Short-term safety and tolerability of didanosine combined with high- versus low-dose tenofovir disproxil fumarate in ambulatory HIV-1-infected persons.

Coadministration of didanosine (ddI) and tenofovir (TDF) results in increased ddI serum concentrations, which may lead to increased risk of ddI-associated toxicities. To evaluate the safety and tolerability of ddI/TDF, we performed a retrospective cohort analysis of patients seen in the HIV Outpatient Study, an ongoing dynamic cohort study of HIV-infected persons in clinical care. Study subjects were those who received at least 14 days of combined ddI/TDF before October 2003. Of 260 subjects who received ddI/TDF-based antiretroviral therapy, 155 (60%) received high-dose ddI (400 mg daily dose) and 105 (40%) received low-dose ddI (100-250 mg daily). Forty-two of the high-dose ddI recipients were later switched to low-dose ddI. The median time of observation for those on high-dose ddI only was 5 months, high-dose ddI switched to low-dose ddI was 16 months, and low-dose ddI only was 5 months (p < 0.05). Discontinuations because of toxicity were more frequent on high-dose ddI regimens (34/155, 22%) than on low-dose ddI regimens (9/105, 9%) (unadjusted odds ratio [OR(unadj)] 3.0, 95% confidence interval [95% CI] 1.30-7.09; p = 0.007). Among subjects without preexisting peripheral neuropathy, 12 (12%) of 101 subjects ever on high-dose ddI regimens had treatment-emergent peripheral neuropathy compared to 2 (4%) of 55 subjects on low-dose ddI regimens (OR(unadj) 3.57; 95% CI, 0.72-24.1; p = 0.14). Among patients without a history of pancreatitis, 6 (4%) of 153 subjects developed pancreatitis after starting high-dose ddI regimens, compared to none of the 103 subjects on low-dose ddI regimens (OR(adj) and 95% CIs undefined; p = 0.08). Severe laboratory abnormalities of creatinine, phosphorous, and bicarbonate were not different between the groups. A summary variable for any event--discontinuation for toxicity, treatment- emergent adverse event or abnormal laboratory values--indicated that 44 (28%) of 155 of those on high-dose ddI versus 13 (12%) of 105 on low-dose ddI developed any event (OR(unadj) 2.81; 95% CI, 1.36-5.86; p = 0.004). In conclusion, high-dose ddI/TDF-based therapy was more frequently associated with drug-related toxicity, adverse events, and treatment discontinuation than low-dose ddI/TDF regimens; low-dose ddI with TDF was generally well tolerated in these HIV-infected persons.

Prevalence and clinical correlates of HIV viremia ('blips') in patients with previous suppression below the limits of quantification.

OBJECTIVE: To examine the prevalence and clinical correlates of subsequently measurable viremia in HIV-infected patients who have achieved viral suppression below the limits of quantification (< 50 copies/ml). DESIGN: Non-randomized dynamic cohort study of ambulatory HIV patients in nine HIV clinics in eight cities. PATIENTS: Patients had two consecutive HIV-1 RNA levels < 50 copies/ml (minimum, 2 months apart) that were followed by at least two more viral level determinations while remaining on the same antiretroviral therapy (ART) between January 1997 and June 2000 (median 485 days). Transiently viremic patients were defined having a subsequently measurable viremia but again achieved suppression < 50 copies/ml. RESULTS: Of the 448 patients, 122 (27.2%) had transient viremia, 19 (4.2%) had lasting low-level viremia and 33 (7.4%) had lasting high-level viremia (defined as 50-400 and > 400 copies/ml, respectively). Only 16 (13.1%) of those who had transient viremia later had persistent viremia > 50 copies/ml. The occurrence of transient viremia did not vary with whether the patient was ART-naive or experienced (P = 0.31), or currently taking protease inhibitors or not (P = 0.08). On consistent ART, the median percentage increase in CD4 cell count was statistically different between subgroups of our cohort (Kruskal-Wallis, P = 0.002). CONCLUSIONS: Transiently detectable viremia, usually 50-400 copies/ml, was frequent among patients who had two consecutive HIV-1 RNA levels below the limits of quantification. In this analysis, such viremia did not appear to affect the risk of developing lasting viremia. Caution is warranted before considering a regimen as 'failing' and changing medications.

Influence of coinfection with hepatitis C virus on morbidity and mortality due to human immunodeficiency virus infection in the era of highly active antiretroviral therapy.

