Frequency of autoantibodies in normal children
A. Martini, R. Lorini, D. Zanaboni, A. Ravelli and R. G. Burgio
Department of Pediatrics, University of Pavia, Italy.
Very few data have been reported on the frequency of autoantibodies (AAs)
in normal children. In the present study we investigated the frequency of
14 AAs in a total of 268 apparently normal children (151 boys and 117
girls; age range, 1 month to 14 years). Forty-one children (22 boys and 19
girls) were positive for at least one AA, usually in a low titer; two
children were positive for two AAs. None of these children had a personal
or family history of autoimmune diseases. The percentage of children
positive for each AA was as follows: antinuclear, 3%; anti-smooth muscle,
2.6%; antireticulin, 2.6%; antimitochondrial, 1.1%; rheumatoid factor,
0.6%; antiribosomal, 0.4%; anti-gastric parietal cells, 5.2%; and
anti-thyroid microsomal, 1.3%. Anti-double-stranded DNA, anti-intestinal
epithelial cells, antiliver and antikidney microsomal, antithyroglobulin,
anti-islet cells, and complement-fixing anti-islet cell antibodies were not
detected in any serum. Fifteen of the 41 positive children were checked for
the presence of AAs two years later; six (40%) were still positive, always
for the same AA, without major differences in titer. Our results suggest
that the overall frequency of AAs in apparently healthy children is quite
similar to that reported in young adults; this AA positivity seems most
often to represent a transient phenomenon.
