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Session 94 Poster Session Osteopenia/Osteoporosis Session Time: 4:30-6:30 pm Room 4E-F

712-T. Immunologic and Virologic Correlates of Bone Pathologies in HIV-Infection J. Fessel*1, L. Hurley2, S. Follansbee1, and D. Klein3 Kaiser Permanente Med. Care Prog., 1San Francisco, CA; 2Oakland, CA; and 3Hayward, CA Background: Osteonecrosis (ON) and osteoporosis (OP) occur excessively in HIV infection. We investigated the immunologic and virologic correlates of these bone pathologies in HIV infection. Others have reported CD4+ cell levels (/mm3) in ON that seem disproportionately low vis-à-vis HIV RNA (log10/mL). CD4+ cell levels of 124 have been seen with HIV RNA of 4.1 in patients with ON; their control patients without ON had CD4+ cell levels that were 71% higher at 212 with HIV RNA 15% higher at 4.7. CD4+ cells have been reported 270 in patients with ON but 26% higher at 341 in those without ON; yet HIV RNAs were identical at 3.1. 23 ON patients in another study had CD4 of 150 but HIV RNA of only 3.3 including 26% with undetectable viral load. Methods. 3859 HIV-positive men studied over 30 monoths included 50 cases with either ON or OP-fractures (vertebrae, hips, or wrists) and 3809 controls without those bone pathologies. CD4+ cell and HIV RNA data were from 6 months before or 3 months after either the X-ray diagnosis in cases or an arbitrary, uniform date October 1, 1999 in controls. Data used were closest to the X-ray diagnosis in cases or the arbitrary date in controls. Bone density studies made in 30 of the HIV-positive men were analyzed for T-scores in lumbar spine and hip. Results were analyzed by chi2 or Fisher Exact with 1-sided p values. Results. HIV RNA <1.7 log together with CD4+ cells <200 were seen in 10% of the ON and fracture cases but in only 4.6% of controls (p =0.035). HIV RNA <1.7 log together with CD4+ cells <350 occurred in 32% of the ON and fracture cases but in only 20.5% of controls (p = 0.025). HIV RNA <1.7 log together with CD4+ cells <350 occurred in 3/5 (60%) with bone density T scores <-2.5; in 6/16 (37.5%) with T scores >-2.5 to <-1.0; but in only 1/9 (11.1%) with T scores >-1.0 (p = 0.08). Conclusions. More often than expected, HIV-positive patients with bone disease have CD4+ cell levels that are low vis-a-vis plasma viral load. This observation might provide insight into the cause of bone pathology in some HIV positive patients. A possible explanation meriting investigation is sequestration of HIV in osteocytes with release of HIV gp120 into bone marrow, causing CD4+ cell apoptosis.

©2002 9th Conference on Retroviruses and Opportunistic Infections