Genetics of Neonatal Lupus Erythematosus Risk and Specific Manifestations.

OBJECTIVE: Neonatal lupus erythematosus (NLE) is a passively acquired autoimmune disease of infants born to anti-Ro and/or La autoantibody positive mothers. Genetics may impact NLE risk. We analyzed the genetics of infants and anti-Ro antibody positive mothers, with NLE and NLE specific manifestations. METHODS: Infants and mothers from a tertiary care clinic underwent genotyping on the Global Screening Array. We created additive non-HLA and HLA polygenic risk scores (PRSs) for systemic lupus erythematosus (SLE), from one of the largest genome wide association studies. Outcomes were any NLE manifestations, cardiac NLE, and cutaneous NLE. We tested the association between SLE-PRSs in the infant, mother, and the PRS difference between the mother and infant with NLE outcomes, in logistic regression and generalized linear mixed models (Bonferroni P<0.02). We also performed HLA-wide analyses for the outcomes (P<5.00x10-8). RESULTS: The study included 332 infants, 270 anti-Ro antibody positive mothers, and 253 mother-infant pairs. A large proportion of mothers (40.3%) and infants (41.3%) were European, and 50.0% of infants were female. More than half of the infants had NLE (53.0%), including 7.2% with cardiac NLE and 11.7% with cutaneous NLE. We did not identify significant associations between infant, maternal, or maternal-infant PRSs and any NLE outcomes. HLA-wide analyses did not identify NLE risk alleles. CONCLUSION: In a multiethnic cohort of infants and anti-Ro antibody positive mothers, we did not identify a significant association between SLE genetics and risk of NLE outcomes.

Schizophrenia Genetics and Neuropsychiatric Features in Childhood-onset Systemic Lupus Erythematosus.

OBJECTIVE: We examined the association between schizophrenia genetic susceptibility loci and neuropsychiatric systemic lupus erythematosus (NPSLE) features in childhood-onset SLE (cSLE) participants. METHODS: Study participants from the Lupus Clinic at the Hospital for Sick Children, Toronto, met ≥ 4 of the American College of Rheumatology and/or SLE International Collaborating Clinics SLE classification criteria and were genotyped using the Illumina Multi-Ethnic Global Array or the Global Screening Array. Ungenotyped single-nucleotide polymorphisms (SNPs) were imputed, and ancestry was genetically inferred. We calculated 2 additive schizophrenia-weighted polygenic risk scores (PRS) using (1) genome-wide significant SNPs (P < 5 × 10-8), and (2) an expanded list of SNPs with significance at P < 0.05. We defined 2 outcomes compared to absence of NPSLE features: (1) any NPSLE feature, and (2) subtypes of NPSLE features (psychosis and nonpsychosis NPSLE). We completed logistic and multinomial regressions, first adjusted for inferred ancestry only and then added for variables significantly associated with NPSLE in our cohort (P < 0.05). RESULTS: We included 513 participants with cSLE. Median age at diagnosis was 13.8 years (IQR 11.2-15.6), 83% were female, and 31% were of European ancestry. An increasing schizophrenia genome-wide association PRS was not associated with NPSLE (OR 1.04, 95% CI 0.87-1.26, P = 0.62), nor with the NPSLE subtypes, psychosis (OR 0.97, 95% CI 0.73-1.29, P = 0.84) and other nonpsychosis NPSLE (OR 1.08, 95% CI 0.88-1.34, P = 0.45), in ancestry-adjusted models. Results were similar for the model including covariates (ancestry, malar rash, oral/nasal ulcers, arthritis, lymphopenia, Coombs-positive hemolytic anemia, lupus anticoagulant, and anticardiolipin antibodies) and for the expanded PRS estimates. CONCLUSION: We did not observe an association between known risk loci for schizophrenia and NPSLE in a multiethnic cSLE cohort. This work warrants further validation.

Ethnicity and Neonatal Lupus Erythematosus Manifestations Risk in a Large Multiethnic Cohort.

OBJECTIVE: To evaluate the association between ethnicity and neonatal lupus erythematosus (NLE), as well as specific NLE manifestations in a large multiethnic population. METHODS: We conducted a cohort study of the children (≤ 1 yr of age) seen in the NLE clinic at The Hospital for Sick Children (SickKids), between January 2011 and April 2019. The cohort was divided into European, non-European, and mixed European-non-European groups according to parent-reported child's ethnicity (Canada Census categories). Outcomes were NLE and specific NLE manifestations (cardiac, cutaneous, cytopenias, transaminitis, and macrocephaly). The frequency of NLE and specific manifestations were compared between ethnic groups (Fisher exact test). We tested the association between ethnicity and (1) NLE risk, and (2) specific NLE manifestations with logistic regression models, including covariates for child's sex, maternal rheumatic disease status during pregnancy, and maternal use of antimalarials during pregnancy (multiple comparisons threshold P < 0.008). RESULTS: We included 324 children born to 270 anti-Ro antibody-positive mothers. Median age at first visit was 1.8 (IQR 1.4-2.3) months, and median follow-up time was 12 (IQR 2-24) months. The majority was non-European (48%), with 34% European, and 18% mixed European-non-European. There was no significant association between non-European ethnicity (OR 1.18, 95% CI 0.71-1.94, P = 0.51), mixed European-non-European ethnicity (OR 1.13, 95% CI 0.59-2.16, P = 0.70), and NLE risk compared with European ethnicity. We also did not find an association between ethnicity and specific NLE manifestations in univariate or multivariable-adjusted models. CONCLUSION: In a large multiethnic cohort, there was no association between a child's ethnicity and NLE risk or specific NLE manifestations.