Serologic testing for human immunodeficiency virus antibodies

Familiarity with available serologic tests for antibodies to human immunodeficiency virus (HIV) has become increasingly important in a wide variety of clinical settings. Enzyme-linked immunosorbent assay (ELISA) commercial kits are most often used as Enzyme-linked immunosorbent assay (ELISA) commercial kits are most often used as screening tests, and Western blot techniques are used for confirmation of positive results. ELISA specificity and sensitivity exceed 98%; the predictive value of a positive test varies from 2% for a weakly positive test in a low-prevalence population to 99% for a strongly positive test in a high-risk group. Confirmatory Western blot testing identifies antibodies with affinity for specific HIV antigens. Indeterminate Western blot antibody patterns necessitate subsequent testing or alternative methods for interpretation. A "window" period of up to 3 or more months follows acute HIV infection before seropositivity occurs.     

Serologic testing of human immunodeficiency virus infection

This article describes laboratory methods available for testing serum to determine whether a patient is infected with human immunodeficiency virus (HIV). Included is discussion of uses and limitations of the assays, patient counseling, laboratory safety, and interpretation of the test results.     

Therapy of human immunodeficiency virus infections

Although therapy is currently available for many of the infections and neoplastic complications of AIDS, there is no effective therapy for the underlying immunodeficiency state. The authors review various attempts at treatment to date, and conclude that a major decrease in HIV-associated morbidity will require a combined approach, making use of our knowledge of the epidemiology, as well as the molecular and cellular biology, of the virus.     

The staging and monitoring by primary care providers of patients with human immunodeficiency virus infections

As HIV testing expands through the population, primary care physicians will become more involved in the testing process. They will also be caring for increasingly larger numbers of HIV infected people from the asymptomatic through those with AIDS, through hospice care, should that become appropriate. This article summarizes key areas of clinician support for the HIV infected, clinical and laboratory markers associated with rapid progression of the disease, and important problem areas in clinical management. It also presents a series of staging diagrams that have proven useful in assisting clinicians in educating patients about the natural history of the HIV infection, the rationale for staging, the rationale for the timing of AZT therapy and Pneumocystis prophylactic treatment, and the significance of various prognosticators in management as the disease progresses.     

Molecular-based laboratory testing and monitoring for human immunodeficiency virus infections.

Applications of laboratory testing for human immunodeficiency virus type 1 (HIV-1) infection have made significant impact on clinical care of HIV-infected patients globally. As these technologies continue to evolve and new technologies emerge, unique and highly sensitive nucleic acid-based testing methods will offer more and better means for us to guide physicians in anti-retroviral treatment strategies and clinical management of HIV infected patients. In this review we discuss a variety of current molecular-based methods that are available for HIV testing including diagnosis, monitoring disease progression, and detection of drug resistance to anti-retroviral therapy. Newer approaches that could be used in future HIV testing are also introduced.     

Antiviral agents for non-human immunodeficiency virus infections

Several new agents for treating viral infections have been developed in recent years. All available agents are virustatic, inhibiting specific steps in the process of viral replication. No agent is active against nonreplicating or latent viruses. Acyclovir is useful in the treatment of genital herpes, herpes simplex encephalitis, mucocutaneous herpetic infection, varicella infection in the immunosuppressed host, and herpes zoster infection in the normal and the immunosuppressed host. It can also be used for prevention of herpesvirus infection in immunocompromised patients. Ganciclovir is indicated for the treatment of cytomegalovirus retinitis in patients with the acquired immunodeficiency syndrome and is effective in the treatment and prevention of cytomegalovirus infection in other immunocompromised patients. Famciclovir and valacyclovir are effective in the management of herpes simplex and varicella-zoster infection. Amantadine and rimantadine are useful therapeutically and prophylactically in the management of influenza A virus infection. Chronic hepatitis B infection can respond to lamivudine therapy, and the optimal treatment of hepatitis C is the combination of interferon alfa and ribavirin. Despite pronounced toxic effects, foscarnet and cidofovir are effective antiviral agents in specific settings.     

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND: This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T- lymphotropic virus via the transfusion of seronegative, infectious window-period blood. STUDY DESIGN AND METHODS: Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window- period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window- period donations is the number of post-screening HIV-infectious donations removed by STS. RESULTS: Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window- period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million. CONCLUSION: STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.     

Medication adherence feedback intervention predicts improved human immunodeficiency virus clinical markers

Thirty‐three participants in a human immunodeficiency virus (HIV) medication adherence feedback (MAF) intervention were compared with 58 HIV‐positive non‐participants in laboratory‐tested CD4 and viral load. The intervention provided adherence feedback and counselling based on a visual display from an electronic pill bottle (MEMS^TM). Multiple regression controlling for baseline CD4 and showed that postintervention CD4 was higher for MAF participants than for non‐MAF participants. Non‐MAF participants' CD4 significantly declined over time. MAF participants were also less likely than non‐MAF participants to have a detectable postintervention viral load.     

