Impact of the 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus in a Multicenter Cohort Study of 133 Women With Undifferentiated Connective Tissue Disease.

OBJECTIVE: We aimed to investigate the impact of applying the 2019 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for systemic lupus erythematosus (SLE) in a previously described cohort of women with undifferentiated connective tissue disease (UCTD). METHODS: This study included 133 women with UCTD. At the time of inclusion into the study, none of the patients met any classification criteria for other defined systemic connective tissue disease. RESULTS: When applying the 2019 EULAR/ACR classification criteria to the cohort, 22 patients (17%) fulfilled the classification criteria for SLE. Patients classified as having SLE had significantly higher frequencies of mucocutaneous manifestations (23% versus 5%; P = 0.007), arthritis (59% versus 17%; P < 0.001), isolated urine abnormalities (18% versus 1%; P < 0.001), and highly specific antibodies (50% versus 15%; P < 0.001) compared to the other patients with UCTD. At follow-up, these patients were statistically significantly more likely to also meet the 1997 ACR revised SLE criteria and the Systemic Lupus International Collaborating Clinics (SLICC) criteria (18.2% versus 1.8%; P < 0.001) compared to the other UCTD patients. Patients who were diagnosed as having SLE according to the ACR 1997 update of the SLE revised criteria and the SLICC criteria during the follow-up scored higher on outcome measures when classified as having SLE according to the new 2019 EULAR/ACR classification criteria when compared to the other patients with UCTD (mean ± SD score 8.3 ± 3.7 versus 4.5 ± 4; P < 0.05). CONCLUSION: When applying the 2019 EULAR/ACR criteria for SLE in a cohort of patients with UCTD, we observed that in up to 17% of cases the original classification could be challenged. New implementation will help to identify earlier patients at higher risk of developing more severe CTD manifestations.

A multicentre study of 244 pregnancies in undifferentiated connective tissue disease: maternal/fetal outcomes and disease evolution.

OBJECTIVES: To investigate fetal/perinatal and maternal outcomes from a large multicentre cohort of women diagnosed with UCTD. METHODS: This multicentre retrospective cohort study describes the outcomes of 224 pregnancies in 133 consecutive women with a diagnosis of UCTD, positive for ANA and aged <45 years old at study inclusion. RESULTS: Of the 224 pregnancies analysed, 177 (79%) resulted in live births, 45 (20.1%) in miscarriages (defined as pregnancy loss before 12 weeks' gestation), 2 (0.9%) in stillbirths (pregnancy loss after 20 weeks' gestation) and 6 (2.7%) cases showed intrauterine growth restriction. Miscarriages and stillbirths were strongly associated with the presence of aPL and ENA antibodies (P < 0.05). Maternal pregnancy complications were as follows: 5 (2.2%) cases developed pre-eclampsia, 11 (4.9%) cases gestational hypertension and 12 (5.4%) cases gestational diabetes. Joint involvement represented the most frequent clinical manifestation of the cohort (57.9%), followed by RP (40.6%), photosensitivity (32.3%) and haematological manifestations (27.1%). The rate of disease evolution of our cohort from a diagnosis of UCTD to a diagnosis of definite CTD was 12% within a mean time of 5.3 ± 2.8 years. With a total follow-up after first pregnancy of 1417 patient-years, we observed the evolution to a defined CTD in one out of every 88 patient- years. CONCLUSION: In our multicentre cohort, women with UCTD had a live birth rate of 79%. Women with UCTD should be referred to specialist follow-up when planning a pregnancy. ENA profiling and aPL testing should be mandatory in this setting, and further therapeutic approaches and management should be planned accordingly.