U1-70-kd autoantibody-positive mixed connective tissue disease in children. A longitudinal clinical and serologic analysis.
OBJECTIVE
To obtain longitudinal data on the clinical, serologic, and immunogenetic features of children with mixed connective tissue disease (MCTD).


METHODS
Eleven children with MCTD were followed up for a mean of 9.8 years. Enzyme-linked immunosorbent assay and immunoblotting were used to analyze sera for autoantibodies to small nuclear ribonucleoprotein polypeptides. HLA types were determined in 9 patients, by microcytotoxicity and DNA typing.


RESULTS
All 11 children had anti-U1-70-kd auto-antibodies. Six of 9 were positive for HLA-DR2, 4 of 9 for HLA-DR4, and 9 of 9 for either HLA-DR2 or DR4. Outcomes were favorable with no functional impairment in 8 of the 11 children and were poor in 3.


CONCLUSIONS
The frequency of HLA-DR2/DR4 is increased among children with anti-U1-70-kd autoantibody positive MCTD.
Hoffman
R W
RW
Department of Internal Medicine, University of Missouri-Columbia School of Medicine.
Cassidy
J T
JT
Takeda
Y
Y
Smith-Jones
E I
EI
Wang
G S
GS
Sharp
G C
GC
D001323:Autoantibodies / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006684:HLA-DR Antigens / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008947:Mixed Connective Tissue Disease / Q000097:blood / Q000235:genetics / Q000276:immunology*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology*
D001323:Autoantibodies; D006684:HLA-DR Antigens; D017412:Ribonucleoprotein, U1 Small Nuclear