Low serum HDL-cholesterol is associated with raised tumor necrosis factor-alpha during ENL reactions.

The concentrations of serum lipids and tumor necrosis factor (TNF) were measured in leprosy patients across the spectrum of the disease and in erythema nodosum leprosum (ENL) patients at the onset of the reaction and after the reaction had clinically subsided. Lepromatous/borderline lepromatous (LL/BL) patients had significantly higher serum triglyceride and lower HDL-cholesterol levels; there was no such change in the tuberculoid/borderline tuberculoid (TT/BT) patients. The household contacts (HC) of the LL/BL patients also had significantly lower serum HDL levels. ENL patients during the acute phase of the reaction had significantly lower total, LDL-, HDL-cholesterol levels compared to the stable LL/BL patients, and these changes were reversible to pre-ENL levels after the reaction had subsided. Serum TNF levels were significantly higher in household contacts and in LL/BL patients but were not statistically different in TT/BT patients. Serum TNF levels were also significantly higher during the acute phase of ENL, and declined after the clinical remission of the reaction to levels comparable with those of LL/BL patients. There was a significant negative correlation between serum TNF and HDL-cholesterol levels during and after ENL reaction. However, there was no such correlation between TNF and total or LDL-cholesterol levels in ENL patients. Our results suggest that the changes in HDL-cholesterol metabolism are a specific part of the host response to lepromatous leprosy and to the ENL reaction and may be mediated by increased TNF production.