To ascertain the impact of hepatitis C virus (HCV) infection on human immunodeficiency virus (HIV) disease progression and associated death in the era of highly active antiretroviral therapy (HAART), we examined mortality rates, the presence of other diseases, and antiretroviral use in an observational cohort of 823 HIV-infected patients with and without HCV coinfection during the period of January 1996 through June 2001. Analyses were used to compare patient characteristics, comorbid conditions, and survival durations in HIV-infected and HIV-HCV-coinfected patients. HIV-HCV-coinfected persons did not have a statistically greater rate of acquired immunodeficiency syndrome or of renal or cardiovascular disease, but they did have more cases of cirrhosis and transaminase elevations. There were proportionately more deaths in the HIV-HCV-coinfected group. Age, baseline CD4+ cell count, and duration of HAART were significantly associated with survival, but HCV infection was not. HAART use was a strong predictor of increased duration of survival, suggesting that treatment is more important to survival than is HCV coinfection status.

Hepatitis A and B vaccination practices for ambulatory patients infected with HIV.

Few studies exist of adherence to guidelines for vaccination of persons infected with human immunodeficiency virus (HIV), especially in the era of highly active antiretroviral therapy (HAART). In a retrospective, cross-sectional analysis in the HIV Outpatient Study sites, 198 (32.4%) of 612 patients eligible for hepatitis B vaccine received at least 1 dose. In multivariate analysis, hepatitis B vaccination was associated with HIV risk category, education level, and number of visits to the HIV clinic per year. Among 716 patients eligible for hepatitis A vaccine, 167 (23.3%) received > or =1 dose. Response to hepatitis B vaccination was associated with higher nadir CD4+ cell counts (P=.008) and HIV RNA levels less than the level of detection (P=.04), although some response was documented at all CD4+ levels. Although there were low rates of complete hepatitis vaccination in this cohort of ambulatory patients, prompt efforts to vaccinate patients entering care, receipt of antiretroviral therapy, and practice reminder systems may enhance vaccination practices.

Disparities in prevalence of key chronic diseases by gender and race/ethnicity among antiretroviral-treated HIV-infected adults in the US.

BACKGROUND: Certain sociodemographic subgroups of HIV-infected patients may experience more chronic disease than others due to behavioural risk factors, advanced HIV disease or complications from extended use of combination antiretroviral therapy (cART), but recent comparative data are limited. METHODS: We studied HIV-infected adult patients in care during 2006-2010 who had been prescribed ≥ 6 months of cART. We analysed the prevalence of selected key chronic conditions and polymorbidity (having 2 or more out of 10 key conditions) by gender and race/ethnicity. RESULTS: Of the 3,166 HIV-infected patients (median age 47 years, CD4⁺ T-cell count 496 cells/mm³, duration of cART use 6.8 years), 21% were female, 57% were non-Hispanic White and over half were current or former tobacco smokers. The five most frequent conditions among women (median age 45 years) were dyslipidaemia (67.3%), hypertension (57.4%), obesity (31.7%), viral hepatitis B or C coinfection (29.0%) and low high-density lipoprotein cholesterol (HDLc; 27.3%). The five most frequent conditions in men (median age 47 years) were dyslipidaemia (81.2%), hypertension (54.4%), low HDLc (41.1%), elevated triglycerides (32.3%) and elevated non-HDLc (26.8%). In multivariable analyses, Hispanic patients had higher prevalence of obesity and diabetes than White patients; Black patients had higher prevalence of obesity and hypertension but lower rates of lipid abnormalities. Of all patients, 73.7% of women and 66.8% of men had polymorbidity, with no evidence of disparities by race/ethnicity. CONCLUSIONS: Among contemporary cART-treated HIV-infected adults, chronic conditions and polymorbidity were common, underscoring the importance of chronic disease prevention and management among ageing HIV-infected patients.

CD4 Cell Counts at HIV Diagnosis among HIV Outpatient Study Participants, 2000-2009.

Background. It is unclear if CD4 cell counts at HIV diagnosis have improved over a 10-year period of expanded HIV testing in the USA. Methods. We studied HOPS participants diagnosed with HIV infection ≤6 months prior to entry into care during 2000-2009. We assessed the correlates of CD4 count <200 cells/mm(3) at HIV diagnosis (late HIV diagnosis) by logistic regression. Results. Of 1,203 eligible patients, 936 (78%) had a CD4 count within 3 months after HIV diagnosis. Median CD4 count at HIV diagnosis was 299 cells/mm(3) and did not significantly improve over time (P = 0.13). Comparing periods 2000-2001 versus 2008-2009, respectively, 39% and 35% of patients had a late HIV diagnosis (P = 0.34). Independent correlates of late HIV diagnosis were having an HIV risk other than being MSM, age ≥35 years at diagnosis, and being of nonwhite race/ethnicity. Conclusions. There is need for routine universal HIV testing to reduce the frequency of late HIV diagnosis and increase opportunity for patient- and potentially population-level benefits associated with early antiretroviral treatment.

