Items in AFP with MESH term: RNA, Viral
ABSTRACT: The polymerase chain reaction assay, branched DNA assay and nucleic acid sequence-based amplification assay quantitate human immunodeficiency virus (HIV) RNA levels. Plasma viral load (PVL) testing has become a cornerstone of HIV disease management. Initiation of antiretroviral drug therapy is usually recommended when the PVL is 10,000 to 30,000 copies per mL or when CD4+ T-lymphocyte counts are less than 350 to 500 per mm3 (0.35 to 0.50 x 10(9) per L). PVL levels usually show a 1- to 2-log reduction within four to six weeks after therapy is started. The goal is no detectable virus in 16 to 24 weeks. Periodic monitoring of PVL is important to promptly identify treatment failure. When feasible, the same assay should be used for serial PVL testing in the individual patient. At least two PVL measurements usually should be performed before antiretroviral drug therapy is initiated or changed. PVL testing may be helpful in the rare instance of indeterminate HIV antibody testing, especially in a patient with recent infection.
ABSTRACT: The primary goal of antiretroviral therapy for human immunodeficiency virus (HIV) infection is suppression of viral replication. Evidence indicates that the optimal way to achieve this goal is by initiating combination therapy with two or more antiretroviral agents. The agents now licensed in the United States for use in combination therapy include five nucleoside analog reverse transcriptase inhibitors (zidovudine, didanosine, zalcitabine, stavudine and lamivudine), two nonnucleoside reverse transcriptase inhibitors (delavirdine and nevirapine) and four protease inhibitors (saquinavir, ritonavir, indinavir and nelfinavir). Current recommendations suggest that antiretroviral therapy be considered in any patient with a viral load higher than 5,000 to 20,000 copies per mL, regardless of the CD4+ count. Selection of the combination regimen must take into account the patient's prior history of antiretroviral use, the side effects of these agents and drug-drug interactions that occur among these agents and with other drugs as well. Because of the potential for viral resistance, nonnucleoside reverse transcriptase inhibitors and protease inhibitors should only be used in combination therapy. Antiretroviral agents are rapidly being developed and approved, so physicians must make increasingly complex treatment decisions about medications with which they may be unfamiliar.
ABSTRACT: Hepatitis C, which is caused by the hepatitis C virus (HCV), is a major public health problem in the United States. HCV is most efficiently transmitted through large or repeated percutaneous exposures to blood. Most patients with acute HCV infection develop persistent infection, and 70 percent of patients develop chronic hepatitis. HCV-associated chronic liver disease results in 8,000 to 10,000 deaths per year, and the annual costs of acute and chronic hepatitis C exceed $600 million. An estimated 3.9 million Americans are currently infected with HCV, but most of these persons are asymptomatic and do not know they are infected. To identify them, primary health care professionals should obtain a history of high-risk practices associated with the transmission of HCV and other bloodborne pathogens from all patients. Routine testing is currently recommended only in patients who are most likely to be infected with HCV.
Confronted by an Unexpected Laboratory Result - Curbside Consultation
Challenges of Improving Adherence to HIV Therapy - Editorials
CDC Issues New Recommendations for the Prevention and Control of Hepatitis C Virus Infection - Special Medical Reports
The Conundrum of Early HIV Infection - Editorials