A patient receiving long-term carbimazole developed microscopic polyangiitis with diffuse alveolar hemorrhage and coexistent antiphospholipid syndrome, with rapid stabilization following plasmapheresis.
The report authors described a 29-year-old female patient with hyperthyroidism treated with carbimazole for 15 years who presented with acute-onset hemoptysis and type 1 respiratory failure. Imaging with high-resolution computed tomography showed ground-glass opacities consistent with diffuse alveolar hemorrhage, and laboratory evaluation confirmed myeloperoxidase–antineutrophil cytoplasmic antibody–associated vasculitis. Additional findings included elevated immunoglobulin M (IgM) anticardiolipin antibodies consistent with antiphospholipid syndrome (APS).
Disease activity, measured using the Birmingham Vasculitis Activity Score (BVAS), was 14, reflecting pulmonary, renal, and systemic involvement. Renal evaluation showed microscopic hematuria and a protein-creatinine ratio of 0.40. Biopsy findings included segmental tuft necrosis with basement membrane disruption and moderate-intensity granular immune deposits on immunofluorescence, indicating an immune-complex–mediated variant reported in approximately 25% of antineutrophil cytoplasmic antibody–associated vasculitis cases.
The APS classification score was 10, based on high-titer IgM anticardiolipin antibodies (130 MPL) and obstetric history. The coexistence of vasculitis and APS influenced treatment decisions because of competing risks of hemorrhage and thrombosis.
Carbimazole was discontinued at presentation. The patient received pulse methylprednisolone followed by intravenous cyclophosphamide (500 mg every 2 weeks for six doses over a period of 14 weeks). Five sessions of plasmapheresis were performed using full plasma volume exchange with albumin and fresh frozen plasma as replacement fluids. Following treatment, repeat imaging showed near-complete resolution of pulmonary hemorrhage.
At 6 months, the patient remained in clinical and radiologic remission without recurrence of hemoptysis or renal dysfunction. Carbimazole was reintroduced at 10 mg without recurrence of vasculitis, and the patient maintained a euthyroid state. Aspirin 75 mg was initiated for APS, while systemic anticoagulation was deferred because of the bleeding risk and absence of prior thrombosis.
The report authors described this presentation as a “triple-hit” involving vasculitis, thrombosis, and immune-complex deposition and noted the management challenge as a “therapeutic tightrope.”
“the rapid initiation of plasmapheresis is a decisive intervention […] serving as an essential bridge that allows the pulmonary system to stabilize before long-term anticoagulation can be safely introduced,” wrote lead report author P. Thulasinadh, MD, MBBS, of the Department of General Medicine at the Ballari Medical College and research Centre in India, and colleagues.
Because the case report described a single patient, the results could limit generalizability. Additional immunologic characterization, including electron microscopy and immunoglobulin subclass analysis, wasn't performed as a result of institutional resource constraints.
The researchers reported no conflicts of interest.
Source: Cureus