人类免疫缺陷病毒感染与丙型肝炎病毒感染相互影响的研究

目的 探讨人类免疫缺陷病毒(HIV)感染与丙型肝炎病毒(HCV)感染的相互影响.方法 选取180例经输血或曾有偿献血而感染HIV/AIDS的患者为研究对象,同时选取50例本院同期诊治的HCV感染者为HCV组,50例本院健康体检者设为对照组.分析各组肝脏生化功能、CD4+和CD8+细胞计数及β2-微球蛋白(β2-MG)等指标变化.结果 180例HIV感染患者中,合并HCV感染率为89.4％,ALT、AST、A/G与HA各指标在HIV+ HCV组、HIV、HCV及对照组的差异均有统计学意义;CD4+、CD8+的细胞计数与β2-MG在各组有显著统计学差异(P＜0.01).结论 经输血或曾有偿献血而感染HIV的患者HCV感染率较高,HIV/HCV混合感染可能加重肝功能损伤,加速肝纤维化及肝硬化进程.     

Surveillance for human immunodeficiency virus type 1 group O infections in the United States

BACKGROUND: Reports that the human immunodeficiency virus type 1 (HIV- 1) group O variants are not reliably detected by some commercial diagnostic tests have raised concerns about the sensitivity of existing screening tests, especially with regard to blood safety. Although it is unlikely that these divergent strains are prevalent in North America, systematic, continuous surveillance is needed to monitor the potential spread of HIV variants into that region. STUDY DESIGN AND METHODS: Stored serum samples (n = 1072) from both high- and low-risk population groups at several sites in the United States and Puerto Rico were tested by peptide enzyme immunoassays specific for the prototypic HIV-1 group O strains, MVP5180 and ANT70. RESULTS: None of the 1072 samples examined had peptide reactivity that was consistent with HIV-1 group O infection. CONCLUSION: While no evidence of specific HIV-1 group O (MVP5180 or ANT70) infection was found in this study, the sensitivity of current tests has not been fully evaluated against the wide range of genetic variation of HIV. Therefore, it is important to continue active surveillance for HIV-1 and HIV type 2 strains, to characterize any divergent strains, and to judiciously modify tests to correct for any deficiencies in sensitivity.     

CT manifestations of human immunodeficiency virus (HIV)-related pulmonary infections

The infectious pulmonary complications of acquired immunodeficiency syndrome (AIDS) are reviewed, with emphasis on the spectrum of CT imaging findings and diagnostic accuracy and limitations as reported in the current literature. Changes in epidemiologic trends for common AIDS-related infections and the associated ranges of CD4 lymphocyte counts, when these infections are typically encountered, are discussed.     

Primary human immunodeficiency virus

The term "primary HIV infection" refers to the period from initial infection with the human immunodeficiency virus to complete seroconversion. It is a period of extreme infectiousness. The occurrence and severity of symptoms during primary HIV infection correlate with the rapidity of clinical and immunologic decline. Treatment of patients during primary infection may improve immune preservation and reconstitution. In this review article, we present information that will help clinicians understand, recognize, and diagnose primary HIV infection. The current approach to management of primary HIV infection is based more on expert opinion than clinical trial results, though ongoing clinical trials should provide more information about this syndrome.     

Prevalence of hepatitis B virus, delta agent and human immunodeficiency virus infections in drug addicts

Infections with the hepatitis B (HBV) and delta (HDV) viruses and with the human immunodeficiency virus (HIV) are very common among intravenous drug addicts. The serum of 80 percent of drug addicts contains one of the HBV markers, and 15 percent of them carry an anti-D antibody. Infections with the hepatitis A and non A-non B viruses are also very common among drug abusers. Some of them may harbour several of these pathogens. This can explain the frequency of liver disease (biological anomalies and histological lesions) observed in drug addicts, as does alcohol consumption associated with drug abuse. Fifty to 60 per cent of intravenous drug addicts are seropositive for HIV. This prevalence varies across studies and countries. The high prevalence of infection by HIV in drug addicts may be explained by the use of a shared syringe. This prevalence exposes drug addicts to an increase in AIDS cases in the near future. The high prevalence of infections by HBV, HDV and HIV in drug addicts represents a risk factor for the spread of HBV, HDV and HIV infections among the general population. Preventing the rapid spread of these viruses among drug addicts is of utmost importance for the future.     

Residual risk of transfusion-transmitted human immunodeficiency virus, hepatitis C virus, and hepatitis B virus infections in Italy

BACKGROUND: Estimating the risk of transfusion-transmitted infections (TTIs) is essential for monitoring blood safety. The residual risk of TTI was estimated for nearly 90 percent of the blood supply in Italy. STUDY DESIGN AND METHODS: Data were analyzed from 1,079,281 repeat donors, corresponding to 5,361,000 donations made in blood transfusion centers throughout Italy in the period 1999 through 2001. The residual risk of transfusion-transmitted human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections was estimated with the incidence rate-window period model. The denominator for the incidence rate (i.e., the number of person-years at risk) was estimated on a sample of 5850 donors. RESULTS: The risk of an infectious donation entering the blood supply, per 1 million donations, was 1.91 (probable range, 0.52-3.32) for HIV, 16.74 (9.57-24.01) for HCV, and 69.16 (43.12-102.70) for total HBV (adjusted for vaccination and hepatitis B surface antigen transience). CONCLUSION: In Italy, the estimated residual risk of TTI is apparently low, particularly for HIV infection. Although the estimated risks are higher for HCV and HBV, the introduction of mandatory viral detection tests for HCV in 2002 should account for an 80 percent reduction in the HCV risk. Moreover, the ongoing HBV vaccination program will contribute to reducing the risk of transfusion-transmitted HBV.