The Importance of an Early Diagnosis in Systemic Lupus Erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease with a high degree of variability at onset, making it difficult to reach a correct and prompt diagnosis. OBJECTIVES: To present the difficulties faced by the clinician in making a SLE diagnosis, based on the characteristics at study entry of an Italian cohort of SLE patients with recent onset as compared to two similar cohorts. METHODS: Beginning on 1 January 2012 all patients with a diagnosis of SLE (1997 ACR criteria) and disease duration of less than 12 months were consecutively enrolled in a multicenter prospective study. Information on clinical and serological characteristics was collected at study entry and every 6 months thereafter. RESULTS: Our cohort consisted of 122 patients, of whom 103 were females. Among the manifestations included in the 1997 American College of Rheumatology (ACR) criteria, cutaneous, articular and hematologic symptoms were the most prevalent symptoms at study entry. CONCLUSIONS: Data from the literature confirm that the diagnosis of SLE is challenging, and that SLE is a severe disease even at onset when a prompt diagnosis is necessary for initiating the appropriate therapy.

Detection of anti-IFI16 antibodies by ELISA: clinical and serological associations in systemic sclerosis.

OBJECTIVES: To validate the clinical significance of anti-IFI16 autoantibodies in SSc and assess their associations with serological markers of SSc. METHODS: A semi-quantitative ELISA was used to detect anti-IFI16 autoantibodies in the sera of 344 SSc patients from seven Italian hospitals and 144 healthy controls. SSc-associated autoantibodies [anti-RNA polymerase III (anti-RNAP III) antibodies, anti-centromere, anti-topo I] and IF patterns were evaluated using commercial assays. Statistical analyses were performed to test clinical and serological associations. RESULTS: The results of this study confirm a significant prevalence (29%) of anti-IFI16 antibodies in the SSc population (n = 344). Anti-IFI16 antibodies were also detected in 30% of the SSc patients who tested negative for both ACAs and anti-topo I (anti-Scl70) antibodies. In this subgroup of patients, anti-IFI16 antibodies were significantly associated with the limited cutaneous form of SSc with a sensitivity of 40% and a specificity of 81%. Moreover, analysis of the distribution of anti-RNAP III antibodies vs anti-IFI16 in the same SSc population showed that they were mutually exclusive. IIF revealed no association between anti-IFI16 and fluoroscopic patterns, due to a lack of IFI16 autoantigen in HEp-2 cells. Anti-IFI16 antibody levels were also significantly associated with heart involvement. CONCLUSIONS: Anti-IFI16 autoantibodies are frequently detected in SSc, displaying clinical and laboratory associations, and being particularly useful for diagnosis and disease classification in patients who are negative for other SSc serological markers.