IntroductionThe TAM (tyro 3, axl, mer) kinases are key regulators of innate immunity and are important in the phagocytosis of apoptotic cells. Gas6 and protein S are ligands for these TAM kinases and bind to phosphatidyl serine residues exposed during apoptosis. In animal models, absence of TAM kinases is associated with lupus-like disease. To test whether human systemic lupus erythematosus (SLE) patients might have deficient levels of TAM ligands, we measured Gas 6 and protein S levels in SLE.Methods107 SLE patients were recruited. Of these, 45 SLE patients were matched age, gender and ethnicity with normal controls (NC). Gas6 and free protein S were measured with sandwich enzyme linked immunosorbent assays (ELISAs).ResultsOverall, the plasma concentrations of Gas6 and free protein S were not different between 45 SLE patients and 45 NC. In SLE patients, the levels of free protein S were positively correlated with age (r = 0.2405, P = 0.0126), however those of Gas6 were not. There was no correlation between the concentrations of Gas6 and free protein S in individuals. Levels of free protein S were significantly lower in SLE patients with a history of serositis, neurologic disorder, hematologic disorder and immunologic disorder. Gas6 levels were elevated in patients with a history of neurologic disorder. The SLE patients with anti-Sm or anti-cardiolipin IgG showed lower free protein S levels. Circulating free protein S was positively correlated with complement component 3 (C3) (r = 0.3858, P < 0.0001) and complement component 4 (C4) (r = 0.4275, P < 0.0001). In the patients with active BILAG hematologic involvement, the levels of free protein S were lower and those of Gas6 were higher.ConclusionsIn SLE, free protein S was decreased in patients with certain types of clinical history and disease activity. Levels of free protein S were strongly correlated with C3 and C4 levels. Gas6 levels in SLE patients differed little from levels in NC, but they were elevated in the small numbers of patients with a history of neurological disease. The correlation of decreased protein S levels with lupus disease activity is consistent with a role for the TAM receptors in scavenging apoptotic cells and controlling inflammation. Protein S appears more important functionally in SLE patients than Gas6 in this regard.

An understanding of the cytokine cascade in a rheumatoid joint has led to the development of new therapeutic options, including drugs targeting tumor necrosis factor-alpha (TNF-alpha). The safety profile of these agents in patients with hepatitis-induced liver disease, however, remains a concern because of risks associated with immune suppression. To examine the effect of three different TNF-alpha antagonists, infliximab, etanercept, and adalimumab, on serum transaminases and hepatitis viral load in patients with rheumatoid arthritis (RA) and concurrent hepatitis B (HBV) or hepatitis C (HCV). Medical records of 11 patients with diagnosis of RA and documented seropositivity for hepatitis B or hepatitis C were retrospectively reviewed for worsening of hepatic inflammation and viral proliferation as measured by a rise in aspartate aminotransferase (AST) or alanine aminotransferase (ALT) and viral load while using these agents. Three patients had RA with concurrent chronic HBV and eight patients had RA with concurrent chronic HCV. Seven patients remained on a single anti-TNF-alpha agent and four patients switched to a second anti-TNF-alpha agent due to treatment failure. Two patients showed a transient elevation in AST and/or ALT from normal, but in all 11 patients, AST and ALT levels were within one time the upper range of normal at the conclusion of the study. No significant increase in viral load was seen except one patient who showed a fourfold increase from baseline. Our case series supports results obtained from previous studies examining the safety of anti-TNF-alpha agents in patients with underlying hepatic disease. Use of these agents in patients with HBV or HCV may be associated with a transient transaminitis but appears to be safe overall. In both groups, frequent monitoring of serum transaminase levels and viral load is essential.

Rheumatoid arthritis (RA) and multiple sclerosis (MS) share similar pathophysiologic processes but coexistence of both diseases in the same patient has rarely been described. We describe the case of a 32 year old woman with rheumatoid arthritis treated with 12.5 mg of methotrexate once a week and 1 mg folic acid who developed paresthesias of her upper and lower extremities. Three years later, she acutely developed 6th nerve palsy, gait imbalance and urinary urgency and a diagnosis of multiple sclerosis was made. The use of methotrexate, though effective in controlling her rheumatoid arthritis, did not influence the development or progression of her multiple sclerosis. Although RA and MS may coexist in the same patient, treatment of one disease may have no influence on the clinical course of the other. Thus, the mechanism by which methotrexate suppresses disease activity in RA but not in MS despite both being T-cell mediated autoimmune diseases requires further investigative studies.

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