Concealed hypothyroidism in patients with myeloperoxidase antineutrophili cytoplasmic autoantibodies- (MPO-ANCA) positive renal disease.
OBJECTIVE
To elucidate the relationship between thyroid disorders and myeloperoxidase (MPO) antineutrophili cytoplasmic autoantibodies-(ANCA) positive renal disease, we investigated the prevalence of thyroid diseases in patients with them.


METHODS
The subjects consisted of 10 patients (6 males and 4 females) diagnosed as having MPO-ANCA-positive renal disease in our hospital. To evaluate thyroid function, serum thyroid-stimulating hormone (TSH) and free-thyroxine (FT4) levels were measured by a immunoradiometric assay (IRMA) and a radioimmunoassay (RIA), respectively. Thyroid autoantibodies against microsomal antigen and thyroglobulin were measured by means of particle agglutination. In addition, antibodies against thyroid peroxidase (TPO-Ab) and purified thyroglobulin (Tg-Ab) were also determined by RIA. To assess the disease activity, we employed Birmingham Vasculitis Activity Score (BVAS).


RESULTS
The results were that 4 out of 10 patients (40%) were accompanied by hypothyroidism, including 2 patients with subclinical hypothyroidism and I during thyroid hormone replacement therapy. The BVAS of the hypothyroidism group (group A) was significantly lower (p < 0.05) than that of non-hypothyroidism group (group B), 18.5 +/- 9.0 (mean +/- SD) versus 24.2 +/- 16.6. MPO-ANCA titers were not significant between the two groups, 376.8 +/- 316.8 EU versus 311.5 +/- 203.6 EU.


CONCLUSIONS
Thyroid disorder, especially hypothyroidism would not be a rare complication in patients with MPO-ANCA-positive renal disease. We should concentrate more on thyroid lesion in them.
Tanaka
A
A
Department of Nephrology, Saiseikai Nakatsu Hospital, Osaka, Japan.
Maeda
K
K
Sawai
K
K
Okuda
J
J
Sugawara
A
A
Kuwahara
T
T
D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis; D001327:Autoimmune Diseases / Q000150:complications*; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000209:etiology* / Q000276:immunology; D007453:Iodide Peroxidase / Q000276:immunology; D007674:Kidney Diseases / Q000276:immunology*; D008171:Lung Diseases / Q000150:complications; D008297:Male; D008861:Microsomes / Q000276:immunology; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology*; D015995:Prevalence; D013954:Thyroglobulin / Q000276:immunology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014657:Vasculitis / Q000276:immunology
D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies; D013972:Thyrotropin; D013954:Thyroglobulin; D009195:Peroxidase; D007453:Iodide Peroxidase; D013974:Thyroxine