Frequency of abnormal thyroid function tests in Kuwaiti Arabs with autoimmune diseases.

OBJECTIVES: The purpose of this study was to examine the frequencies of abnormal thyroid function tests and serum thyroid autoantibodies in healthy Kuwaitis and those with autoimmune diseases. SUBJECTS AND METHODS: Serum concentrations of sensitive thyrotropin, and free thyroxine were measured in 577 apparently healthy controls, 177 patients with rheumatoid arthritis (RA), 60 with systemic lupus erythematosus (SLE) and 25 with primary Sjogren's syndrome (pSS) using the immunochemiluminescent assay method on IMMULITE 1000. Serum microsomal and thyroglobulin autoantibodies were also measured by passive hemagglutination assay. For analysis of the thyroid function tests, the subjects were classified into five categories: normal, subclinical hypothyroidism, overt hypothyroidism, euthyroid sick syndrome and biochemical hyperthyroidism. RESULTS: Subclinical hypothyroidism was seen in 1.7% of healthy controls, 10.2% of RA, 13.3% of SLE, and 16% of pSS patients. Among RA patients, the frequency of subclinical hypothyroidism in females (11.4%) was significantly higher than among males (5.4%; p < 0.01). In SLE and pSS patients, all those with subclinical hypothyroidism were females. Overt hypothyroidism was seen in 1.4% of controls, 10.2% of RA, 8.3% of SLE, and 4% of pSS patients. Biochemical hyperthyroidism was seen in 0.2% of controls, 4.5% of RA, 5% of SLE and none of pSS patients. The euthyroid sick syndrome was seen in 0.4% of controls, 13.6% of RA, 16.7% of SLE and in none of pSS patients. Thyroid autoantibodies were present in 3.1% of controls, 12.4% of RA, 18.3% of SLE, and 12% of pSS patients. CONCLUSION: Our data show that abnormal thyroid function tests and thyroid autoantibodies occur frequently in Kuwaitis with autoimmune diseases. Therefore, ordering these tests in these diseases is recommended.

Serum concentrations of cardiac troponin-I in patients with rheumatoid arthritis, systemic lupus erythematosus, primary Sjogren's syndrome and Graves' disease.

INTRODUCTION: Some reports in the literature suggest that cardiac troponin-I (cTnI) is falsely elevated in patients with seropositive rheumatoid arthritis (RA) because of the presence of rheumatoid factor (RF). But, there are no reports in the literature on cTnI concentrations in other autoimmune diseases. We therefore decided to measure the serum concentrations of cTnI in patients with seropositive and seronegative RA, systemic lupus erythematosus (SLE), primary Sjogren's syndrome (pSS) and Graves' disease (GD), in order to find out if this cardiac marker is falsely elevated or not. METHODS: Serum samples were drawn from 50 patients with seropositive RA, 50 patients with seronegative RA, 50 patients with SLE, 20 patients with pSS and 15 patients with GD. We measured cTnI levels using the Beckman Access Immunoassay System in these serum samples. RESULTS: Of the 50 patients with seropositive RA, five had cTnI levels higher than 0.1 ng per ml (the diagnostic value for myocardial infarction in our hospital laboratory), while none of the patients with seronegative RA, SLE, pSS, or GD had levels above this value. Furthermore, univariate regression analysis showed a positive association (r equals 0.35, p-value equals 0.02) between cTnI and RF in patients with seropositive RA. CONCLUSION: Using the Beckman Access Immunoassay System for cTnI quantification, it was found that some patients with seropositive RA had falsely-elevated cTnI, while none of the patients with seronegative RA, SLE, pSS, or GD had falsely-elevated cTnl.

Angiotensin-converting enzyme gene polymorphism in Kuwaiti patients with systemic lupus erythematosus.

OBJECTIVE: To investigate the frequency of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism genotypes in patients with systemic lupus erythematosus (SLE), and to study the correlation between I/D polymorphism of the ACE gene and the clinical manifestations of SLE, especially vascular involvement, lupus nephritis and disease severity. METHODS: The frequency of ACE gene I/D polymorphism genotypes was determined in 92 patients with SLE from Kuwait, and compared to that in 100 ethnically matched healthy controls using the polymerase chain reaction. RESULTS: The distribution of ACE I/D polymorphism and allele frequencies in SLE patients was not significantly different from controls. Further analyses of SLE patients showed that there was a significant association between DD genotype and Raynaud's phenomenon (p=0.008, odd ratio=5.4, 95% confidence interval: 1.6-18.6). However, there was no significant association between the ACE genotype and lupus nephritis or disease severity. CONCLUSION: No difference was found between the distribution of the ACE genotype in SLE patients and the general pop-ulation in Kuwait. However, the presence of the DD genotype may confer susceptibility to the development of vascular morbidity.