Active but not quiescent lupus nephritis during pregnancy is associated with a higher rate of adverse obstetric outcomes: Analysis of a prospective cohort.

OBJECTIVE: To compare the maternal-fetal/neonatal outcome in patients with systemic lupus erythematosus (SLE) with and without lupus nephritis (LN) in remission or with active disease. METHODS: A prospective cohort of pregnant patients with SLE (ACR 1997 criteria) was studied from January 2009 to December 2021. Demographic, clinical, biochemical, and immunological variables as well as the usual maternal-fetal/neonatal complications were recorded. We compared four groups according to the status of SLE during pregnancy: patients with quiescent SLE without lupus nephritis, patients with active SLE without lupus nephritis, patients with quiescent lupus nephritis, and patients with active lupus nephritis. Statistical analysis included descriptive statistics, bivariate analysis, and Cox regression analysis. RESULTS: A total of 439 pregnancies were studied, with a median age of 28 ± 6, SLE duration of 60 months (interquartile range 36-120). A higher frequency of maternal and fetal/neonatal complications was observed in patients with active SLE with or without lupus nephritis. Multivariate analysis showed that active LN was a risk factor for gestational hypertension (hazard ratios [HR] 1.95; 95% confidence intervals [CI]: 1.01-6.39), premature rupture of membranes (HR 3.56; 95% CI: 1.79-16.05) and more frequent cesarean section (HR 1.82; 95% CI: 1.13-2.94). CONCLUSION: LN is associated with a higher frequency of maternal complications, especially in those patients with active disease during pregnancy, and those maternal complications had an impact on poor fetal/neonatal outcomes. Strict control and timely care of LN could improve the obstetric prognosis.

Role of rheumatoid factor isotypes and anti-citrullinated peptide antibodies in the differential diagnosis of non-selected patients with inflammatory arthralgia.

BACKGROUND/OBJECTIVES: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by swelling, tenderness and destruction of synovial joints, leading to severe disability and premature mortality. The aim of the study was to determine the diagnostic accuracy of the 3 isotypes of rheumatoid factor (RF), anti-citrullinated peptide antibodies (ACPA) and the combination of both, for the diagnosis of rheumatoid arthritis (RA) in non-selected patients with inflammatory arthralgia. METHODS: We include 129 patients with inflammatory Arthalgia from a third level reference Center of rheumatic diseases in Monterrey, México. Their samples were analyzed for RF isotypes (IgA, IgG, and IgM) by ELISA (EUROINMUN), using a cut-off of 20IU/ml, and for ACPA's 5IU/ml; a medical examination was performed to obtain the definitive diagnoses of the patients. Data analysis was carried out using ROC curves for the measurement of sensitivity, specificity, for diagnostic accuracy to verify if the use of 3 RF isotypes and ACPA had a better prediction for the diagnosis of RA than use only one isotype and the ACPA alone. RESULTS: The ROC showed a sensitivity and specificity of the different antibodies with different cut-off points, being the best for the IgM with 0.802 followed by ACPA, IgA and IgG with 0.771, 0.63, and 0.728 respectively without statistical difference, the sensitivity and specificity of the combination of the 4 antibodies were 81.4 and 73.66%. CONCLUSION: In non-selected patients with inflammatory arthralgia, the combination of ACPA and isotypes of RF did not demonstrate more sensibility and specificity than IgM isoform of rheumatoid factor measurement only. We recommend that in the clinical scenario of arthralgia, where the diagnoses are Lupus, Sjogren syndrome and Osteoarthritis, RF IgM isoform is used followed by ACPA.