Seronegative Rheumatoid Arthritis Secondary to Immune Checkpoint Inhibitor in a Renal Cell Carcinoma Patient Encountered in a Rural Community-Based Rheumatology Clinic: A Case Report.

Immune checkpoint inhibitors (ICIs) are a widely used class of cancer immunotherapy. Those drugs have improved the treatment of cancer since its introduction in the 2000s. Nivolumab is an ICI that can be used for previously untreated renal cell carcinoma. Immune-related adverse events (irAEs) are a type of adverse event of immunotherapy that is associated with an overreactive immune system. We report a case of a 69-year-old Caucasian man with stage IV renal cell carcinoma who presented to a rural community-based rheumatology clinic referred by his oncologist, after starting to develop morning stiffness for at least three hours, joint swelling, warmth, and erythema five months after starting immunotherapy with nivolumab. The patient was diagnosed with seronegative rheumatoid arthritis secondary to ICIs and required a higher dose of prednisone (up to 40 mg per day) with methotrexate to achieve remission. With the widespread availability of ICIs, rheumatologic irAEs can be encountered in a rural community-based practice. Practicing physicians taking care of cancer patients need to be aware of the adverse effect of ICIs.

Reversible Autoimmune Cardiomyopathy Secondary to a Vaccine-Induced Multisystem Inflammatory Syndrome.

The Dominican government started an early booster protocol, including a heterogeneous vaccination sequence needed based on availability. We report a case of a 25-year-old male who presented with jaundice, and vomiting for 6 days, associated with maculopapular rash (Mucocutaneous features), elevated pro-B-type natriuretic peptide (pro-BNP), erythrocyte sedimentation rate (ESR), transaminitis (> 1000 U/L), thrombocytopenia, echocardiogram evidenced stigmata of heart failure after his third dose of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. He was started on steroids and immunoglobulin therapy for multisystemic organ failure syndrome. A significant improvement was noticed, then was discharge; in the post-discharge clinic, he was asymptomatic, inflammatory markers improved, and the echocardiogram showed a recovered ejection fraction. An accurate anamnesis, including a proper chronologic gathering of the events, is essential to recognize a vaccine-multisystem inflammatory syndrome; its prompt assessment and therapy would directly improve the outcome.