ABSTRACT
OBJECTIVE: To determine the utility of anti-extractable nuclear antigen (anti-ENA) antibodies detected by enzyme-linked immunosorbent assay as a predictor for the diagnosis of systemic lupus erythematosus (SLE). METHODS: Among 2,185 serum samples sent for testing for antinuclear antibodies (ANA) by indirect immunofluorescence, 259 consecutive patients with positive ANA were identified. Medical charts of these patients were reviewed to assess the clinical diagnosis, with the reviewer having no knowledge of the anti-ENA result. Clinical data were abstracted for all patients, and diagnoses established using American College of Rheumatology criteria. The utility of ENA antibodies in the diagnosis of SLE was determined by univariate and multivariate analysis among all patients who were positive for ANA, patients who were positive for ANA and for anti-double-stranded DNA (anti-dsDNA), and patients who were positive for ANA and negative for anti-dsDNA. Clinical differences between SLE patients with and those without anti-ENA antibodies were assessed. RESULTS: Anti-ENA antibodies, especially anti-Ro/SS-A, showed strong predictive diagnostic value among ANA+/anti-dsDNA- patients, but were of no utility among ANA+/anti-dsDNA+ patients. The only clinical manifestations that were more common among anti-ENA+ SLE patients were pleuritis and the use of hydroxychloroquine. CONCLUSION: The presence of anti-ENA antibodies, especially anti-Ro/SS-A, is a useful predictor for the diagnosis of SLE, primarily among patients attending a referral rheumatology center who are positive for ANA and negative for anti-dsDNA. No major clinical differences were noted among ANA+ SLE patients with versus those without ENA.
Subject(s)
Antibodies, Antinuclear/blood , Autoantigens/analysis , Lupus Erythematosus, Systemic/diagnosis , RNA, Small Cytoplasmic , Ribonucleoproteins, Small Nuclear , Ribonucleoproteins/analysis , Biomarkers/analysis , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/immunology , Male , Sensitivity and Specificity , snRNP Core Proteins , SS-B AntigenABSTRACT
The relationship between hemophiliac immunodeficiency and exposures to factor VIII concentrate, LAV/HTLV-III retrovirus, and infection with Epstein-Barr virus and cytomegalovirus was examined. Exposure to factor VIII concentrate was significantly correlated with decreased percentages of T helper/inducer cells, decreased T helper/suppressor cell ratios, and decreased proliferative responses to plant mitogens. LAV/HTLV-III seropositivity was the primary predictor of increased percentages of HLA-DR-bearing mononuclear cells and decreased proliferative responses to pokeweed mitogen. Epstein-Barr virus and cytomegalovirus infections acted in a synergistic manner with LAV/HTLV-III to produce immunoregulatory defects. Increased percentages of T suppressor cells and decreased delayed cutaneous hypersensitivity skin test responses were observed in LAV/HTLV-III seropositive hemophiliacs infected with Epstein-Barr or cytomegalovirus. We conclude that hemophiliacs receiving commercial factor VIII concentrate experience several stepwise incremental insults to the immune system: alloantigens in factor VIII concentrate, LAV/HTLV-III infections, and herpesvirus infections.