Monocytes harbour replication-competent, non-latent HIV-1 in patients on highly active antiretroviral therapy.

OBJECTIVE: To determine whether HIV-1 can be recovered from blood monocytes as well as resting, memory CD4 T lymphocytes of patients on highly active antiretroviral therapy (HAART) with undetectable plasma viraemia and whether infection is active or latent. DESIGN: Five patients with plasma HIV-1-RNA levels of less than 500 copies/ml for at least 3 months and less than 50 copies/ml at the time of sampling were initially selected, followed by an additional five patients with viral loads of less than 50 copies/ml for 3 months or more. METHODS: Monocytes were isolated from blood by plastic adherence, then further purified by a second adherence step or CD3 depletion before co-culture with CD8-depleted donor peripheral blood mononuclear cells. Virus isolates were examined for mutations conferring resistance to reverse transcriptase or protease inhibitors and for genotype. The highly purified monocytes were also analysed for the presence of proviral and unintegrated viral DNA and multiply spliced (MS) viral mRNA by polymerase chain reaction. RESULTS: Virus was recovered from monocytes of five patients. Sequencing of the recovered viruses did not reveal multiple drug resistance, and was consistent with a non-syncytium-inducing/CCR5 phenotype. Proviral DNA was detectable in monocytes from all subjects, and unintegrated HIV-1 DNA and MS RNA was found in four out of five populations examined. CONCLUSION: Recovery of replication-competent virus from some HAART patients indicates that monocytes can also harbour HIV-1. Detection of circular, viral DNA and spliced RNA, albeit at very low levels, in these cells suggests that their infection is recent and transcriptionally active rather than latent.

Viral hepatitis in Nigeria--sickle-cell disease and commercial blood donors.

Hepatitis virus infection is a major cause of morbidity and mortality in sub-Saharan Africa. The high prevalence of hepatitis B virus (HBV) infection in this region is thought to be due to horizontal transmission during childhood. Hepatitis C virus (HCV) infection is also quite prevalent in Africa, but the epidemiology of this infection has yet to be defined. We examined the prevalence of HBV and HCV serological markers in 220 patients attending sickle-cell anaemia clinics in Benin City, Nigeria, in 228 healthy locals, and in 104 local commercial blood donors, to test the hypothesis that patients requiring blood transfusion from unscreened commercial blood donors (in this area of high prevalence for viral hepatitis) are at great risk for the acquisition of post-transfusion hepatitis. Overall, the frequency of hepatitis viraemia in blood donors was high (14% of donors were either HbsAg or anti-HCV positive). Evidence of previous exposure to HBV was common in all three study groups. Risk of HBV infection for sickle-cell patients was not clearly increased by blood transfusion. HCV exposure, however, appears related to transfusion requirement, and all Western-blot-confirmed anti-HCV-positive sicklers had a history of blood transfusion. Screening of blood products in sub-Saharan Africa is unlikely to reduce prevalence of HBV, but may minimize the risks of HCV transmission.