The challenge of using the rheumatoid arthritis diagnostic criteria in clinical practice

The current status of anti-citrullinated protein antibodies and citrullinated protein-reactive B cells in the pathogenesis of rheumatoid arthritis

Anti-citrullinated protein antibodies are a hallmark of rheumatoid arthritis. It is widely acknowledged that the presence of ACPAs is the result of the interaction of genes, the environment and epigenetic modifications. The mechanism by which the factors, especially citrullination and ACPA glycosylation, affect ACPAs is still unclear. In this article, we review the presence of the ACPAs in RA and their relationship with clinical manifestations. The pathogenicity of ACPAs and B cells in RA was also summarized. A growing body of evidence has shown that ACPA-positive patients have more serious bone erosion and destruction and poor clinical prognosis than ACPA-negative patients. Recently, with the direct study of citrullinated protein-reactive B cells, their role in the development of rheumatoid arthritis has been further understood. It indicates that further understanding of the mechanism of ACPAs and CP-reactive B cells would beneficial in the prevention and treatment of RA.

Multilocular thymic cyst in a patient with preclinical rheumatoid arthritis: A case report

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Inflammatory conditions cause multilocular thymic cyst.

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Causes of the inflammation include autoimmune diseases or malignant tumors.

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Evaluating the cause of inflammation in multilocular thymic cyst is essential.

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First reported multilocular thymic cyst with preclinical rheumatoid arthritis.

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Early treatment of rheumatoid arthritis prevents irreversible disability.

Introduction

Multilocular thymic cyst (MTC) is a rare condition of an acquired multilocular cystic lesion caused by inflammation and often associated with autoimmune diseases or malignant tumors. We present a patient with MTC and asymptomatic rheumatoid arthritis (RA), which is termed preclinical RA.

Presentation of case

A 60-year-old man underwent a computed tomography scan, which revealed an 8.5 cm multilocular cystic lesion in the anterior mediastinum. The tumor had a lower intensity on T1-weighted imaging and a higher intensity on T2-weighted imaging. The imaging did not only suggest an MTC, but also the possibility of a thymoma with cystic degeneration, or lymphoma. We performed an extended thymectomy via median sternotomy. The lesion was diagnosed as MTC based on histopathological findings. Laboratory tests were performed for the purpose of screening for autoimmune diseases. He was diagnosed with preclinical RA, since the anti-cyclic citrullinated peptide antibody (ACPA) was positive.

Discussion

Specificity of ACPA is recorded in over 90% of patients with RA; ACPA is positive in about 40% of patients with preclinical RA. As patients with preclinical RA are more likely to develop RA, careful follow-up is required. Early diagnosis and treatment of RA can prevent destruction of joints, thereby preventing irreversible disability.

Conclusion

In patients with MTC, evaluating the cause of the inflammation, such as autoimmune diseases, is essential. Further studies are required to investigate the relationship between MTC and preclinical RA.