INCREASED LEVELS OF INTERLEUKIN-6 (IL-6) IN SERUM AND SPONTANEOUS IN-VITRO PRODUCTION OF IL-6 BY LYMPH-NODE MONONUCLEAR-CELLS OF PATIENTS WITH ANGIOIMMUNOBLASTIC LYMPHADENOPATHY WITH DYSPROTEINEMIA (AILD), ANDCLINICAL EFFECTIVENESS OF CYCLOSPORINE-A

Serum levels of cytokines and in vitro cytokine production by lymph no de mononuclear cells (LNMC) were studied in four patients with angio-i mmunoblastic lymphadenopathy with dysproteinemia (AILD) or AILD-type T cell lymphoma. An increased level of serum interleukin-6 (IL-6) was d etected on initial diagnosis in both of two patients examined. Spontan eous production of IL-6 by LNMC was detected in all four patients stud ied. Immunosuppressive therapy with cyclosporin A (CsA) was attempted in a 68-year-old man, who was refractory to intensive combination chem otherapy. The increased level of IL-6 in this patient decreased to nor mal within 3 weeks of CsA administration and the patient became sympto m-free. One and a half months later, the IL-6 level gradually increase d along with clinical exacerbation. We also measured serum levels of I L-1 alpha, IL-2, IL-4, IFN-alpha, gamma and TNF-alpha in parallel with IL-6, but these factors were only sporadically detected. IL-6 product ion by LNMC was stimulated by IL-2 but inhibited by CsA. These observa tions suggest that IL-6 is one of the important cytokines to be involv ed in the pathophysiology of AILD and CsA is a useful reagent for reli eving symptoms.