A case report of IgG4-related respiratory disease with pleural effusion and a literature review

Abstract

Rationale: IgG4-related respiratory disease (IgG4-RRD) is a chronic autoimmune disease that affects the respiratory system and organs outside the respiratory system. This study explored the diagnosis and treatment of a case of IgG4-RRD with unilateral pleural effusion diagnosed using medical thoracoscopy, and provides an associated literature review. This report summarizes the clinical characteristics of IgG4-RRD involving the pleura to improve the diagnosis of this disease.Patient concerns: A 39-year-old man presented with a 2-week history of cough and chest tightness. Both physical examination and imaging supported the presence of left pleural effusion.Diagnosis: Medical electronic thoracoscopy was performed to obtain a pleural biopsy, which showed lymphoplasmacytic infiltration, 40 IgG4+ plasma cells per High Power Field (HPF) on microscopy, IgG4/IgG ratio >50%, phlebitis obliterans, and storiform fibrosis. The final diagnosis was IgG4-RRD. Interventions and outcomes:The patient was treated with methylprednisolone, after which his symptoms improved, and he was discharged. Oral hormone therapy was continued outside the hospital. After 4 months, the patient returned to the hospital and his condition had improved significantly.Lessons: Pleural involvement in IgG4-RRD is rare, and its diagnosis depends on pleural biopsy. Thoracoscopy usually reveals pleural thickening, pleural nodules, and milky white plaques.

IgG4-related diseases involving pleura: a case report and literature review

“…In IgG4-PL patients, it is typically observed that CRP levels are within normal range. However, in the cases we analyzed, 10 individuals demonstrated a mild increase in CRP levels (8,13,18,20,21,27,28,33,36,37). It is important to highlight the contrast between IgG4-PL and conditions such as ANCA associated vasculitis and multicentric Castleman disease (MCD) when considering the levels of inflammatory markers like CRP.…”