Eva Operskalski

The seroepidemiology of human herpesvirus 8 (Kaposi's sarcoma-associated herpesvirus) : distribution of infection in KS risk groups and evidence for sexual transmission

Striking differences in Kaposis sarcoma (KS) risk for AIDS patients who acquire HIV via homosexual activity and those whose HIV infections derive from blood product exposure suggest the presence of a sexually transmitted agent other than HIV in the development of KS. Using an immunofluorescence assay, we examined serum samples from 913 patients for the presence of antibody specific for infection by human herpesvirus 8 (HHV8), an agent whose genome is regularly found in KS tissue. The distribution of HHV8 seropositivity conforms to that expected for a sexually transmitted pathogen and tracks closely with the risk for KS development. Our data support the inference that this virus is the etiologic cofactor predicted by the epidemiology of KS.

Effects of CCR5-Delta32, CCR2-64I, and SDF-1 3'A alleles on HIV-1 disease progression: An international meta-analysis of individual-patient data

The burgeoning information on the human genome creates opportunities and challenges for studies of disease associations. Because genetic differences often produce modest effects, many patients must be studied to reach definitive conclusions. In the absence of a single large study, meta-analysis of individual-patient data (13) from smaller studies offers a way to assemble an adequate sample size. This approach is based on a unifying protocol that has standardized analytic definitions. When the protocol is applied to data contributed by most investigators working in a field, this method can provide more convincing results than a simple pooling of data or a meta-analysis of published reports (3). A meta-analysis of individual-patient data is also superior to a meta-analysis of published reports for examining differences in reported results. Host genetic variability affects the risk for AIDS after infection with HIV-1, but the effect of specific alleles (that is, alternative forms of a gene that exist at a specific chromosomal location [locus]) has been inconsistent. C-C chemokine receptor 5 (CCR5) is a major co-receptor for HIV-1, but CCR5- 32, an allele that contains a 32base pair deletion, codes for a nonfunctional co-receptor (46). CCR5-32 homozygotes (people who inherited the CCR5-32 allele from both parents) are highly resistant to HIV-1 infection (47). CCR5-32 heterozygotes (people who inherited the CCR5-32 allele from one parent and a functional CCR5 allele from the other parent) are susceptible to HIV-1 infection; however, according to some reports (6, 820), they progress from HIV-1 infection to AIDS more slowly than persons with two normal CCR5 alleles (called wild-type individuals). CCR2b is a minor HIV-1 co-receptor. The gene that codes for this chemokine receptor has a variant allele (CCR2-64I) that may affect the risk for AIDS (21). Epidemiologic studies of CCR2-64I carriers have been inconsistent (1826), and in vitro studies have identified no functional differences between cells from CCR2-64I carriers and those from wild-type patients (27, 28). Stromal cellderived factor-1 (SDF-1) is the chemokine ligand of CXCR4, an important co-receptor for HIV-1 late in the disease course (29, 30). Homozygosity for the SDF-1 3A allele has been reported to slow disease progression (31), but not in all studies (18, 19, 3235). To address these inconsistencies, we conducted an international meta-analysis of individual-patient data on the CCR5, CCR2, and SDF-1 alleles; data were contributed by 19 teams of investigators. Methods Organization of the Meta-Analysis All research teams investigating associations of genetic alleles with the course of HIV-1 disease progression were invited to contribute individual-patient data to the International Meta-Analysis of HIV Host Genetics. Collaborating teams were identified through MEDLINE searches, cited references of retrieved papers, abstracts of major HIV-related meetings, and communication with investigators working in the field. The meta-analysis was also announced in Nature Medicine (36), on the Web site of the International Cochrane Collaboration, and at HIV scientific meetings. A common protocol was developed in collaboration with research teams identified through these efforts. The meta-analysis database remained open until 12 February 1999 for the collection of CCR5- 32 and CCR2-64I data; because most of the participating investigator teams evaluated SDF-1 3A after they studied CCR5-32 and CCR2-64I, we collected data on SDF-1 3A until 30 November 1999. Selection of Databases Prospective cohort studies of patients with HIV-1 infection were included in the analysis if they had collected information on the pertinent genotypes, as well as on the time from seroconversion or study entry to the development of AIDS and to death. We excluded studies if genetic data or time-to-event data were unavailable or if the participants were enrolled after 1 January 1996. We included casecontrol studies if they compared patients with rapid versus slower rates of progression. Casecontrol studies were analyzed separately from prospective cohort studies. Definitions and End Points The prospective cohort studies in our meta-analysis typically had follow-up visits every 6 months. Within each study, we divided the participants according to enrollment before (seroconverters) or after (seroprevalent patients) HIV-1 infection. For seroconverters, a negative result