638   Avascular Necrosis of the Hip (Leggs-Calve-Perthes Disease [LCPD]) in HIV-Infected Children in Long-Term Follow-Up: PACTG Study 219.

Avascular Necrosis of the Hip (Leggs-Calve-Perthes Disease [LCPD]) in HIV-Infected Children in Long-Term Follow-Up: PACTG Study 219. D. M. Gaughan¹, L. M. Mofeson*², M. D. Hughes¹, G. R. Seage¹, and J. M. Oleske³for the PACTG 219 Team.
¹Harvard Sch. of Publ. Hlth., Boston, MA;²NICHD/NIH, Bethesda, MD; and³UMDNJ, Newark, NJ.

Background:Avascular necrosis of the hip has been reported in HIV-infected adults. Whether this is an HIV-related complication or an adverse effect of treatment is unknown. We examined LCPD incidence in HIV-infected children.

Methods:PACTG protocol 219 is a long-term study to examine outcomes in HIV-infected children and in children born to HIV-infected women and exposed to HIV and antiretroviral treatment. Children who have enrolled in PACTG are given examinations (minimum yearly) with collection of clinical and laboratory data. The database was reviewed for reports of LCPD and other bone disorders for all children on study as of 1/1/96 (allowing at least 4 years of follow-up through 2000).

Results:1,011 HIV-infected children were enrolled prior to 1/1/96. Two prevalent cases of LCPD were reported at study entry (a male Caucasian age 8 yrs. and a female Hispanic age 4 yrs.). Three children were diagnosed with LCPD during follow-up, representing three cases per 3,197 person-years (PY) of observation and an incidence rate in this cohort of 94 per 100,000 PY (95% CI, 19—274). This is significantly higher than the incidence of LCPD in the general population (about 6 per 100,000 PY). The median age of onset for the incident cases was 9 yrs. (range 4—15 yrs.); all were perinatally infected. Two were male, one was female; two were Hispanic and one was Caucasian. At study entry, all children had received nucleoside reverse transcriptase inhibitors, including ZDV. Although all children reported current or prior exposure to a protease inhibitor by 1999, 2/3 of the incident cases were not receiving protease inhibitors at the time of diagnosis.

Conclusions:Similar to HIV-infected adults, HIV-infected children appear to have an increased risk for avascular necrosis of the hip. The etiology of this phenomenon requires further evaluation.