We describe clinical features, body fat distribution, and prevalence of metabolic abnormalities in 35 patients with acquired partial lipodystrophy (APL) seen by us over 8 years, and also review 220 cases of APL described in the literature. Based on the review and our experience, we propose that the essential diagnostic criterion for APL is the gradual onset of bilaterally symmetrical loss of subcutaneous fat from the face, neck, upper extremities, thorax, and abdomen, in the "cephalocaudal" sequence, sparing the lower extremities. Analysis of the pooled data revealed that female patients were affected approximately 4 times more often than males. The median age of the onset of lipodystrophy was 7 years. Several autoimmune diseases, in particular systemic lupus erythematosus and dermatomyositis, were associated with APL. The prevalence rates of diabetes mellitus and impaired glucose tolerance were 6.7% and 8.9%, respectively. Approximately 83% of APL patients had low complement (C) 3 levels and the presence of polyclonal immunoglobulin C3 nephritic factor. Twenty-two percent of patients developed membranoproliferative glomerulonephritis (MPGN) after a median of approximately 8 years following the onset of lipodystrophy. Compared with patients without renal disease, those with MPGN had earlier age of onset of lipodystrophy (12.6 +/- 10.3 yr vs 7.7 +/- 4.4 yr, respectively; p < 0.001) and a higher prevalence of C3 hypocomplementemia (78% vs 95%, respectively; p = 0.02). The pathogenesis of fat loss and MPGN in patients with APL remains unclear, but activation of an alternate complement pathway has been implicated. Treating the cosmetic disfigurement by surgical procedures has yielded inconsistent results. The use of thiazolidinediones to treat fat loss in patients with APL remains anecdotal. Prognosis is mainly determined by renal insufficiency due to MPGN.