and a subsequent positive result on enzyme-linked immunosorbent assay (ELISA) and Western blot test were obtained after enrollment. We analyzed the data on a time scale that originated at the date of study entry for seroprevalent participants and at the estimated date of seroconversion (calculated as the midpoint between the last study visit at which the patient tested negative for HIV-1 and the first visit at which the patient tested positive for HIV-1) for the seroconverters. The cohorts differed little in the precision of the estimated date of seroconversion because semiannual data were typically available. Data for patients of European descent and data for patients of African descent (37) were considered separately. Our analysis examined four major outcomes: 1) time from seroconversion (or study entry) to the development of AIDS, according to 1987 criteria by the U.S. Centers for Disease Control and Prevention [38]; 2) time from seroconversion [or study entry] to death; 3) time from development of AIDS to death; and 4) serum or plasma HIV-1 RNA level, which was measured by using a consistent method within each study. For seroconverters, we used the first measurement of HIV-1 RNA level recorded since onset of chronic HIV-1 infection (range, 6 to 42 months after the estimated date of seroconversion); for seroprevalent patients, we used the first study measurement of HIV-1 RNA level. We censored data on follow-up after 1 January 1996 to minimize the effects of potent antiretroviral therapy. The average follow-up to AIDS development or to the point of censoring in the CCR5- 32 and CCR2-64I analyses was 6.73 years for seroconverters and 6.37 years for seroprevalent patients; for the SDF-1 analysis, the average follow-up was 7.14 years for the seroconverters and 6.51 years for seroprevalent patients. We specified our outcome variables a priori and asked all investigators to contribute data in a format consistent with the protocol. Investigators at the coordinating center, which was located at the National Cancer Institute in Rockville, Maryland, communicated with the contributing investigators to verify that the data from each study adhered to the common definitions of the meta-analysis. The contributed data sets also underwent logical tests to identify internal inconsistencies or incompatibilities. Any missing information or errors in logic that were identified at the coordinating center were referred to the contributing investigators; all identified errors were resolved. Statistical Analysis We used Cox regression to determine hazard ratios (relative hazards) for the times to events for all study cohorts and subgroups (39). The hazard ratio approximates the relative risk or incidence risk ratio. A log10 transformation was used for all analyses of HIV-1 RNA level. Differences in HIV-1 RNA level within studies were analyzed as differences for independent samples of continuous variables. Pooled summary estimates of hazard ratios and differences of means were obtained by weighting estimates from each study by the inverse of its variance (1, 40). We estimated fixed effects and random effects (1, 40). Fixed-effects models assume that any differences in results among studies are simply due to chance, whereas random-effects models assume that there may be true differences in the results of different studies. We report random-effects estimates because these provide more conservative confidence intervals when the results are highly heterogeneous across cohorts. (In the absence of heterogeneity, fixed-effects and random-effects estimates coincide.) We assessed heterogeneity by using the Q statistic, which we considered to be significant if the P value was less than 0.10 (1). However, some cohorts had few SDF-1 3A homozygotes with clinical events. Therefore, we also calculated an efficient score test for heterogeneity on the basis of the appropriate interaction terms between genotype and cohort in a cohort-stratified proportional hazards model. Inferences were similar with both tests. To model the effect of rare genotypes (CCR2-64I homozygotes or patients who were heterozygous for CCR5- 32 and CCR2-64I), we fit Cox models to the pooled data from all cohort studies with stratification by study. For cohorts with no events among SDF-1 3A homozygotes, we estimated log relative hazards values on the basis of a penalized likelihood with a penalty term of 0.5 (log[1 + exp ()] ). Penalty terms shrink extreme values (which also have large variances) toward zero. Because these extreme estimates have small weights, they contribute little to the overall results. Their exclusion yielded results similar to those of the main analysis. All calculations were performed by using the MATLAB software package, version 5.3 (The MathWorks, Inc., Natick, Massachusetts). Results We restricted the main analysis of CCR5- 32 and CCR2-64I to patients of European or African descent with genotype data for both alleles (Table 1). Because CCR5- 32 and CCR2-64I are in complete linkage of disequilibrium (nonrandom association of alleles that lie close together on a chromosome) (21), the CCR5- 32 and CCR2-64I alleles are never found on the same paternal or maternal chromosome. Therefore, we compared patients with a variant allele to patients who were wild-type homozygotes for both CCR5 and CCR2. Because the CCR5- 32 allele is almost exclusively found in persons of European descent (46), the analysis of CCR5-32 was limited to such persons. The analysis of SDF-1 3A was limited to persons

