using Tobacco Cancer Risk and Absolute Cancer Cure models.

Three parametric statistical models have been fully validated for cancer of the larynx for the prediction of long-term 15, 20 and 25 year cancer-specific survival fractions when short-term follow-up data was available for just 1-2 years after the end of treatment of the last patient. In all groups of cases the treatment period was only 5 years. Three disease stage groups were studied, T1N0, T2N0 and T3N0. The models are the Standard Lognormal (SLN) first proposed by Boag (1949 J. R. Stat. Soc. Series B 11 15-53) but only ever fully validated for cancer of the cervix, Mould and Boag (1975 Br. J. Cancer 32 529-50), and two new models which have been termed Tobacco Cancer Risk (TCR) and Absolute Cancer Cure (ACC). In each, the frequency distribution of survival times of defined groups of cancer deaths is lognormally distributed: larynx only (SLN), larynx and lung (TCR) and all cancers (ACC). All models each have three unknown parameters but it was possible to estimate a value for the lognormal parameter S a priori. By reduction to two unknown parameters the model stability has been improved. The material used to validate the methodology consisted of case histories of 965 patients, all treated during the period 1944-1968 by Dr Manuel Lederman of the Royal Marsden Hospital, London, with follow-up to 1988. This provided a follow-up range of 20-44 years and enabled predicted long-term survival fractions to be compared with the actual survival fractions, calculated by the Kaplan and Meier (1958 J. Am. Stat. Assoc. 53 457-82) method. The TCR and ACC models are better than the SLN model and for a maximum short-term follow-up of 6 years, the 20 and 25 year survival fractions could be predicted. Therefore the numbers of follow-up years saved are respectively 14 years and 19 years. Clinical trial results using the TCR and ACC models can thus be analysed much earlier than currently possible. Absolute cure from cancer was also studied, using not only the prediction models which incorporate a parameter for a statistically cured fraction of patients C(SLN), C(TCR) and C(ACC), but because of the long follow-up range of 20-44 years, also by complete life analysis. The survival experience of those who did not die of their original cancer of the larynx was compared to the expected survival experience of a population with the same age, birth cohort and sex structure. To date it has been generally assumed for early stage disease that although for some 5-10 years after treatment the survival experience of this patient subgroup might be no different from that expected in the matched group, thereafter the death rate of this subgroup becomes lower than that of the matched group. This implies that surviving cancer patients cured of their disease tend to die of other conditions at a higher than normal rate as they become older, and therefore cancer is never totally cured. Our conclusion is that at least for cancer of the glottic larynx, the answer to the question: 'Can cancer totally be cured?' is 'Yes to at least 15-years post-treatment and also probably to 25 years.'

HIV nephropathy and the Duffy antigen/receptor for Chemokines in African Americans.

BACKGROUND AND OBJECTIVES: HIV nephropathy (HIVAN) is markedly racially biased in its distribution, occurring in about 10% of HIV infected African Americans according to some studies. Based upon previous laboratory and epidemiological studies, the Duffy promoter polymorphism, which occurs almost exclusively in individuals of African descent, has been postulated to be the predisposing factor. We aimed to explore that relationship by directly genotyping individuals with HIV nephropathy to determine the proportion homozygous for this mutation to test the hypothesis it was responsible for the genetic component of this disease. We anticipated that if the polymorphism was associated with HIV nephropathy all individuals would be homozygous for this mutation. METHOD: Individuals with HIVAN proven on biopsy were identified from previous studies and a pre-existing clinical database. This diagnosis was confirmed by an experienced pathologist examining the biopsies in a blinded fashion. PCR and RFLP strategies were used on the biopsy samples to genotype for the Duffy promoter polymorphism. The cases were compared to a control population of HIV seronegative African Americans. RESULTS: Twenty African American individuals with HIV nephropathy were successfully genotyped. Only nine were homozygous for the promoter mutation. Nine were heterozygous and two homozygous wild type. Furthermore, the frequency of the polymorphism did not differ from the background rate in the African American population (OR = 0.788 95% confidence intervals 0.378-1.64). CONCLUSION: The Duffy promoter polymorphism was not disproportionately represented in persons with HIVAN calling into question any significant role in the pathogenesis of HIVAN.

Genotypic drug resistance and cause of death in HIV-infected persons who died in 1999.

We analyzed the relationship between viral drug resistance and causes of death in 29 HIV-1-infected patients who had been followed in an HIV-outpatient clinic and died in 1999. Six patients (21%) died with plasma HIV-RNA levels <1000 copies/ml. Seven (24%) died with wild-type (WT) virus in plasma, 6 (21%) had reverse transcriptase (RT) mutations only, 10 (34%) had multidrug-resistant (MDR) virus. The causes of death were not differently distributed among these groups; however, 8 of 16 patients (50%) with resistant viruses died of end-organ failure versus 2 of 7 patients (29%) with WT virus. Seventeen of 32 patients (53%) were thought by their physicians to be noncompliant with prescribed therapy. Major resistance mutations to antiretroviral drugs were present in viruses from at least 55% of our HIV-1-infected patients who died in 1999. Nonetheless, deaths also occurred among patients with well-controlled HIV infection and among patients with WT virus in plasma. Infections related to incomplete immune restoration, inability to maintain suppressive antiretroviral drug levels, and end-organ failures all contribute to mortalities in the era of highly active antiretroviral therapy.

Poor CD4 T cell restoration after suppression of HIV-1 replication may reflect lower thymic function.

OBJECTIVE: To characterize immune phenotype and thymic function in HIV-1-infected adults with excellent virologic and poor immunologic responses to highly active antiretroviral therapy (HAART). METHODS: Cross-sectional study of patients with CD4 T cell rises of > or = 200 x 10(6) cells/l (CD4 responders; n = 10) or < 100 x 10(6) cells/l (poor responders; n = 12) in the first year of therapy. RESULTS: Poor responders were older than CD4 responders (46 versus 38 years; P < 0.01) and, before HAART, had higher CD4 cell counts (170 versus 35 x 106 cells/l; P = 0.11) and CD8 cell counts (780 versus 536 x 10(6) cells/l; P = 0.02). After a median of 160 weeks of therapy, CD4 responders had more circulating naive phenotype (CD45+CD62L+) CD4 cells (227 versus 44 x 10(6) cells/l; P = 0.001) and naive phenotype CD8 cells (487 versus 174 x 10(6) cells/l; P = 0.004) than did poor responders (after 130 weeks). Computed tomographic scans showed minimal thymic tissue in 11/12 poor responders and abundant tissue in 7/10 responders (P = 0.006). Poor responders had fewer CD4 cells containing T cell receptor excision circles (TREC) compared with CD4 responders (2.12 versus 27.5 x 10(6) cells/l; P = 0.004) and had shorter telomeres in CD4 cells (3.8 versus 5.3 kb; P = 0.05). Metabolic labeling studies with deuterated glucose indicated that the lower frequency of TREC-containing lymphocytes in poor responders was not caused by accelerated proliferation kinetics. CONCLUSION: Poor CD4 T cell increases observed in some patients with good virologic response to HAART may be caused by failure of thymic T cell production.