Isolated autoimmune response: definition, analysis of the prevalence in an outpatient rheumatology clinic, relationship to pre-clinical autoimmune disease and infections by hepatotropic viruses.

OBJECTIVE: To define the clinical significance of non-organ specific autoantibody positivity in patients in whom routine clinical and laboratory examinations did not detect any disease that might have caused the serological finding. METHODS: Out of 1,120 patients consecutively admitted to an outpatient rheumatology clinic, 28 were referred for the evaluation of an autoantibody positivity unrelated to the clinical status. These patients and 28 sex- and age-matched controls underwent a specific work-up with the aim of detecting any underlying infection or autoimmune disease. RESULTS: Eight of the 28 patients (28.5%) were found to be affected by a previously undetected disease: 3 chronic hepatitis C, 3 Sjögren's syndrome, and 2 autoimmune thyroiditis. The remaining 20 did not show any autoimmune or hepatic disease, although 4 of them showed active infection by HBV (n = 1) or HGV (n = 3) and 15 had had a previous infection by hepatotropic viruses (HBV, CMV or EBV). After a follow-up lasting 6-54 months, none of the last 20 patients developed any autoimmune or chronic hepatic disease. CONCLUSIONS: A diagnostic work-up is necessary in patients presenting with unexpected autoantibody positivity in order to detect an underlying pre-clinical autoimmune disease and/or unexpected hepatic infection. Patients in whom such a work-up fails to point out any condition should be further followed in order to make an early diagnosis of autoimmune disease.

Serological and clinical markers of autoimmune disease in HCV-infected subjects with different disease conditions.

OBJECTIVE: To investigate whether the serological markers of autoimmunity and the clinical features of autoimmune disease which occur in hepatitis C virus (HCV)-infected subjects are correlated to each other and/or to the clinical pattern of the disease. METHODS: Seventeen symptom-free, anti-HCV antibody positive subjects, 17 patients with chronic hepatitis C, 21 patients with mixed cryoglobulinemia (MC), and as controls 17 anti-HCV negative patients with dyspepsia were enrolled in a prospective study. A patient history, clinical examination, self-administered questionnaire and laboratory investigations (hepatic enzyme levels, serum HCV-RNA and anti-HCV antibody testing, and serum autoantibody profile) were performed to detect liver and/or autoimmune disease. RESULTS: Serological markers of autoimmunity and clinical findings of autoimmune disease were found to be more frequent in the HCV-infected patients considered as a whole than in controls. However, rheumatoid factor and clinical findings of autoimmune disease were more frequent in MC patients, while anti-smooth muscle antibodies not linked to symptoms or signs of autoimmune disease were detected in all groups of HCV-infected individuals, including healthy carriers and subjects who had recovered from a previous HCV infection. CONCLUSION: Anti-smooth muscle antibodies, a serological marker of autoimmunity, are detectable in HCV-infected subjects whatever their clinical status. Clinical findings of autoimmune disease prevalently occur in patients with mixed cryoglobulinemia.

Antinuclear antibodies in first-degree relatives of patients with polymyositis-dermatomyositis: analysis of the relationship with HLA haplotypes.

Antinuclear antibodies (ANA), as detected by indirect immunofluorescence on HEp-2 cells, have been investigated in five spouses and 41 first-degree relatives of nine probands with polymyositis-dermatomyositis (PM-DM) and in 41 sex- and age-matched controls. ANA were detected in 12 out of the 41 first-degree relatives and in two controls (chi 2 = 6.97; P less than 0.01). HLA typing was done in four out of the nine families; in two of them only, ANA segregated with a haplotype. ANA positivity was not correlated either to sex or to age or to household contact. Our results show that ANA occur in a significant percentage of first-degree relatives of patients with PM-DM. The finding seems to be genetically conditioned.