HIV-associated metabolic and morphologic abnormality syndrome. Welcome therapy may have unwelcome effects.

Metabolic and morphologic complications of HAART are probably caused by several interrelated and complex physiologic processes that are just beginning to be understood. Whether there is validity to the current theories regarding mitochondrial toxicity of NRTIs, lipid pathway interruptions of protease inhibitors, or the host immune response itself as the primary culprit remains to be seen. In the interim, physicians should use great caution and be circumspect in their judgment with regard to "quick-fix" treatments of these complications. Furthermore, scientifically unsupported decisions about switching antiretroviral agents in an attempt to alleviate a particular toxic effect may place the patient at risk for antiretroviral-therapy failure. Formal adoption of a case definition of HAMMAS remains a priority for the scientific community, because anecdotal observations compiled to date do not yet constitute a discrete syndrome. A clear case definition, possibly modeled after criteria for defining rheumatic diseases, will greatly facilitate properly designed research trials to elucidate causes and possible treatments of this troublesome syndrome.