Objective: To evaluate autoimmune disease progression in asymptomatic and pauci-symptomatic mothers of children with neonatal lupus (NL).
Methods: Clinical information on mothers enrolled in the Research Registry for NL (RRNL) was obtained from medical records. Genotyping was performed for -308A/G tumour necrosis factor (TNF)alpha, 869T/C transforming growth factor (TGF)beta and -889C/T interleukin (IL)1alpha.
Results: Of the 321 mothers enrolled, 229 had at least 6 months of follow-up. Of the 51 mothers who were asymptomatic at the NL child's birth, 26 progressed: 12 developed pauci-undifferentiated autoimmune syndrome (pauci-UAS), 2 poly-UAS, 7 SS, 4 SLE and 1 SLE/SS. The median time to develop any symptom was 3.15 years. Of the 37 mothers classified as pauci-UAS at the NL child's birth, 16 progressed: 5 developed poly-UAS, 6 Sjögren syndrome (SS), 4 systemic lupus erythematosus (SLE) and 1 SLE/SS. Of the pauci-UAS mothers enrolled within 1 year, the median time to progression was 6.7 years. Four mothers developed lupus nephritis (two asymptomatic, two pauci-UAS). The probability of an asymptomatic mother developing SLE by 10 years was 18.6%, and developing probable/definite SS was 27.9%. NL manifestations did not predict disease progression in an asymptomatic mother. Mothers with anti-Sjögren syndrome A antigen (SSA/)Ro and anti-Sjögren syndrome B antigen (SSB)/La were nearly twice as likely to develop an autoimmune disease as mothers with anti-SSA/Ro only. Only TGFbetaT/T was significantly higher in SLE mothers compared to asymptomatic mothers (p = 0.03).
Conclusions: Continued follow-up of asymptomatic NL mothers is warranted since nearly half progress, albeit few develop SLE. While the anti-SSB/La antibodies may be a risk factor for progression, further work is needed to determine reliable biomarkers in otherwise healthy women with anti-SSA/Ro antibodies identified solely because of an NL child.