Depressive effect of plasma on lymphocyte transformation in nodular lepromatous leprosy.

Lymphocytes from 20 patients with NLL were cultured stimulated with PHA in presence of autologous and homologous plasma; the same procedure was carried out with lymphocytes from 20 healthy people, utilized as controls. A diminished capacity of transformation was noticed when lymphocytes, both from patients and controls, were cultured in plasma from NLL patients, this suggesting the presence of a plasmatic inhibitor factor. This effect was particularly noticeable in 8 cases (40%) of the studied patients. Regarding the nature of the plasmatic factor, the concentration of C reactive protein, rheumatoid factor, alpha, beta and gamma globulins, did not show any correlation with the presence of the depressive activity. It seems that at least in some cases, the impaired lymphocyte transformation observed in NLL patients, can be due to an immune complex present as a plasma factor, rather to an intrinsic defect in lymphocytes.