The elevation of circulating platelets after IFN-alpha therapy in HIV-1 seropositive thrombocytopenic patients correlates with increased plasma levels of IL-6.
In this study we evaluated the effect of recombinant interferon-alpha 2b (IFN-alpha 2b) therapy on the number of circulating platelets and interleukin-6 (IL-6) plasma levels in 12 human immunodeficiency virus type 1 (HIV-1) seropositive patients, affected by a severe and persistent thrombocytopenia. The levels of IL-6 in plasma of HIV-1 seropositive thrombocytopenic subjects before IFN-alpha therapy were similar (80 +/- 15 pg/ml) to those observed in 15 HIV-1 seropositive asymptomatic individuals (75 +/- 12 pg/ml) and 30 HIV-1 seronegative blood donors (59.5 +/- 25 pg/ml). On the other hand, IL-6 amounts (148 +/- 36 pg/ml) in plasma of HIV-1 seropositive thrombocytopenic subjects were significantly (p < 0.01) increased after 5 weeks of IFN-alpha 2b therapy, showing a good correlation (p < 0.05, chi-square test) with the levels of circulating platelets. Moreover, an increased spontaneous IL-6 production by peripheral blood monocytes was observed after IFN-alpha 2b therapy in HIV-1 seropositive thrombocytopenic patients. Our results suggest that an increased production of IL-6, one of the main factors controlling thrombocytopoiesis, may partially explain the ability of IFN-alpha 2b therapy, to restore platelet production in a subset of HIV-1 seropositive thrombocytopenic individuals.
Zauli
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Institute of Microbiology, L. and A. Seragnoli, University of Bologna, Italy.
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MC
Gugliotta
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Furlini
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La Placa
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D000328:Adult; D001792:Blood Platelets / Q000187:drug effects* / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D016655:HIV Core Protein p24 / Q000097:blood; D006679:HIV Seropositivity / Q000097:blood* / Q000150:complications / Q000276:immunology; D015497:HIV-1; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology / Q000627:therapeutic use*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D009000:Monocytes / Q000276:immunology; D010976:Platelet Count; D011994:Recombinant Proteins; D013921:Thrombocytopenia / Q000097:blood / Q000150:complications / Q000188:drug therapy* / Q000276:immunology
D016655:HIV Core Protein p24; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D015850:Interleukin-6; D011994:Recombinant Proteins