HIV/HCV Co-infection: Pathogenesis, Clinical Complications, Treatment, and New Therapeutic Technologies

World-wide, hepatitis C virus (HCV) accounts for approximately 130 million chronic infections, with an overall 3% prevalence. Four to 5 million persons are co-infected with HIV. It is well established that HIV has a negative impact on the natural history of HCV, including a higher rate of viral persistence, increased viral load, and more rapid progression to fibrosis, end-stage liver disease, and death. Whether HCV has a negative impact on HIV disease progression continues to be debated. However, following the introduction of effective combination antiretroviral therapy, the survival of coinfected individuals has significantly improved and HCV-associated diseases have emerged as the most important co-morbidities. In this review, we summarize the newest studies regarding the pathogenesis of HIV/HCV coinfection, including effects of coinfection on HIV disease progression, HCV-associated liver disease, the immune system, kidney and cardiovascular disease, and neurologic status; and effectiveness of current anti-HIV and HCV therapies and proposed new treatment strategies.

Infection with Human Immunodeficiency Virus Type 1 (HIV-1) among Recipients of Antibody-Positive Blood Donations

OBJECTIVE To assess the incidence of human immunodeficiency virus type 1(HIV-1) transmission by antibody (anti-HIV-1)-positive blood components, and to determine the immunologic and clinical course in HIV-1-infected recipients. DESIGN AND SUBJECTS We retrospectively tested approximately 200,000 donor blood component specimens stored in late 1984 and 1985 for anti-HIV-1, and we contacted recipients of positive specimens to determine their serologic status. They were compared with both recipients of HIV-1-negative transfusions and healthy (untransfused) controls. Subjects were seen at 3- to 6-month intervals for up to 4 years for clinical and immunologic evaluations. MEASUREMENTS AND MAIN RESULTS Of 133 recipients, 9 had other possible exposures. Excluding these cases, 111 of 124 (89.5%) were anti-HIV-1-positive (95% CI, 84.1% to 94.5%). The recipients sex, age, underlying condition, and type of component did not influence infection rates. The cumulative risk for developing the acquired immunodeficiency syndrome (AIDS) within 38 months after transfusion was 13% (CI, 7.5% to 21.6%). At 36 +/- 3 months after the index transfusion, seropositive recipients had lower counts of CD2+CDw26+, CD4+, CD4+CD29+, and CD4+CD45RA+subsets and more CD8+I2+ lymphocytes than did recipients of anti-HIV-1-negative transfusions. The CD4+ and CD2+CDw26+subsets changed the most rapidly. The absolute CD8+ count remained normal. CONCLUSIONS Transfusion of anti-HIV-1-positive blood infected 90% of recipients. The rate of progression to AIDS within the first 38 months after infection was similar to that reported for homosexual men and hemophiliacs. Although most lymphocyte subset counts changed over time, CD8+ counts were constant.

