Propylthiouracil-Induced Vasculitis With Alveolar Hemorrhage Confirmed by Clinical, Laboratory, Computed Tomography, and Bronchoscopy Findings: A Case Report and Literature Review

Abstract

Introduction: Propylthiouracil (PTU) is commonly used to treat hyperthyroidism and can induce antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Although this is a rare side effect, ANCA-associated vasculitis can progress to severe disease if its diagnosis and treatment are delayed, leading to a poor prognosis.

Case presentation: A 43-year-old woman with Graves' disease developed pulmonary vasculitis and diffuse alveolar hemorrhage (DAH) associated with ANCA against myeloperoxidase and proteinase-3 that was confirmed by computed tomography (CT) and bronchoscopy and treated with PTU. The symptoms and signs of alveolar hemorrhage were rapidly resolved after PTU withdrawal and treatment with corticosteroids. After 6 months of follow-up, the patient maintained complete ANCA-negative clinical remission status, as confirmed by normal CT and bronchoscopy findings. To our knowledge, this is the first documented case of bronchoscopic comparison of PTU-induced DAH before and after steroid treatment.

Conclusions: Patients treated with PTU should be closely monitored and followed up, even if the drug has been used for several years. When patients develop progressive dyspnea with alveolar opacities on chest imaging that cannot be explained otherwise, alveolar hemorrhage should be an important differential diagnosis while investigating the case. Early diagnosis and prompt discontinuation of the PTU treatment are essential for improving patient outcomes.

Keywords: Antineutrophil Cytoplasmic Antibody (ANCA); Graves’ Disease; Thyroid Disease; Vasculitis.

Figure 1.. A, High-resolution chest computed tomography performed at admission, revealing diffuse bilateral alveolar infiltrates and ground-glass opacification, predominantly in the middle and lower lung fields, consistent with pulmonary hemorrhage; B, after 2 weeks of PTU withdrawal and steroid treatment, high-resolution chest computed tomography showed improvement in alveolar infiltrates and ground-glass opacity; C, after 6 weeks of PTU withdrawal and steroid treatment, high-resolution chest computed tomography showed restoration of the lung parenchyma, with the alveolar infiltrates and ground-glass opacity completely disappeared.

Figure 2.. A, bronchoscopic image showing needlepoint hemorrhage, with partial fusion in the submembrane along the left main bronchus, and spreading to the opening of the left upper lobe (before treatment); B, bronchoscopic image showing no hemorrhage (6 weeks after the treatment).