The onset of antineutrophil cytoplasmic antibody-associated vasculitis immediately after methimazole was switched to propylthiouracil in a woman with Graves' disease who wished to become pregnant

Rheumatic and autoimmune thyroid disorders: a causal or casual relationship?

A number of dysfunctions may affect the thyroid gland leading either to hyper- or hypothyroidism which are mediated by autoimmune mechanisms. Thyroid abnormalities may represent an isolated alteration or they may be the harbinger of forthcoming disorders as is the case of well-characterized polyendocrine syndromes. Also, they may precede or follow the appearance of rheumatic manifestations in patients affected with connective tissue diseases or rheumatoid arthritis. The mechanisms by which autoimmune thyroid disorders may be linked to systemic autoimmune diseases have not been fully unraveled yet, however alterations of common pathways are suggested by shared genetic variants affecting autoantigen presentation and regulation of the immune response. On the other hand, the higher prevalence of autoimmune thyroid disorders over rheumatic diseases compels the chance of a mere causal concomitancy in the same patient. The aim of our paper is to provide an overview of available data on thyroid involvement in different rheumatic diseases and to go over the main rheumatic manifestations in the context of autoimmune thyroid diseases.

Trojan horses: drug culprits associated with antineutrophil cytoplasmic autoantibody (ANCA) vasculitis

PURPOSE OF REVIEW

Antineutrophil cytoplasmic autoantibody (ANCA) vasculitis is a systemic autoimmune disease resulting in small-vessel inflammation caused by pathogenic autoantibodies directed against proteinase 3 or myeloperoxidase. Legal drug culprits have been implicated as causative agents in secondary forms of disease, and a recent burst of reports also implicate levamisole-adulterated cocaine as a culprit.

RECENT FINDINGS

Here, we briefly discuss all drug culprits associated with ANCA vasculitis and then focus on clinical, serologic, therapeutic and mechanistic aspects of four main drug culprits receiving attention of late, namely hydralazine, minocycline, propylthiouracil (PTU) and levamisole-adulterated cocaine.

SUMMARY

Hydralazine, minocycline, propylthiouracil and levamisole-adulterated cocaine use should be closely considered in any patient where ANCA vasculitis is entertained given the wide use of these drugs in the community. Furthermore, medical practitioners should test urine for the presence of cocaine in any patient with presumed ANCA vasculitis, and if positive, then urine should also be tested for levamisole. Clinical features can be severe requiring not only drug cessation and supportive care, but also immunosuppression, plasma exchange in severe cases and dialysis as needed. Clinical trial investigators should strongly consider excluding patients with drug-induced forms of disease and mechanistic inroads are greatly needed in these secondary forms of disease to help elucidate the underlying cause and pathogenesis of ANCA vasculitis.

Therapy of endocrine disease: antithyroid drug use in early pregnancy and birth defects: time windows of relative safety and high risk?

BACKGROUND

Antithyroid drugs (ATDs) may have teratogenic effects when used in early pregnancy.

OBJECTIVE

To review the association between the time period of ATD exposure in early pregnancy and the development of birth defects.

METHODS

We identified publications on birth defects after early pregnancy exposure to the ATDs methimazole (MMI; and its prodrug carbimazole (CMZ)) and propylthiouracil (PTU). Cases of birth defects after ATD treatment had been initiated or terminated within the first 10 weeks of pregnancy were identified and studied in detail.

RESULTS

A total of 92 publications were read in detail. Two recent large controlled studies showed ATD-associated birth defects in 2-3% of exposed children, and MMI/CMZ-associated defects were often severe. Out of the total number of publications, 17 included cases of birth defects with early pregnancy stop/start of ATD treatment, and these cases suggested that the high risk was confined to gestational weeks 6-10, which is the major period of organogenesis. Thus, the cases reported suggest that the risk of birth defects could be minimized if pregnant women terminate ATD intake before gestational week 6.

CONCLUSION

Both MMI and PTU use in early pregnancy may lead to birth defects in 2-3% of the exposed children. MMI-associated defects are often severe. Proposals are given on how to minimize the risk of birth defects in fertile women treated for hyperthyroidism with ATDs.