Changes in circulating antibody levels to the major phenolic glycolipid during erythema nodosum leprosum in leprosy patients.

: Circulating antibody levels to the phenolic glycolipid from Mycobacterium leprae and soluble M. leprae antigens were monitored before, during and following ENL episodes in 12 patients. It was observed that during ENL reaction, there was a fall in circulating antibody levels to the phenolic glycolipid but not to the soluble antigens from M. leprae. When the patients had recovered from their ENL reactions, the anti-glycolipid antibody levels usually increased again to levels similar to those observed before the ENL reaction.