HAART side effect no. 237 -- drum roll, please! -- let's give a warm welcome to...shingles. In a June American Journal of Medicine study, researchers at a Barcelona hospital found that 24 of 316 HIVers (8 percent) on a cocktail of two NRTIs and one or more protease inhibitor developed, within their first four months of pill-popping, nasty nerve-burning outbreaks of shingles, a.k.a. the herpes-zoster virus (not herpes simplex, the genital or cold-sore variety).

Why did these unlucky 24 get itchy, painful shingles? Researchers can only speculate, although they have identified what might be a specific pre-breakout signal: a dramatic boost in CD8 cells, which the shingles group had in spades, compared with those sans shingles. According to Pere Domingo, MD, a principal investigator in the study, "A sudden increase in CD8 cells may prompt a defensive response in the immune system that the individual was not able to mount." In other words, the herpes outbreak, however hellish, may be a sign that a rebooted immune system is up and doing its job once again. Hey, thanks!

John Mazzullo, MD, of New England Medical Center agrees, noting that these shingles flare-ups jibe with the occasional, though seemingly inappropriate, appearance of CMV, MAC and other infections in HIVers whose HAART-powered immune systems have started fighting back: "A profoundly immune-deficient person can't mount an appropriate immune response to viral infections like shingles, but often after starting HAART, a disease will appear -- the result of the body trying to rid itself of the pathogen."

Larger studies would be needed to discover why some HAART-HIVers get shingles -- and how to prevent them -- though it may be premature to start phone-zapping Pharma. A handful of the nation's leading HIV docs told POZ that they've seen little incidence of shingles among new HAARTers. Boston doc Cal Cohen, MD, research director at the Community Research Initiative New England, says the study's shingles-CD8 link "may be a good one, but shingles might not follow a CD8 jump often enough to justify changing therapy. One option would be to start [an antiviral like] acyclovir as a preventive."

Too bad this tip came too late for the Barcelona HIVers, who'd gladly have traded their shingles for vinyl siding.