Determining the threshold for azathioprine use in recurrent diffuse alveolar hemorrhage in idiopathic pulmonary hemosiderosis

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease that affects both children and adults and is an underreported and under-recognized etiology of diffuse alveolar hemorrhage (DAH). 1 Saha BK. Idiopathic pulmonary hemosiderosis: a state of the art review. Respir Med. 2020; 176106234 PubMed Google Scholar Although the exact pathogenesis of DAH in IPH is uncertain, several hypotheses have been proposed. 2 Saha BK Chong WH Saha S et al. Proposed pathogenesis of diffuse alveolar hemorrhage in idiopathic pulmonary hemosiderosis. Lung. 2022; ([cited 2022 Mar 10])https://doi.org/10.1007/s00408-022-00523-4 Crossref PubMed Scopus (6) Google Scholar IPH is considered an immunologic disease with an expected response to corticosteroid (CS) therapy. However, no randomized prospective trials have assessed the efficacy of CS or other immunosuppressive therapy. In general, CS is the backbone of treatment in IPH except in patients with coexisting celiac disease, where strict avoidance of gluten could be potentially curative. 3 Saha BK Datar P Aiman A et al. Comparative analysis of adult patients with idiopathic pulmonary hemosiderosis and lane-hamilton syndrome: a systematic review of the literature in the period 1971-2022. Cureus. 2022; 14 ([cited 2022 Mar 26]. Available from:)https://www.cureus.com/articles/89819-comparative-analysis-of-adult-patients-with-idiopathic-pulmonary-hemosiderosis-and-lane-hamilton-syndrome-a-systematic-review-of-the-literature-in-the-period-1971-2022 Google Scholar Numerous other immunosuppressive pharmacologic agents have been used for IPH by physicians around the world without any consensus. We have presented a treatment algorithm for IPH in the past representing authors' personal views than evidence-based data. 4 Saha BK Milman NT. Idiopathic pulmonary hemosiderosis: a review of the treatments used during the past 30 years and future directions. Clin Rheumatol. 2021; 40: 2547-2557 Crossref PubMed Scopus (18) Google Scholar Nonetheless, such an algorithm could provide much-needed guidelines for clinicians challenged with treating rare patients with this orphan disease.