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Biomedical subjects

Philip Keiser

Publications and source records attributed to Philip Keiser.

8 recordsLinked to original sources
PubMed2006

Multicenter evaluation of the Bayer ADVIA Centaur HIV 1/O/2 enhanced (EHIV) assay.

BACKGROUND: It is important that serological assays detect antibodies to human immunodeficiency virus (HIV) in all infected individuals, including those infected with less prevalent, more diverse subtypes. METHODS: Performance of the ADVIA Centaur HIV 1/O/2 Enhanced (EHIV) Assay was tested on 1344 samples from HIV-positive subjects, 6061 samples from groups at low-risk for HIV infection, and 1042 samples from groups at high-risk for HIV-1 and HIV-2 infection. Results were compared with those of an FDA-approved predicate assay. RESULTS: The ADVIA Centaur EHIV Assay showed good precision with a diagnostic specificity of 99.9% and diagnostic sensitivity of 100%. HIV seroconversion was detected earlier in 6 panels, at the same time in 13 panels and later in only 1 of the panels when compared to the predicate assay, thereby narrowing the window period between infection and antibody detection. Of clinical significance, a blood donor sample that was indeterminate by HIV-1 Western blot and non-reactive by the predicate assay was repeatedly reactive in the ADVIA Centaur Assay and confirmed as positive by HIV-2 immunoblot. CONCLUSIONS: The ADVIA Centaur EHIV Assay is useful as an aid in the diagnosis of individuals infected with HIV-1 and/or HIV-2.

AIDS Serodiagnosis↗
PubMed2005

Racial and gender disparities in receipt of highly active antiretroviral therapy persist in a multistate sample of HIV patients in 2001.

BACKGROUND: National data from the mid-1990s demonstrated that many eligible patients did not receive highly active antiretroviral therapy (HAART) and that racial and gender disparities existed in HAART receipt. We examined whether demographic disparities in the use of HAART persist in 2001 and if outpatient care is associated with HAART utilization. METHODS: Demographic, clinical, and pharmacy utilization data were collected from 10 US HIV primary care sites in the HIV Research Network (HIVRN). Using multivariate logistic regression, we examined demographic and clinical differences associated with receipt of HAART and the association of outpatient utilization with HAART. RESULTS: In our cohort in 2001, 84% of patients received HAART and 66% had 4 or more outpatient visits during calendar year (CY) 2001. Of those with 2 or more CD4 counts below 350 cells/mm in 2001, 91% received HAART; 82% of those with 1 CD4 test result below 350 cells/mm received HAART; and 77% of those with no CD4 counts below 350 cells/mm received HAART. Adjusting for care site in multivariate analyses, age >40 years (adjusted odds ratio [AOR] = 1.13), male gender (AOR = 1.23), Medicaid coverage (AOR = 1.16), Medicare coverage (AOR = 1.73), having 1 or more CD4 counts less than 350 cells/mm (AOR = 1.33), and having 4 or more outpatient visits in a year (OR = 1.34) were significantly associated with an increased likelihood of HAART. African Americans (odds ratio [OR] = 0.84) and those with an injection drug use risk factor (OR = 0.86) were less likely to receive HAART. CONCLUSIONS: Although the overall prevalence of HAART has increased since the mid-1990s, demographic disparities in HAART receipt persist. Our results support attempts to increase access to care and frequency of outpatient visits for underutilizing groups as well as increased efforts to reduce persistent disparities in women, African Americans, and injection drug users (IDUs).

Adolescent↗
PubMed2005

Hospital and outpatient health services utilization among HIV-infected adults in care 2000-2002.

BACKGROUND: Rapid changes in HIV epidemiology and antiretroviral therapy may have resulted in recent changes in patterns of healthcare utilization. OBJECTIVE: The objective of this study was to examine sociodemographic and clinical correlates of inpatient and outpatient HIV-related health service utilization in a multistate sample of patients with HIV. DESIGN: Demographic, clinical, and resource utilization data were collected from medical records for 2000, 2001, and 2002. SETTING: This study was conducted at 11 U.S. HIV primary and specialty care sites in different geographic regions. PATIENTS: In each year, HIV-positive patients with at least one CD4 count and any use of inpatient, outpatient, or emergency room services. Sample sizes were 13,392 in 2000, 15,211 in 2001, and 14,403 in 2002. MAIN OUTCOME MEASURES: Main outcome measures were number of hospital admissions, total days in hospital, and number of outpatient clinic/office visits per year. Inpatient and outpatient costs were estimated by applying unit costs to numbers of inpatient days and outpatient visits. RESULTS: Mean numbers of admissions per person per year decreased from 2000 (0.40) to 2002 (0.35), but this difference was not significant in multivariate analyses. Hospitalization rates were significantly higher among patients with greater immunosuppression, women, blacks, patients who acquired HIV through drug use, those 50 years of age and over, and those with Medicaid or Medicare. Mean annual outpatient visits decreased significantly between 2000 and 2002, from 6.06 to 5.66 visits per person per year. Whites, Hispanics, those 30 years of age and over, those on highly active antiretroviral therapy (HAART), and those with Medicaid or Medicare had significantly higher outpatient utilization. Inpatient costs per patient per month (PPPM) were estimated to be 514 dollars in 2000, 472 dollars in 2001, and 424 dollars in 2002; outpatient costs PPPM were estimated at 108 dollars in 2000, 100 dollars in 2001, and 101 dollars in 2002. CONCLUSION: Changes in utilization over this 3-year period, although statistically significant in some cases, were not substantial. Hospitalization rates remain relatively high among minority or disadvantaged groups, suggesting persistent disparities in care. Combined inpatient and outpatient costs for patients on HAART were not significantly lower than for patients not on HAART.

