Activation of infectious virus from latent human immunodeficiency virus infection of monocytes in vivo.

Individuals infected with HIV may be asymptomatic for years before progressing to overt AIDS. Since HIV can latently infect monocytoid cell lines, we examined whether HIV latency occurs in monocytes in vivo. Freshly isolated monocytes from asymptomatic seropositive individuals examined before and after culture were positive for HIV DNA, but not RNA, as measured by polymerase chain reaction, showing that HIV latency occurs in monocytes in vivo. Coculture of these latently infected monocytes with Con A-activated T cells from HIV-negative normal donors stimulated 90% of the patients' samples and latently infected THP-1 to produce infectious virus. Neither Con A, resting T cells, nor T cell supernatants induced virus. Plasma membranes from activated T cells stimulated HIV production, suggesting cell contact induces factor(s) in monocytes to overcome latency. Thus, monocytes in AIDS patients harbor latent HIV inducible during an immune response, leading to T cell infection and viral-induced pathology.

Clinical, virologic, and immunologic effects of combination therapy with ribavirin and isoprinosine in HIV-infected homosexual men.

We evaluated the clinical, immunologic, and virologic effects of oral treatment with ribavirin and isoprinosine for up to 3 months in asymptomatic, HIV-culture-positive homosexual men. Fifteen consecutive men received isoprinosine 4 g/day (1 g q.i.d.), and 800 (9 men) or 1,200 mg/day (6 men) of ribavirin. Five men in each ribavirin dosage group completed at least 2 months of treatment. No unexpected toxicities were observed. Eight minor HIV-related events occurred in six men while on study. All men remained HIV-positive, and time to positive culture decreased by at least 4 days in three men from each treatment group. Serum p24 levels did not change in two men who were p24 antigenemic and received 800 mg/day of ribavirin. Treatment was associated with a generalized lymphopenia affecting all lymphocyte subsets including CD4, which was partially reversible 1 month after stopping treatment. Most of the men remained anergic on DTHS skin testing. No improvements were noted in in vitro lymphoproliferative responses to antigens or in NK cell activity (which decreased significantly in the 1,200 mg/day ribavirin group). Although well tolerated at the doses employed, the combination of ribavirin and isoprinosine produced an unexpected generalized lymphopenia and did not exhibit HIV-suppressive or immunorestorative effects.

Treatment of HTLV-III/LAV-infected patients with D-penicillamine.

13 asymptomatic, HTLV-III/LAV-infected male homosexuals with generalized lymphadenopathy were treated with oral D-penicillamine. All patients had depressed T4/T8 ratios and 12 had impaired T-cell function. An escalating dose schedule was employed over 2-6 weeks with doses from 0.5 to 2 g/day. Generalized skin rashes developed in 4 patients which required discontinuation of therapy in one patient. Two patients developed mild transient elevations of hepatocellular enzymes. Reversible decreases in lymph node size, absolute lymphocyte counts, and T-cell lymphoproliferative responses were observed in the majority of patients without change in baseline T4/T8 ratios. All 10 patients treated for at least 2 weeks exhibited evidence for suppression of HTLV-III/LAV replication; complete inhibition of virus expression was seen in 60% of patients treated for 6 weeks. Three of the patients treated for 6 weeks remained culture negative for at least 6 weeks after stopping the drug. D-Penicillamine appears to be an effective drug for suppressing HTLV-III/LAV expression in vivo. Its potential role in the treatment of patients with the acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC) will require further evaluation.

Phase I/II trial of thymosin fraction 5 and thymosin alpha one in HTLV-III seropositive subjects.

Forty-two male homosexuals and/or hemophiliacs with depressed helper/suppressor T-cell ratios were treated with one of three different doses of thymosin fraction 5 (TF5, 30, 60, and 120 mg), or a single dose of thymosin Alpha One (TA1, 600 micrograms), by daily subcutaneous (SQ) administration for 10 weeks, followed twice weekly for 4 weeks. No major toxicity was noted for any of the preparations tested, although three subjects treated with TF5 had to discontinue therapy because of severe local skin reactions. Of the doses and preparations tested, only 60 mg TF5 was capable of significantly improving (p less than 0.02) mean T-cell lymphoproliferative responses to alloantigens (MLR) for six HTLV-III seropositive subjects who were abnormal prior to therapy. Peripheral blood lymphocytes from subjects treated with 60 mg TF5 also exhibited a transient restoration of mean mitogen-induced interleukin-2 (IL-2) production to normal. No effects were observed with any of the four treatment regimens on absolute helper T-cell numbers, NK activity, antibody titers to HTLV-III, or in the expression of a variety of surrogate markers for acquired immunodeficiency syndrome (AIDS). Four of the six seropositive subjects treated with 60 mg TF5 exhibited a return to depressed baseline MLR, after switching to twice weekly injections. With a median follow-up time of 20 months, six cases of AIDS developed. However, none of the five subjects whose MLR improved following treatment progressed to AIDS. We recommend daily subcutaneous (SQ) administration of 60 mg (40 mg/m2) TF5 for use in combined modality trials, along with drugs capable of suppressing replication of HTLV-III.