Enzyme immunoassay of serum beta-2-microglobulin levels in various histological forms of leprosy with special reference to its elevation in type I and type II lepra reactions.

The mean beta-2-microglobulin level in serum (3,362 +/- 2,494 micrograms/liter) for 76 leprosy patients, including 9 borderline-tuberculoid, 8 borderline-borderline, 9 borderline-lepromatous, and 16 lepromatous-lepromatous patients and 34 patients with type I or type II lepra reactions, was significantly higher (P less than 0.001) than that (2,122 +/- 1,844 micrograms/liter) for 35 normal subjects. It decreased significantly (P less than 0.001) as the disease glided down from borderline tuberculoid (3,173 +/- 899 micrograms/liter) to the lepromatous end (1,813 +/- 1,391 micrograms/liter). At the onset of type I or type II reaction, the mean beta-2-microglobulin level in serum increased (4,447 +/- 2,863 micrograms/liter), and it remained unchanged (4,433 +/- 2,623 micrograms/liter) after clinical remission. The beta-2-microglobulin level in serum decreased in 55.5% of the patients tested after subsidence of reaction. The level was significantly higher in patients with type II reactions (5,433 +/- 3,299 micrograms/liter) than in patients with type I reactions (3,558 +/- 2,171 micrograms/liter).