AIDS-Related Opportunistic Infections↗
PubMed2003

Comparison of symptoms of influenza A with abacavir-associated hypersensitivity reaction.

Differentiation between abacavir hypersensitivity and viral respiratory infections is problematic. Fifteen cases of abacavir hypersensitivity were matched to 30 controls with culture proven influenza A with no abacavir exposure. Rash was associated with hypersensitivity (odds ratio [OR] = 13.1, P = 0.02) as was the presence of nausea (OR = 30, P < 0.001), vomiting (OR = 17.1, P = 0.001) or diarrhoea (OR = 22, P < 0.001). The number of gastrointestinal symptoms was also predictive of hypersensitivity reaction (P < 0.001). Respiratory symptoms (cough, sore throat, or dyspnoea) were not associated with abacavir hypersensitivity (OR = 0.08, P = 0.001). Multivariate analysis confirmed the following associations for abacavir hypersensitivity: the number of gastrointestinal symptoms (OR = 8.6, P = 0.0032), cough (OR = 0.039, P = 0.02) and rash (OR = 16.9, P = 0.07). Abacavir hypersensitivity is strongly associated with gastrointestinal (GI) symptoms. Cough without GI symptoms is associated with influenza.

Anti-HIV Agents↗
PubMed2002

An anti-CD45RO immunotoxin kills latently infected human immunodeficiency virus (HIV) CD4 T cells in the blood of HIV-positive persons.

Highly active antiretroviral therapy has decreased the morbidity and mortality of human immunodeficiency virus (HIV) infection, but latently infected cells remain for prolonged periods. CD4(+) CD45RO(+) T cells are a major latent virus reservoir in HIV-infected persons. Replication-competent, latently HIV-infected T cells can be generated in vitro by infecting peripheral blood mononuclear cells with HIV and then eliminating the HIV-producing cells with an anti-CD25 immunotoxin (IT). The CD25(-) latently infected cells then can be eliminated with an anti-CD45RO IT. This study determined whether this IT also could kill latently infected CD4 T cells from HIV-infected persons with or without detectable plasma viremia. The results show that ex vivo treatment of cells from HIV-positive persons by anti-CD45RO IT reduces the frequency of both productively and latently infected cells. In contrast, CD4(+) CD45RA(+) naive T cells and a proportion of CD4(+) CD45RO(lo) memory T cells are spared.

Antiretroviral Therapy, Highly Active↗
PubMed2002

Trizivir.

Treatment of HIV infection has typically been carried out using two nucleoside analogues and a protease inhibitor (PI). Such regimens can be complex and have high pill burdens. Use of alternative regimens, such as triple nucleoside based regimens, can improve adherence and decrease toxicities associated with PI therapy. Trizivir is a combination tablet of zidovudine, lamivudine and abacavir. This formulation allows a dosing schedule of one pill twice-daily. The components of have performed favourably compared to PI-based regimens, such as indinavir. However, in one study the individual components of Trizivir did not suppress HIV-1 viral replication as well as the PI-based regimen in a subset of patients with very high HIV-1 plasma RNA. Trizivir also avoids side effects of antiretroviral therapy, such as hyperlipidaemia, but its use is associated with a hypersensitivity reaction in a small number of patients. Trizivir is an important part of the HIV armamentarium. The potency and ease of administration of Trizivir make it worth consideration in HIV therapy, either by itself or in combination with other agents.

Antiretroviral Therapy, Highly Active↗
PubMedDate not supplied

Comparison of nevirapine- and efavirenz-containing antiretroviral regimens in antiretroviral-naïve patients: a cohort study.

OBJECTIVE: Efavirenz (EFV) was superior to nevirapine (NVP) in two recent cohort studies; but data from clinical trials suggest that three studies are needed to validate cohort results. We performed a cohort analysis comparing time to treatment failure and change in plasma HIV-1 RNA from baseline in antiretroviral therapy (ART)-naïve individuals treated with NVP- or EFV-containing regimens. METHOD: A cohort analysis of three observational databases (N = >10,000 patients) found 1,078 ART-naïve individuals treated with NVP-containing (n = 523) or EFV-containing (n = 555) regimens. Patients were evenly matched and received at least three antiretroviral agents. The primary endpoint was time to treatment failure defined as a rebound in plasma HIV-1 RNA > 400 copies/mL. Other endpoints were change in plasma HIV-1 RNA from baseline and percent with plasma HIV-1 RNA <400 copies/mL over time. Potential confounding variables were analyzed using the Cox proportional hazards model. RESULTS: Compared to EFV, NVP patients had a shorter time to treatment failure (307 days vs. 589 days; p <.001), less decrease in plasma HIV-1 RNA (-0.51 log vs. -1.32 log; p <.001), and fewer patients with plasma HIV-1 RNA < 400 copies/ mL (45% vs. 51%; p <.001). Significant factors for failure were baseline CD4 count (per 100 cell increase) or viral load (per log increase), treatment center, and year of entry (p <.05 for all comparisons). Race, gender, and background nucleoside use were insignificant factors. Multivariate analysis that included significant factors for failure demonstrated improved relative hazard with EFV compared to NVP (odds ratio = 0.50, p <.001). CONCLUSION: EFV-containing antiretroviral regimens were associated with superior clinical outcome, as measured by time to treatment failure. Results are commensurate with other large cohort studies comparing EFV and NVP.

Adult↗