Juvenile onset Systemic Lupus Erythematosus thyroid dysfunction: a subgroup with mild disease?
The aim of this study was to evaluate the frequency of thyroid dysfunction and thyroid antibodies in patients with juvenile onset Systemic Lupus Erythematosus (JOSLE) and its association with clinical and immunological features. Seventy-seven patients with JOSLE, 64 females, median age 19 years, were consecutively enrolled from March to December 2007. Clinical data related to thyroid dysfunction and lupus were obtained by chart review and patient interview. Serum levels of TSH, free T4, anti-thyroglobulin (TgAb), anti-thyroperoxidase (TPOAb), TRAb and lupus related autoantibodies were analyzed by standard techniques. Nine patients were diagnosed as hypothyroidism and 4 hyperthyroidism. 28% JOSLE patients had moderate/high titer of thyroid antibodies: 23% TgAb, 2.6% TPOAb and 3.9% TRAb. JOSLE patients with positive thyroid autoantibodies had higher frequency of anti-U1RNP antibodies than patients without these antibodies (40.9 vs. 14.5%, OR:0.25, CI:0.08-0.76, p = 0.017). Furthermore, renal/neurological/hematological involvement was less frequently observed in patients with hypothyroidism (55.6 vs. 87.5%, OR:0.18, CI:0.04-0.81, p = 0.035) and with thyroid antibodies (68.4 vs. 90.9%, OR:0.22, CI:0.06-0.82, p = 0.027) than in patients without these alterations. No association with PTPN22 polymorphism was found. In conclusion, JOSLE patients have high prevalence of subclinical hypothyroidism. The novel association of anti-thyroid antibodies with anti-U1RNP antibodies in JOSLE seems to identify a subgroup of patients with less life-threatening organ involvement.
Rheumatology Division, e Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil. lucianapc@gmail.com
Luciana
L
Parente Costa
Eloisa
E
Bonfá
Ciro D
CD
Martinago
Ricardo M
RM
de Oliveira
Jozélio Freire
JF
Carvalho
Rosa M R
RM
Pereira
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology; D002648:Child; D005260:Female; D005838:Genotype; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000235:genetics; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D054596:Protein Tyrosine Phosphatase, Non-Receptor Type 22 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011989:Receptors, Thyrotropin / Q000276:immunology; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000097:blood; D013959:Thyroid Diseases / Q000235:genetics / Q000276:immunology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D055815:Young Adult
D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D011989:Receptors, Thyrotropin; D017412:Ribonucleoprotein, U1 Small Nuclear; C006606:anti-thyroglobulin; D013972:Thyrotropin; C056658:TPO protein, human; D007453:Iodide Peroxidase; C516765:PTPN22 protein, human; D054596:Protein Tyrosine Phosphatase, Non-Receptor Type 22; D013974:Thyroxine