Increased mortality among publicly insured participants in the HIV Outpatient Study despite HAART treatment.

OBJECTIVE: Understanding mortality differences among HIV-infected patients can focus efforts to improve survival. DESIGN: We evaluated death rates, causes, and associated factors among treated patients in the HIV Outpatient Study (HOPS), a large, prospective, multicenter observational cohort of HIV-infected persons seen at a diverse set of US sites of care. METHODS: Among 3754 HOPS participants seen during 1996-2007 with at least 6 months of follow-up after initiating HAART and receiving HAART at least 75% of time under observation ('substantially treated'), we calculated hazard ratios for death using proportional hazards regression models. We also examined death causes and comorbidities among decedents. RESULTS: Substantially treated participants, followed a median 4.7 years (interquartile range, 2.2-8.5), experienced 331 deaths. In multivariable analyses, higher mortality was associated with an index CD4 cell count less than 200 cells/µl [adjusted hazard ratio (aHR), 2.86; 95% confidence interval (CI) 1.95-4.21], older age (aHR, 1.50 per 10 years; 95% CI 1.33-1.70), log(10)HIV RNA (aHR, 1.67 per log(10); 95% CI 1.51-1.85), but not race/ethnicity (aHR, 0.99 for blacks vs. whites, P = 0.92). Mortality was increased among publicly insured (PUB) vs. privately insured participants (PRV) when index CD4 cell count was at least 200 cells/µl (aHR, 2.03; 95% CI 1.32-3.14) but not when index CD4 cell count was less than 200 cells/µl (aHR, 1.3, P = 0.13). By death cause, PUB had significantly more cardiovascular events and hepatic disorders than PRV. Comorbidities more frequent among PUB vs. PRV decedents included cardiovascular disease, renal impairment, and chronic hepatitis. CONCLUSION: Among HAART-treated participants with CD4 cell counts at least 200 cells/µl, PUB experienced higher death rates than PRV. Non-AIDS death and disease causes predominated among publicly insured decedents, suggesting that treatable comorbidities contributed to survival disparities.

Changes in the use of HIV antiretroviral resistance testing in a large cohort of U.S. patients, 1999 to 2006.

INTRODUCTION: Monitoring antiretroviral (ARV) drug resistance is of growing importance in the management of persons infected with HIV, but few reports document how genotypic and phenotypic resistance testing (GPT) has been used among patients receiving routine outpatient care. METHODS: We studied data from participants in the HIV Outpatient Study seen at 10 HIV clinics in the United States during 1999 to 2006. We restricted analyses to patients whom we considered eligible for GPT (i.e., had a documented HIV viral load >1000 copies/mL). We used multivariable general modeling to evaluate temporal trends in use of GPT among eligible patients and to identify factors associated with being tested during 1999 to 2002 and 2003 to 2006. RESULTS: Of 5594 active patients, 3995 (71%) were considered eligible for GPT in at least one year during 1999 to 2006 (declining from 50.2% in 1999 to 31.2% in 2006). The fraction of eligible patients receiving GPT increased from 11.2% in 1999 to 31.0% in 2003 (P < 0.001 for trend) and then stabilized at approximately 30% through 2006. Among persons tested, the annual percentage receiving only genotype testing declined over time (90% to 56%), whereas the percentage receiving genotype and phenotype testing increased (5.4% to 39.1%). The annual use of GPT for ARV-naïve patients increased over time and after 2003 exceeded the corresponding rates for ARV-experienced patients. In multivariable analyses, low CD4 count and high HIV viral load were consistently associated with GPT. Compared with other ARV-experienced patients, those who were triple ARV-class experienced were consistently more likely to be tested, whereas ARV-naïve were less likely to be tested during 1999 to 2002 and more likely during 2003 to 2006. In addition, women and heterosexual men (vs. men who have sex with men) and black patients (vs. white) were less likely to be tested during 1999 to 2002, whereas older patients were less likely to be tested during 2003 to 2006. DISCUSSION: The annual frequency of GPT use has increased almost threefold since 1999. GPT use among ARV-naïve patients has increased coincident with dissemination of recommendations. Although earlier sex and racial/ethnic disparities in testing have waned, older patients were significantly less likely to be tested in recent years.