Transfusion transmission of retroviruses: human T-lymphotropic virus types I and II compared with human immunodeficiency virus type 1.

Background: The incidence of transfusion transmission of human T‐ lymphotropic virus type I (HTLV‐I) and HTLV type II (HTLV‐II) has not been compared directly or to that of human immunodeficiency virus type 1 (HIV‐1). The effects of refrigerator storage of the blood component on infectivity of the viruses needs definition.

Leukocyte immunophenotyping by flow cytometry in a multisite study: Standardization, quality control, and normal values in the Transfusion Safety Study

The Transfusion Safety Study (TSS) is a multicenter, cooperative investigation of factors that may determine the occurrence and modify the expression of transfusion-transmitted infections. A flow cytometry laboratory was established in each of the six participating centers in order to avoid alterations in cell phenotypes which may be caused by shipping delays, temperature changes, and handling. As a consequence, in order to assure compatibility of results, stringent standardization, quality control, and proficiency testing procedures were developed. This paper documents (i) the effect of time from phlebotomy to specimen staining and then to analysis for the antibodies used in the study; (ii) the effects of variations in light scatter cursor location for certain antibodies; (iii) a quality control program and data management and analysis system, each specifically designed for the study; and (iv) presents extensive data on age- and sex-related reference (normal) ranges for the several individual and paired monoclonal antibodies used in the study. Problems encountered, including obtaining reliable absolute lymphocyte counts, interference by nucleated erythrocytes, and sources of variability in results, are discussed. This study is meant to serve as a reference for future TSS publications.

A 32-bp Deletion within the CCR5 Locus Protects against Transmission of Parenterally Acquired Human Immunodeficiency Virus but Does Not Affect Progression to AIDS-Defining Illness

The beta-chemokine receptor CCR5 is required as a coreceptor by non-syncytium-inducing (NSI) strains of human immunodeficiency virus type 1 (HIV-1). NSI viruses predominate early during an infection and are thought to be important for the transmission of HIV-1. The importance of CCR5 during parenteral transmission of HIV-1 was investigated. The distribution of the homozygous deleted CCR5 genotype among 566 exposed persons with hemophilia and 97 exposed transfusion recipients indicated that the lack of CCR5 expression protected persons from infection. This suggests that the initial predominance of NSI viruses during an infection does not result from limited availability of CXCR4-expressing cells within the mucosa but rather implies a more fundamental requisite for CCR5-expressing cells early during an infection regardless of the route of transmission. In addition, no difference in the rate of progression to AIDS (CDC 1987 definition) of infected heterozygous compared with homozygous wild type subjects was observed.

Activation of CD8 T Cells Predicts Progression of HIV Infection in Women Coinfected with Hepatitis C Virus

BACKGROUND Because activation of T cells is associated with human immunodeficiency virus (HIV) pathogenesis, CD4 and CD8 activation levels in patients coinfected with HIV and hepatitis C virus (HCV) may explain conflicting reports regarding effects of HCV on HIV disease progression. METHODS Kaplan-Meier and multivariate Cox regression models were used to study the risk of incident clinical AIDS and AIDS-related deaths among 813 HCV-negative women with HIV infection, 87 HCV-positive nonviremic women with HIV coinfection, and 407 HCV-positive viremic women with HIV coinfection (median follow-up time, 5.2 years). For 592 women, the percentages of activated CD4 and CD8 T cells expressing HLA-DR (DR) and/or CD38 were evaluated. RESULTS HCV-positive viremic women had a statistically significantly higher percentage of activated CD8 T cells (P < .001) and a statistically significantly higher incidence of AIDS compared with HCV-negative women (P < .001 [log-rank test]). The AIDS risk was greater among HCV-positive viremic women in the highest tertile compared with the lowest tertile (>43% vs <26%) of CD8(+)CD38(+)DR(+) T cells (hazard ratio, 2.94 [95% confidence interval, 1.50-5.77]; P = .001). This difference was not observed in the HCV-negative women (hazard ratio, 1.87 [95% confidence interval, 0.80-4.35]; P = .16). In contrast, CD4 activation predicted AIDS in both groups similarly. Increased percentages of CD8(+)CD38(-)DR(+), CD4(+)CD38(-)DR(-), and CD8(+)CD38(-)DR(-) T cells were associated with a >60% decreased risk of AIDS for HCV-positive viremic women and HCV-negative women. CONCLUSION HCV-positive viremic women with HIV coinfection who have high levels of T cell activation may have increased risk of AIDS. Earlier treatment of HIV and HCV infection may be beneficial.

