Clinical characteristics of neonatal lupus erythematosus complicated by congenital heart block: a multi-center retrospective study in East China

Congenital heart block (CHB) is the most high-risk and prognosis-poor phenotype of neonatal lupus erythematosus (NLE). This study aimed to investigate the clinical characteristics of NLE patients complicated by CHB. This was a multi-center retrospective study. Data were retrospectively collected from NLE patients diagnosed between January 1, 2011, and December 31, 2023, at the Affiliated Children's Hospital of Soochow University, the Affiliated Suzhou Hospital of Nanjing Medical University, Yangzhou Maternity and Child Health Care Hospital, and Huai'an Maternity and Child Health Care Hospital. The patients were divided into CHB and non-CHB groups based on the presence or absence of CHB. Clinical data were compared between the two groups, and logistic regression analysis was performed to identify risk factors associated with CHB. The outcomes of patients in the CHB group were determined through follow-ups. Ninety-one NLE patients were included, with 15 cases complicated by CHB. Among the CHB patients, five had third-degree CHB (5.49%), four had second-degree CHB (4.40%), and six had first-degree CHB (6.59%). The CHB group had significantly higher levels of maternal allergic diseases and double-positive anti-SSA and anti-SSB antibodies compared with the non-CHB group, as well as higher serum levels of creatine kinase (CK), lactate dehydrogenase, and hydroxybutyrate dehydrogenase. Multivariate logistic regression analysis indicated that high serum CK levels predicted CHB in NLE patients. The most common organ involvement in the CHB group was hematologic, followed by the skin, structural heart abnormalities, digestive, and central nervous systems. However, no significant differences were observed between the two groups. In the CHB group, other symptoms resolved spontaneously within the first 2 years of life, and pacemaker implantation was performed in four patients with third-degree CHB at around 1 year of age. Elevated serum CK levels may indicate CHB in NLE patients. Hematologic involvement was most common in NLE patients with CHB. Pacemaker implantation was shown to effectively treat patients with third-degree CHB.