Thrombokinetics in patients with rheumatoid arthritis treated with D-penicillamine

Immune thrombocytopenic purpura associated with rheumatoid arthritis - a report of five cases and review of the literature

Abstract Immune thrombocytopenic purpura (ITP) associated with rheumatoid arthritis (RA) is relatively rare. We describe five cases of RA with ITP. In all five patients, platelet counts were low, platelet-associated IgG levels were elevated, and bone marrow aspiration showed megakaryocytosis. Glucocorticoid therapy was effective in three cases, but the other two cases required immunosuppressants or intravenous γ-globulin in addition to glucocorticoid. We review the reported cases of RA with ITP and discuss the pathophysiology and differential diagnosis of thrombocytopenia in RA.

Rheumatoid arthritis: opposing actions of haemopoietic growth factors and slow-acting anti-rheumatic drugs

The pathogenesis of rheumatoid arthritis and the mode of action of anti-rheumatic drugs are unknown. This hypothesis proposes that haemopoietic growth factors (colony stimulating factors [CSFs]) have an important role in rheumatoid arthritis as regulators of myelopoiesis and as activators of inflammatory leucocytes. It also suggests that slow-acting anti-rheumatic drugs may work by inhibiting myelopoiesis. This opposition to one of the actions of the CSFs would result in fewer inflammatory cells in the inflamed joints.

D-penicillamine

D-Pen represents an effective treatment for a proportion of patients with RA and PSS. Its status in the treatment of juvenile RA is uncertain. The best results will be obtained by a skillful, careful physician maintaining careful surveillance for toxicity. Neither the mode of action nor the mechanisms of toxicity are well understood in RA. Consequently, safer and more effective analogues of D-pen have not been produced.

Platelet aggregation and thromboxane A2 release in primary biliary cirrhosis and effect of D-penicillamine treatment

Platelet function was assessed in 28 patients with primary biliary cirrhosis (PBC), of whom 10 were receiving D-penicillamine. Patients not on D-penicillamine treatment had platelet aggregation similar to that in the healthy control group; the group treated with D-penicillamine showed significantly enhanced platelet aggregation in response to threshold doses of adrenaline and collagen but not ADP. Median thromboxane B2 production was also higher in D-penicillamine treated patients than in controls or untreated patients; this difference did not reach statistical significance. The addition of D-penicillamine in vitro to platelet rich plasma from normal subjects was shown to enhance adrenaline- and collagen-induced platelet aggregation. Abnormalities of platelet function in PBC patients did not correlate with serum cholesterol concentration or with liver function tests but were related to the stage of disease. The present study emphasises the need to consider the aetiology, disease stage and type of treatment when assessing platelet function and prostanoid release in liver disease.