Negative-Strand Hepatitis C Virus (HCV) RNA in Peripheral Blood Mononuclear Cells from Anti-HCV–Positive/HIV-Infected Women

BACKGROUND Hepatitis C virus (HCV) has been reported to replicate in peripheral blood mononuclear cells (PBMCs), particularly in patients coinfected with HCV and human immunodeficiency virus (HIV). However, there are limited data regarding the prevalence of and the factors associated with extrahepatic replication. METHODS The presence of negative-strand HCV RNA in PBMCs was evaluated by a strand-specific assay for 144 anti-HCV-positive/HIV-infected women enrolled in the Womens Interagency HIV Study. One to 5 PBMC samples obtained from each woman were tested. Multivariate analyses were used to assess for associations with the clinical and demographic characteristics of the women. RESULTS Negative-strand HCV RNA was detected in 78 (25%) of 315 specimens, and, for 61 women (42%), > or = 1 specimen was found to have positive results. The presence of negative-strand HCV RNA in PBMCs was significantly positively associated with an HCV RNA plasma level of > or = 6.75 log copies/mL (P=.04) and consumption of > or = 7 alcoholic drinks per week (P=.02). It was also negatively associated with injection drug use occurring in the past 6 months (P=.03). A negative association with a CD4+ CD38+ DR+ cell percentage of > 10% and a positive association with acquired immunodeficiency syndrome were borderline significant (P=.05). CONCLUSIONS HCV replication in PBMCs is common among HIV-coinfected women and appears to be a dynamic process related to lifestyle, virologic, and immunologic factors.

Correlates of perinatal depression in HIV-infected women.

Maternal perinatal depression (PND) may interfere with effective perinatal HIV care. In order to begin examining the prevalence and characteristics of PND in HIV-infected women, we analyzed data from the medical records of all HIV-infected women who had received perinatal care in the Maternal-Child and Adolescent Center for Infectious Diseases and Virology at LAC/USC Medical Center from 1997 through 2006. Data from 273 individual women (328 live births) were analyzed. Demographic, medical history, psychosocial, pregnancy related, and HIV-related factors measured during the perinatal period were examined for an association with PND using multivariate logistic regression with generalized estimating equations to account for the within subject correlation due to multiple births per mother. The overall prevalence of PND was 30.8%. Multivariate analysis showed that PND was significantly associated with substance abuse during pregnancy (odds ratio [OR] = 2.81, 95% confidence interval [CI]: 1.35-5.82) and past history of psychiatric illness (OR = 3.72, 95% CI: 2.06-6.71). Compared to mothers with CD4 nadir greater than 500 cells/mm3, mothers with a CD4 nadir during pregnancy #200 cells=mm3 were 3.1 times more likely to experience PND (OR = 3.01, 95% CI: 1.32-6.88). Women who had antiretroviral (ARV) medications adherence problems during pregnancy were more likely to experience PND than women who were adherent (OR = 2.14, 95% CI: 1.08-4.23). These preliminary results suggest that rates of PND among HIV-infected women are substantial. We conclude that pregnant HIV-infected women should be routinely screened for PND. Prospective studies examining the bio-psycho-social markers of PND in HIV-infected women are indicated.