A Case of Graves’ Disease With Reversible Pulmonary Hypertension and Agranulocytosis

Introduction: Graves' disease (GD) is a multisystem autoimmune disorder with variable systemic manifestations. Pulmonary artery hypertension (PAH) and pancytopenia are amongst the rare complications of GD. Case Presentation: A 33-year-old, female with GD, presented to us with features of anemia, right heart failure (RHF) and recurrence of thyrotoxicosis for 1 month. She had past history significant for peritonsillar abscess due to anti-thyroid drug (ATD) induced agranulocytosis requiring their stoppage and appropriate care. On evaluation, she had relapse of hyperthyroidism with bi-cytopenia, isolated RHF and moderate PAH. Hematological work up for possible secondary causes of pancytopenia were negative. Patient was started on lithium, cholestyramine, propranolol along with Lugol's iodine and hydrocortisone. Diuretics and angiotensin-converting enzyme inhibitor therapy were also added. Following stabilization, considering the need for acute control of thyrotoxicosis; patient underwent total thyroidectomy without any untoward complications. Pathology revealed features consistent with GD and started on levothyroxine supplementation. At 2 months follow up, patient was euthyroid with resolution of PAH and pancytopenia. Discussion: Decreased production of haemopoietic cells, increased immunological destruction of cell lines and splenic sequestration are few of the mechanisms implicated in pancytopenia due to GD. Agranulocytosis as a side effect of ATD therapy is a known complication, resolving following their discontinuation. The excess of thyroid hormone related changes in cardiovascular dynamics, increased degradation of vasodilating substances in pulmonary arterial bed, endothelial dysfunction, autoimmune mechanisms, and increased expression of vasoconstrictors are few of the mechanisms implicated in pathophysiology of PAH with GD. Conclusion: This case highlights the importance of timely diagnosis of complications due to GD and establishment of early euthyroidism that leads to their resolution.