title: Human immunodeficiency virus type 2 (HIV-2) in Portugal: clinical spectrum, circulating subtypes, virus isolation, and plasma viral load.
abstract: The human immunodeficiency virus type 2 (HIV-2) is responsible for 4. 5% of AIDS cases in Portugal. Six HIV-2 subtypes have been described so far, subtype A being proposed as more pathogenic than the rest. The relationship between the clinical status and levels of both cellular and plasma HIV-2 viraemia is not well known, nor their modifications under antiretroviral therapy. Thirty-two consecutive HIV-2 infected persons (17 men, 15 women) attending two different hospitals in Lisbon in 1997 were enrolled prospectively in the study. All but 4 individuals most likely acquired the infection through heterosexual contact. More than half of the study population was of African origin, mainly from Guinea-Bissau. Eleven (34.4%) patients had developed clinical manifestations included within the B or C groups of the CDC classification system for HIV infection, with the rest being asymptomatic. Half of the population was undergoing antiretroviral treatment at the time of the study. HIV-2 subtypes were investigated using a new Nef-based restriction fragment length polymorphism (RFLP) method that allows differentiation of the main two variants, A and B. Plasma viral load was quantified using a new quantitative competitive reverse transcriptase polymerase chain reaction (QcRT-PCR) procedure as well as the Amp-RT assay. Virus isolation was attempted from peripheral blood mononuclear cells. All but one person carried HIV-2 subtype A. Plasma viraemia examined by QcRT-PCR was measurable in 15 (50%) of 30 subjects, yielding in all instances values below 20,000 HIV-2 RNA copies per ml. Plasma RT activity could be detected in only 10 (33%) of 30 subjects, a rate much lower than that seen in HIV-1 infection. Virus was isolated from 16 (53.3%) of 30 patients. A significant correlation was found between CD4+ counts, clinical status, rate of virus isolation, and plasma viral load by both QcRT-PCR and Amp-RT. In conclusion, HIV-2 subtype A is the predominant variant circulating in Portugal among both natives and immigrants. A lower cellular and plasma viral load with respect to HIV-1 was seen in persons without immunosuppression, from whom the rate of virus recovery was extremely low.
authors.affiliation: Service of Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain. vsoriano@dragonet.es
authors.forename: V
authors.initials: V
authors.lastname: Soriano
authors.forename: P
authors.initials: P
authors.lastname: Gomes
authors.forename: W
authors.initials: W
authors.lastname: Heneine
authors.forename: A
authors.initials: A
authors.lastname: Holguín
authors.forename: M
authors.initials: M
authors.lastname: Doruana
authors.forename: R
authors.initials: R
authors.lastname: Antunes
authors.forename: K
authors.initials: K
authors.lastname: Mansinho
authors.forename: W M
authors.initials: WM
authors.lastname: Switzer
authors.forename: C
authors.initials: C
authors.lastname: Araujo
authors.forename: V
authors.initials: V
authors.lastname: Shanmugam
authors.forename: H
authors.initials: H
authors.lastname: Lourenço
authors.forename: J
authors.initials: J
authors.lastname: González-Lahoz
authors.forename: F
authors.initials: F
authors.lastname: Antunes
mesh_terms: D005260:Female; D015693:Gene Products, nef / Q000032:analysis; D015498:HIV-2 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D011174:Portugal; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012703:Serotyping; D019562:Viral Load; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D015693:Gene Products, nef; D054311:nef Gene Products, Human Immunodeficiency Virus