7. Ishikawa K, Ohira T, Sakata H: Effects of intra-articular injection of halopredone diacetate on the articular cartilage of rabbit knees: a comparison with rnethylprednisolone acetate. Toxicol Appl Pharmacol (in press) 8. Dieppe P, Calvert P: Crystals and J o h t Disease. London, Chapman and Hall, 1983, pp 23-56 9. Ryan LM, Cheung HS, McCarty DJ: Release of pyrophosphate by normal mammalian articular hyaline and fibrocartilage in organ culture. Arthritis Rheum 24: [1522][1523][1524][1525][1526][1527] 1981 Synovial fluid lymphocyte subpopulations in the polyarthritis of immunoblastic lymphadenopathyTo the Editor: Seronegative, inflammatory polyarthritis is an unusual feature of immunoblastic lymphadenopathy (IL) (1-3). Synovianalyses in 2 patients (I ,2) showed inflammatory effusions with a polymorphonuclear cell predominance. In a patient with IL and associated polysynovitis, described here, synovial fluid (SF) revealed a marked mononuclear pleocytosis. Lymphocyte subpopulations in the SF were identified by monoclonal antibody testing.A 45-year-old black man presented in 1981 with a systemic illness ultimately characterized by fever, weight loss, generalized lymphadenopathy, and a polyclonal gammopathy. Findings of peripheral lymph node biopsies were consistent with IL, showing effacement of the normal nodal architecture and a polymorphic infiltration of immunoblasts, plasma cells, and histiocytes. With corticosteroids an initial remission was seen, but adenopathy recurred, waxing and waning with steroid therapy.In June 1983, at the time of a disease exacerbation, the patient exhibited fever, enlarging adenopathy , and an acute, symmetric, inflammatory polyarthritis involving the metacarpophalangeal, proximal interphalangeal, wrist, elbow, knee, and ankle joints. The following studies gave normal or negative results: complete blood count, urinalysis, serum rheumatoid factor (latex fixation), hepatitis B surface antigen, anti-HA antigen, serum glutamic oxaloacetic transaminase, Monospot test, circulating immune complexes (Raji cell assay), blood cultures, antinuclear antibody, C3, C4, and cryoglobulins. Knee roentgenograms showed no erosions or chondrocalcinosis. Arthrocentesis of the left knee yielded 20 ml of yellow, turbid, poorly viscous fluid with a poor mucin clot, total protein of 5.1 gm/dl, white blood cell count of 20,250 (93% mononuclear, 7% polymorphonuclear), and negative findings on crystal search; bacte- rial, mycobacterial, and fungal stains and cultures were negative. Lymphocytes were separated from heparinized aliquots of blood and SF by density gradient centrifugation. Lymphocyte subpopulations were identified by indirect immunofluoresence after reaction with monoclonal antibodies, and results are shown in Table 1.Polyarthritis and fever improved with oral indomethacin; corticosteroids were reinstituted shortly thereafter, due to the development of sterile pulmonary lymphoid infiltrates. The patient's disease progressed to a null cell lymphoma, and he died in late 1983.In contrast to ea...