Human immunodeficiency virus type 2 (HIV-2) in Portugal: Clinical spectrum, circulating subtypes, virus isolation, and plasma viral load

• Published in: Journal of medical virology 2000-05, Vol.61 (1), p.111-116
• Main Authors: Soriano, Vincent, Gomes, Perpétua, Heneine, Walid, Holguín, Africa, Doruana, Manuela, Antunes, Rute, Mansinho, Kamal, Switzer, William M., Araujo, Carlos, Shanmugam, Vedapuri, Lourenço, Helena, González-Lahoz, Juan, Antunes, Francisco
• Format: Article
• Language: English
• Subjects: AIDS/HIV; Biological and medical sciences; Epidemiology; Female; Fundamental and applied biological sciences. Psychology; Gene Products, nef - analysis; HIV-2; HIV-2 - classification; HIV-2 - genetics; HIV-2 - isolation & purification; Human viral diseases; Humans; Infectious diseases; Male; Medical sciences; Microbiology; Middle Aged; nef Gene Products, Human Immunodeficiency Virus; Polymorphism, Restriction Fragment Length; Portugal; Prospective Studies; Reverse Transcriptase Polymerase Chain Reaction; Serotyping; subtypes; viraemia; Viral diseases; Viral diseases of the genital and urinary system; Viral Load; Virology
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/(SICI)1096-9071(200005)61:1<111::AID-JMV18>3.0.CO;2-W

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. J. Med. Virol. 61:111–116, 2000. © 2000 Wiley‐Liss, Inc.