FRI0533 ETHNICITY AND NEONATAL LUPUSRISK IN A LARGE MULTI-ETHNIC COHORT

Abstract

Background Neonatal Lupus (NL) is an acquired autoimmune disorder of newborns secondary to the transplacental passage of maternal anti-Ro and/or anti-La. Approximately 2% of children exposed to these antibodies develop NL. Prior studies have suggested that babies of non-European ancestry have a higher proportion of cardiac NL when compared to babies of European ancestry. This finding has not been consistently replicated. Objectives To examine the association between ethnicity and clinical manifestations of NL in our multi-ethnic population. Methods We conducted a cohort study of our large, multi-ethnic NL clinic population. The Neonatal Lupus clinic at the Hospital for Sick Children, Toronto, Canada was established in 1986. Children born to anti-Ro and/or anti-La antibody positive mothers are referred to the NL clinic. Antenatal testing is completed due to maternal rheumatologic diagnosis, a prior child born with NL and/or a history of symptoms that prompted physician testing for these antibodies. Beginning in 2011, families routinely reported ethnicity (Canadian census categories). We divided our NL patient cohort in European and non-European groups; the non-European group includes patients of African, Latin American, East Asian, South Asian and Mixed non-European ancestry (i.e. combination of two or more of non-European ethnicities). We included children assessed in the NL clinic ≤ 1 year of age between January 2011 to April 2018. There were 59 children censored for this analysis (7 missing ethnicity and 52 Mixed European-Non European ancestry). We analyzed prospectively collected data from our NL database, on specific NL manifestations: cardiac (heart block, myocarditis, endocardial fibroelastosis), dermatologic (typical rash of NL), hematologic (cytopenias), hepatic (transaminitis) and neurologic (macrocephaly). The frequency of NL clinical manifestations was compared among ethnicity groups (Fisher’s exact test). We tested the association between ethnicity and NL clinical manifestations in logistic models. Results Our study included 301 children, 149 (50%) female and 164 (55%) with NL (Table 1). The median follow-up period was 12.2 months (IQR: 4.8, 28.8 months). Ethnicity data was available for 294 (98%) of the children. The non-European group (40%) was comprised of East Asian (14%), South Asian (13%), African (10%), Latin American (2%) and Mixed Non-European ancestry (17%). We did not observe a difference between European and Non-European babies in the proportion with NL, nor any difference in the frequency of specific NL manifestations (p-values > 0.3). Conclusion In our multiethnic NL cohort of children born to mothers with positive anti-Ro and/or anti-La antibodies, there was no association between ethnicity and NL, nor specific NL manifestations. Future analyses will examine the effect of maternal ethnicity and rheumatic disease status on the risk of NL and specific NL manifestations.