Associations Between Classification Criteria Items in Systemic Lupus Erythematosus.

OBJECTIVE: A project aimed at developing new classification criteria for systemic lupus erythematosus (SLE) is based on weighted criteria that include both laboratory and clinical items. Combinations of certain symptoms may occur commonly in SLE, which provides an argument against independently counting these items. The current study was undertaken to evaluate the interrelationship between candidate criteria items in the International Early SLE cohort and in the Euro-Lupus cohort. METHODS: The International Early SLE cohort included 389 patients, who were diagnosed within 3 years prior to the study. Data on the ACR's 1997 update of the SLE revised criteria, the Systemic Lupus International Collaborating Clinics 2012 criteria, and on 30 additional items were collected. To evaluate the interrelationship of the criteria, a tetrachoric correlation was used to assess the degree of association between different manifestations in the same organ system. The correlations identified in the International Early SLE cohort were validated in the Euro-Lupus cohort. RESULTS: A few relevant correlations were observed among specific clinical cutaneous manifestations (in particular, malar rash correlated with photosensitivity, alopecia, and oral ulcers) and serologic manifestations (anti-Sm and anti-double-stranded DNA and anti-RNA polymerase, anti-Ro and anti-La, and antiphospholipid antibodies), and these results were validated in the Euro-Lupus cohort. The associations within the mucocutaneous domain, hematologic and the specific autoantibodies suggest that within a single domain only the highest ranking item should be counted to avoid overrepresentation. CONCLUSION: Some of the candidate SLE criteria cluster within domains. Given these interrelationships, multiple criteria within a domain should not be independently counted. These results are important to consider for the structure of new SLE classification criteria.

Outcomes of lupus and rheumatoid arthritis patients with primary dengue infection: A seven-year report from Brazil.

OBJECTIVE: We described the clinical profile and outcomes of patients with SLE and RA diseases reported to the Brazilian Health Information System with primary dengue infection. METHODS: Databases from the Brazilian Public Health Informatics System (SUS) were linked as the source of information. Three databases comprising different longitudinal information of lupus or rheumatoid arthritis (RA) patients under treatment and care through the Brazilian Health System were linked. Patients who had lupus ICD-9 code or RA ICD-9 code and their treatment approved by SUS were included in the study. In Study 1, we described the clinical characteristics of RA/lupus patients who had dengue infection. In Study 2, we compared RA/lupus patients with or without dengue for hospitalization rates after index dengue diagnosis for dengue-exposed or matching date for dengue-unexposed. RESULTS: We included 69 SLE and 301 RA patients with dengue. In the RA/lupus with dengue case series, hospitalization was found in 24.6% of lupus subjects and of 11.2% of RA subjects. It differed by geographic region (p = 0.03), gender (p = 0.05) and the use of azathioprine (p = 0.02). Dengue was the most frequent reason for hospitalization reported (43.0%). Hospitalization due to dengue was noted in 12 (42.9%) dengue-exposed patients (p = 0.02), while rheumatoid arthritis was reported as the cause of hospitalization in 22.2% of dengue-unexposed (p = 0.005). Five deaths were reported among the dengue-exposed and none among dengue-unexposed. Bacterial infection was the most frequent cause of death. We found that the dengue exposure was associated with an increased risk of hospitalization outcome in RA and lupus patients (RR = 6.2; 95% CI: 2.99-12.94). SUMMARY: We found that when comparing RA/lupus patients with or without dengue, dengue-exposed patients had an increased rates of hospitalization and death.