AIDS-defining opportunistic illnesses in US patients, 1994-2007: a cohort study.

OBJECTIVES: To assess the incidence and spectrum of AIDS-defining opportunistic illnesses in the highly active antiretroviral therapy (cART) era. DESIGN: A prospective cohort study of 8070 participants in the HIV Outpatient Study at 12 U.S. HIV clinics. METHODS: We calculated incidence rates per 1000 person-years of observation for the first opportunistic infection, first opportunistic malignancy, and first occurrence of each individual opportunistic illness during 1994-2007. Using stratified Poisson regression models, and adjusting for sex, race, and HIV risk category, we modeled annual percentage changes in opportunistic illness incidence rates by calendar period. RESULTS: Eight thousand and seventy patients (baseline median age 38 years; median CD4 cell count 298 cells/microl) experienced 2027 incident opportunistic illnesses during a median of 2.9 years of observation. During 1994-1997, 1998-2002, and 2003-2007, respectively, rates of opportunistic infections (per 1000 person-years) were 89.0, 25.2 and 13.3 and rates of opportunistic malignancies were 23.4, 5.8 and 3.0 (P for trend <0.001 for both). Opportunistic illness rate decreases were similar for the subset of patients receiving cART. During 2003-2007, there were no significant changes in annual rates of opportunistic infections or opportunistic malignancies; the leading opportunistic illnesses (rate per 1000 person-years) were esophageal candidiasis (5.2), Pneumocystis pneumonia (3.9), cervical cancer (3.5), Mycobacterium avium complex infection (2.5), and cytomegalovirus disease (1.8); 36% opportunistic illness events occurred at CD4 cell counts at least 200 cells/microl. CONCLUSIONS: Opportunistic illness rates declined precipitously after introduction of cART and stabilized at low levels during 2003-2007. In this contemporary cART era, a third of opportunistic illnesses were diagnosed at CD4 cell counts at least 200 cells/microl.

Rates of hospitalizations and associated diagnoses in a large multisite cohort of HIV patients in the United States, 1994-2005.

OBJECTIVES: To assess temporal trends in the rates of hospitalizations and associated diagnoses among HIV-infected patients before and during the era of highly active antiretroviral therapy. DESIGN: A prospective cohort study of 7155 patients enrolled in the HIV Outpatient Study at 10 US HIV clinics. METHODS: We evaluated rates of hospitalizations for major categories of medical conditions during 1994-2005 and modeled trends in these rates using multivariable Poisson regression models for repeated observations. We assessed patient characteristics associated with hospitalization using multiple logistic regression. RESULTS: The rates of hospitalizations (per 100 person-years) fell from 24.6 in 1994 to 11.8 in 2005 (P < 0.0001). The rates of hospitalizations for AIDS opportunistic infections decreased from 7.6 in 1994-1996 to 1.0 in 2003-2005 (P < 0.0001). AIDS opportunistic infections were present at 31% of hospitalizations in 1994-1996 versus 9.5% in 2003-2005, and chronic end-organ disease conditions were present at 7.2% of such hospitalizations in 1994-1996 versus 14.3% in 2003-2005. Mean CD4+ cell count at hospitalization increased from 115 cells/mul in 1994 to 310 cells/mul in 2005. Factors independently associated with hospitalization in the highly active antiretroviral therapy era (1997-2005) included older age, history of substance abuse, lower CD4+ cell count, history of AIDS, and public health insurance. CONCLUSION: The rates of hospitalizations for HIV-infected patients declined substantially during 1994-2005, due mainly to reductions in the AIDS opportunistic infections. Compared with the period 1994-1997, patients in the highly active antiretroviral therapy era were hospitalized with higher CD4+ cell counts and more frequently for chronic end-organ conditions.

Renal function in Tenofovir-exposed and Tenofovir-unexposed patients receiving highly active antiretroviral therapy in the HIV Outpatient Study.

BACKGROUND: Cases of renal dysfunction have been reported in HIV-infected patients taking tenofovir (TDF), but few large studies have examined population-level changes in renal function associated with TDF use in patients in routine care. METHODS: The authors analyzed data from participants in the HIV Outpatient Study (HOPS) who had normal baseline renal function and received >1 month of TDF-containing (n = 593) or TDF-sparing (n = 521) HAART after November 1, 2001. RESULTS: Median baseline CrCl estimated by Cockcroft-Gault equation was 106 mL/min for TDF-exposed and 110 mL/min for TDF-unexposed patients (P = 0.06). In multivariable analyses, 1-year changes in CrCl (mL/min) from baseline were -5.7 among TDF-exposed and 2.6 among TDF-unexposed (P < 0.001). Incident renal disease was diagnosed in 7 TDF-exposed and 3 TDF-unexposed patients. CONCLUSIONS: In this large cohort of HIV-infected outpatients, use of TDF-containing HAART was associated with modest decreases in CrCl during the first year, but not with frequent, clinically significant renal toxicity.

