Isolated congenital complete heart block in offspring of mothers with primary Sjögren's syndrome

Long-term outcome of mothers of children with isolated heart block in Finland

OBJECTIVE

To study the long-term outcome of mothers of children with isolated heart block in a defined population.

METHODS

We reviewed the Finnish hospital registries for patients born between 1950 and 1999 who had been diagnosed as having isolated heart block before the age of 15 years. We identified 101 children with isolated congenital heart block (CHB) and 55 with isolated heart block detected after the newborn period. Eighty-three (91%) of the 91 mothers of children with CHB and 48 (87%) of the 55 mothers of children with heart block detected after the newborn period were studied according to a protocol defining clinical characteristics (mean 9.9 years, range 0-49 years, and mean 22.9 years, range 4-47 years after the index delivery, respectively). Maternal survival was compared with survival in an age-matched population of normal Finnish women.

RESULTS

Before the index delivery, 29 (37%) of the 78 surviving mothers of children with CHB had a self-reported clinical diagnosis of a chronic autoimmune disease, and 55 (71%) had had symptoms, signs, or abnormal laboratory findings suggesting an underlying subclinical disease. Of the 23 mothers who were completely asymptomatic before the index delivery, 10 (13% of the surviving mothers) remained so after a mean followup of 9.6 years (range 0-21 years). In mothers of children with CHB, clinical characteristics different from those of healthy mothers were photosensitivity, fatigue, dry eyes, and dry mouth. Forty-eight (58%) of these 83 mothers developed an autoimmune disease during followup. The most common diagnosis was primary Sjögren's syndrome (22 definite, 11 probable), followed by systemic lupus erythematosus (SLE). The standardized mortality ratio of mothers of children with CHB was 5.1, and 3 of the 5 deaths were associated with SLE. Mothers of children with heart block detected after the newborn period had similar symptoms and signs of autoimmune diseases as the healthy controls, and their standardized mortality ratio was 1.9.

CONCLUSION

Primary Sjögren's syndrome, either definite or subclinical, is the predominant autoimmune disorder in mothers of children with CHB. Mothers of children with isolated heart block detected after the newborn period do not, as a group, have clinical features suggestive of autoimmune diseases.

Long-term outcome of mothers of children with complete congenital heart block

OBJECTIVES

To determine the health of mothers of offspring with complete congenital heart block (CHB) both at the time of delivery of the affected child and in the long-term, and the percentage of mothers and children with CHB who had anti-SSA/Ro and/or SSB/La antibodies.

PATIENTS AND METHODS

Sixty-four mothers of 64 children with CHB (seen between 1964 and 1993) were identified through the Cardiology database of The Hospital for Sick Children, Toronto, Canada. Medical information from these of children with CHB was evaluated. Data were obtained from the mothers by mailed questionnaire, telephone interview, and/or from the attending physicians. The presence of anti-Ro antibodies and anti-La antibodies were evaluated by ELISA assay.

RESULTS

The mean age at the time of delivery of the first child with CHB was 28 +/- 6 years. At the time of delivery 42 (66%) mothers were healthy, 2 (3%) had systemic lupus erythematosus (SLE), 2 (3%) had linear scleroderma, 2 (3%) had rheumatoid arthritis; 3 (5%) had a history of rheumatic fever (but were otherwise well), 1 (2%) had Sjogren's syndrome (SS), and 12 (19%) had an undifferentiated autoimmune syndrome (UAS) (arthralgia, myalgia, photosensitivity, skin vasculitis, Raynaud's phenomenon). The mean time to follow-up from deliver to study was 121 +/- 88 months. The mean maternal age at study was 38 +/- 9 years. Three of 12 mothers who initially had a UAS progressed to SLE (average follow-up time of 80 months, median 96), and 2 developed SS (with average follow-up time 140 months, median 132) and 1 went into remission. The mean follow-up time for the other mothers who did not develop an autoimmune disease was 150 +/- 102 months. Thirty-six of the 42 initially healthy mothers remained well. One mother developed SLE; 1 developed hyperthyroidism; 1 developed anky-losing spondylitis; and 3 developed an UAS. The mean follow-up time of the 36 mothers who remained healthy was similar (123 +/- 97 months) to the 6 initial healthy mothers who developed an autoimmune disease (121 +/- 36 months). Anti-Ro and/or anti-La antibodies were positive in 32 of 53 (60%) mothers tested. Fourteen of the 53 mothers were symptomatic at the time of delivery and 39 were asymptomatic. Anti-Ro and/or anti-La antibodies were positive in 12 of 13 mothers tested at the time of delivery.

CONCLUSIONS

The long-term maternal outcome in our cohort was very good as most of the initially healthy mothers remained well at follow-up. Twenty-five percent of the mothers with a UAS and only 2% of the initially healthy mothers developed SLE. The development of an autoimmune disease in an asymptomatic mother identified by the birth of a child with CHB was less common in our study than in previous studies. However, close follow-up of mothers with UAS is warranted.

Isolated congenital heart block. Long-term outcome of mothers and characterization of the immune response to SS-A/Ro and to SS-B/La

OBJECTIVE

To study the long-term outcome of mothers of children with isolated congenital heart block (CHB) and to characterize the maternal autoantibody response to SS-A/Ro and SS-B/La.

METHODS

A retrospective clinical study of 33 mothers a mean of 11.2 years (SD 9.2 years, range 0-32 years) after the delivery of their first child with CHB. A clinical and immunologic study of 31 of these mothers, compared with 89 healthy mothers, 45 mothers with systemic lupus erythematosus (SLE), and 19 mothers with primary Sjögren's syndrome (SS), all of whom had healthy children. The specificity of the autoantibody responses to SS-A/Ro and SS-B/La was studied by enzyme-linked immunosorbent assays using purified human recombinant antigens and affinity-purified antigens.

RESULTS

By the time of the analysis, 2 (6%) of the 33 mothers of CHB children had died and 6 (18%) had met the criteria for SLE. As a group, mothers of CHB children had clinical and immunologic characteristics more closely related to primary SS than to SLE or any other connective tissue disease. The predominant autoantibody response was to the SS-A/Ro antigens, notably to the 52-kd SS-A/Ro protein (prevalence 97%). Compared with controls with SLE, mothers of CHB children had higher titers of antibodies to recombinant 52-kd and 60-kd SS-A/Ro proteins and to the affinity-purified SS-A/Ro antigen (P < 0.05, P < 0.01, and P < 0.001, respectively). Compared with controls with primary SS, the autoantibody responses were similar.

CONCLUSION

The predominant autoimmune disorder in mothers of children with CHB is subclinical primary SS. Antibodies to SS-A/Ro appear to be a prerequisite for the development of CHB.