Autoimmune diseases and autoantibodies in the first degree relatives of patients with systemic sclerosis

OBJECTIVE

To determine aggregation of autoimmune diseases in the first degree relatives (FDR) of patients with systemic sclerosis (SSc) and to investigate frequencies of antinuclear antibodies (ANA) and other autoantibodies in the FDRs and spouses of patients with SSc.

METHODS

Information on FDRs including history of autoimmune disease was obtained from unrelated SSc probands in the Scleroderma Family Registry and DNA Repository. FDRs were contacted to verify any reported autoimmune diseases. The prevalence of autoimmune disease in probands' families was compared with the corresponding prevalence in controls' families as reported in the literature. Furthermore, sera from probands' FDRs and spouses in addition to unrelated controls were investigated for the presence of autoantibodies (ANA).

RESULTS

We investigated 4612 FDRs of 1071 SSc probands. SSc probands with anti-centromere antibodies (ACA) and limited disease type were more likely to report familial autoimmunity (p=0.022 and p=0.041, respectively). The four most prevalent autoimmune diseases among SSc probands' FDRs were hypothyroidism (4%), Rheumatoid arthritis (1.5%), hyperthyroidism (1.3%) and systemic lupus erythematosus-SLE (0.4%). Compared to control families, SLE, hypothyroidism and hyperthyroidism were more common in SSc probands' families. The most striking increase for familial prevalence was observed in SLE (OR=16.98, 95% CI=1.02-227.82, p=0.004). ANA was present in 14.2% of probands' FDR's and 8.6% of spouses and did not differ from the prevalence of ANA among controls (p=0.124 and p=0.477, respectively). Only two FDRs of probands had ACA while none had anti-topoisomerase antibodies.

CONCLUSION

Our study implies varying degrees of risk for familial autoimmunity among subtypes of SSc and provides further support for common genetic and potentially environmental factors leading to SSc and SLE.

Inhibition of the epidermal growth factor receptor tyrosine kinase activity by leflunomide

The active metabolite of leflunomide, A77 1726 inhibits the proliferation of a variety of mammalian cell lines in culture. Epidermal growth factor (EGF)-dependent proliferation is inhibited by A77 1726 at an effective dose of 30-40 microM. A77 1726 appears to directly inhibit the EGF receptor tyrosine-specific kinase activity both in intact cells and purified EGF receptors at the same effective dose. These data suggest that leflunomide inhibits cellular proliferation by the inhibition of tyrosine-specific kinase activities.

Immunomodulation of proteoglycan-induced progressive polyarthritis by leflunomide

Proteoglycan-induced arthritis is a mouse model displaying many similarities to human rheumatoid arthritis and ankylosing spondylitis which has been documented by clinical and histopathological studies. The development of the disease in genetically susceptible BALB/c mice is dependent upon the expression of both cell-mediated and humoral immunity to host mouse cartilage proteoglycan. Since both development and regression of acute inflammatory processes in joints correlate directly with the serum antibody level to mouse cartilage proteoglycan, it is believed that these autoreactive antibodies may play a key role in the pathological mechanism of proteoglycan-induced arthritis. The treatment of arthritic animals with an immunomodulating agent (leflunomide) suppressed acute inflammatory events, protected animals from new inflammatory episodes or acute exacerbations in chronically inflamed joints and blocked pathological processes in arthritic joints, which otherwise led to progressive deformities, ankylosis and the loss of articular cartilage. We conclude that the suppressive effect of leflunomide (HWA 486) in proteoglycan-induced arthritis primarily is due to the suppression of autoantibody formation and that the drug may be a potential agent in human therapy as well. Further, we feel that this novel model of murine polyarthritis will extend further the pharmacological repertoire necessary to discover innovative antirheumatic drugs.

Clinical correlates of intent in attempted suicide

The seriousness of suicide attempts was evaluated in 62 consecutive referrals in 2 general hospitals. As measured by the Suicide Intent Scale (SIS) the majority of cases had a low to moderate intention to die. Increasing age, psychosis and deliberate self-injury were associated with high suicidal intent. Hopelessness and a sense of isolation are significantly more frequent antecedent ideo-affective states in cases with high intent and anger and frustration are more prevalent in cases with low intent. Two other measures of seriousness, the medical condition on admission and lethality of the method used, correlate significantly with the degree of intent. The SIS can distinguish between relatively homogeneous subgroups of suicide attempters for depth studies of aetiology and management.

Leflunomide (HWA 486), a novel immunomodulating compound for the treatment of autoimmune disorders and reactions leading to transplantation rejection

Leflunomide has been shown to be very effective in preventing and curing several autoimmune animal diseases. Further, this agent is as effective as cyclosporin A in preventing the rejection of skin and kidney transplants in rats. Preliminary results from patients suffering from severe cases of rheumatoid arthritis demonstrated that clinical and immunological parameters could be improved with leflunomide therapy. Mode of action studies revealed that this substance antagonizes the proliferation inducing activity of several cytokines and is cytostatic for certain cell types. In this light, we could show that tyrosine phosphorylation of the RR-SRC peptide substrate and the autophosphorylation of the epidermal growth factor (EGF) receptor were, dose dependently, inhibited by leflunomide. EGF activates the intrinsic tyrosine kinase of its receptor, which stimulates the phosphorylation of a variety of peptides, the amino acid residue in all cases is tyrosine. These results indicate that much of leflunomide's activity could be due to the inhibition of tyrosine-kinase(s), which is an important general mechanism for the proliferation of various cell types. Thus, leflunomide, which is effective against autoimmune diseases and reactions leading to graft rejection, would seem to have a mode of action separating it from known immunosuppressive drugs.