Increased body mass index does not alter response to initial highly active antiretroviral therapy in HIV-1-infected patients.

BACKGROUND: Body mass index (BMI) can influence drug metabolism, thus affecting efficacy and risk for toxicities. Hypothesizing that persons with an increased BMI and larger volumes of distribution may experience a suboptimal response to highly active antiretroviral therapy (HAART), we evaluated the effect of BMI on virologic and immunologic response in previously ART-naive patients initiating therapy. METHODS: Using data from the HIV Outpatient Study, we analyzed the statistical association of BMI and other selected demographic variables with achieving an undetectable viral load and experiencing a CD4 cell count increase of more than 100 cell/microL after 3 to 9 months of therapy among antiretroviral-naive patients initiating HAART. RESULTS: Among 711 patients included in analysis, 43% had a BMI of more than 25 (overweight-obese). Higher BMI was associated with being female, having black or Hispanic race/ethnicity, being heterosexual, and using injection drugs (all P<0.001). The patients in BMI groups did not differ significantly by baseline CD4 cell count or the duration of the initial HAART regimen. Although median baseline viral loads were significantly lower in obese participants (P=0.008), overweight or obese BMI did not significantly alter the likelihood of achieving an undetectable viral load and a CD4 cell count increase of more than 100 cells/microL compared with normal weight persons. CONCLUSION: A substantial proportion of HIV-infected outpatients in this cohort were overweight or obese. Increased BMI was not associated with decreased virologic and immunologic responses to initial HAART. Responses were equivalent and within expected ranges between normal weight patients, overweight patients, and obese patients at 3 to 9 months of observation.

Mortality in the highly active antiretroviral therapy era: changing causes of death and disease in the HIV outpatient study.

BACKGROUND: AIDS-related death and disease rates have declined in the highly active antiretroviral therapy (HAART) era and remain low; however, current causes of death in HAART-treated patients remain ill defined. OBJECTIVE: To describe mortality trends and causes of death among HIV-infected patients in the HAART era. DESIGN: Prospective, multicenter, observational cohort study of participants in the HIV Outpatient Study who were treated from January 1996 through December 2004. MEASUREMENTS: Rates of death, opportunistic disease, and other non-AIDS-defining illnesses (NADIs) determined to be primary or secondary causes of death. RESULTS: Among 6945 HIV-infected patients followed for a median of 39.2 months, death rates fell from 7.0 deaths/100 person-years of observation in 1996 to 1.3 deaths/100 person-years in 2004 (P=0.008 for trend). Deaths that included AIDS-related causes decreased from 3.79/100 person-years in 1996 to 0.32/100 person-years in 2004 (P=0.008). Proportional increases in deaths involving liver disease, bacteremia/sepsis, gastrointestinal disease, non-AIDS malignancies, and renal disease also occurred (P=or<0.001, 0.017, 0.006, <0.001, and 0.037, respectively.) Hepatic disease was the only reported cause of death for which absolute rates increased over time, albeit not significantly, from 0.09/100 person-years in 1996 to 0.16/100 person-years in 2004 (P=0.10). The percentage of deaths due exclusively to NADI rose from 13.1% in 1996 to 42.5% in 2004 (P<0.001 for trend), the most frequent of which were cardiovascular, hepatic, and pulmonary disease, and non-AIDS malignancies in 2004. Mean CD4 cell counts closest to death (n=486 deaths) increased from 59 cells/microL in 1996 to 287 cells/microL in 2004 (P<0.001 for trend). Patients dying of NADI causes were more HAART experienced and initiated HAART at higher CD4 cell counts than those who died with AIDS (34.5% vs 16.8%, respectively, received HAART for 4 of more years, P<0.0001; 22.4% vs 7.8%, respectively, initiated HAART with CD4 cell counts of more than 350 cells/microL, P<0.001). CONCLUSIONS: Although overall death rates remained low through 2004, the proportion of deaths attributable to non-AIDS diseases increased and prominently included hepatic, cardiovascular, and pulmonary diseases, as well as non-AIDS malignancies. Longer time spent receiving HAART and higher CD4 cell counts at HAART initiation were associated with death from non-AIDS causes. CD4 cell count at time of death increased over time.