In the diagnosis of autoimmune hepatitis type I (AIH-I), the routine assay of indirect immunofluorescence (IFL), used for the detection of anti-smooth muscle antibodies (ASMAs), has a low predictive value. On the other hand, the enzyme-linked immunosorbent assay (ELISA), which detects anti-cytoskeleton antibodies (ACTAs), presents contradictory results concerning their specific antigenic target. In this study, we first looked for the immunological properties (isotypes and antigenic targets) of autoantibodies in AIH-I and two other control liver diseases: primary biliary cirrhosis (PBC) and viral hepatitis (VH), using ELISA based on cytoskeleton proteins: F-actin, G-actin, myosin, tropomyosin, troponin, desmin, vimentin, keratin, and an extract of HEp-2 carcinoma cells. We also compared the diagnostic value of IFL and ELISA. In contrast to previous studies, we found that actin was not specific for AIH-I. No autoantigen and no antibody class or subclass discriminated AIH-I from the control diseases. IFL is more suitable for AIH-I diagnosis, as 97% of AIH-I sera but only 22% of PBC sera were ASMA-positive. Additionally, 96% of ASMA-positive, and all ASMA-negative sera from all three liver diseases were ACTA-positive. ASMA were mainly IgG, while >50% of ACTA also contained IgA and IgM. These data suggest that ACTAs recognize additional epitopes as compared to ASMAs, and they frequently occur in all liver diseases.

SUMMARY The immune states of 52 patients with myelodysplastic syndromes classified according to the FAB criteria were studied. Serum electrophoresis and immunoelectrophoresis, direct Coombs test, and tests for organ and non-organ specific antibodies were performed. Twenty six patients had immunoglobulin abnormalities: six (11.5%) had monoclonal gammopathy; 17 (32.6%) had polyclonal increases in serum immunoglobulin; while in three (5-8%) immunoglobulin concentrations were decreased. The distribution of immunoglobulin abnormalities among the five myelodysplastic syndrome subtypes was fairly uniform. Results of direct Coombs test were negative in all cases. Organ specific antibodies were not detected in any of the patients tested, although two patients were found positive for antinuclear antibodies. The presence of immunoglobulin abnormalities indicates an involvement of the lymphoplasmatic system in myelodysplastic syndromes.

Ninety-seven sera, 58 from patients with SLE and 39 from patients with other autoimmune rheumatic diseases were tested for anti-ds-DNA antibody activity by ELISA, Farr, and Crithidia Lucilliae assays. Fifty-six per cent of the sera were positive by at least one method. Eighty per cent of the SLE population was positive by ELISA, 39% by Farr Assay and 33% by the Crithidia assay. Crithidia assay exhibited the greater specificity (100%) followed by the Farr Assay (97%) and the ELISA (80%). Sera positive by all methods showed a significantly higher mean value of the ELISA rates, than sera positive only by ELISA (p less than 0.001). When the SLE sera were analyzed according to disease activity, it was shown that ELISA and Farr Assay correlated well with the lupus activity index (LAI) (r less than 0.001). The SLE sera with the higher anti-ds-DNA concentration (sera positive by all 3 methods) did not correlate with LAI when tested by the Farr Assay (0.05 less than p less than 01) in contrast to the ELISA values, which correlated very well (p less than 0.01). Our results indicated that the ELISA is the most sensitive method with reasonable specificity as well. In addition, the ELISA anti-DNA values correlate with the clinical activity of lupus, independently of the anti-ds-DNA levels in the sera. The latter should be attributed to the fact that this method detects all the heterogenous population of anti-ds-DNA.

The incidence of monoclonal gammopathy in 61 patients with chronic myeloproliferative disorders (CMPD) was studied. The distribution of patients among the CMPD subgroups was: chronic myelocytic leukemia, 24 patients; myelofibrosis, 11; polycythemia vera, 15; essential thrombocythemia, 7; unclassified MPD, 4 patients. Monoclonal gammopathy was found in 5 patients (8.2%). Two of these patients (1 IgA/k and 1 IgM/k) had myelofibrosis and 3 (2 IgG/k and 1 IgG/lambda) polycythemia vera. The presence of monoclonal gammopathy indicates an involvement of the lymphoplasmatic system in CMPD.