Interstitial lung disease with congenital erythrocytosis

Abstract

A 45-year-old male weaver, smoker, known case of interstitial lung disease with cor pulmonale on long-term oxygen therapy diagnosed 6 months ago who is on tapering doses of oral steroids presented to our tertiary care teaching hospital with complaints of worsened shortness of breath, cough with expectoration and fever for the past 4 days. The patient had headache, dizziness for the past 6 months. On examination, he was febrile with plethoric facies, conjunctival congestion and digital clubbing were noted. Tachycardia and tachypnoea were noted. Haemoglobin saturation on pulse oximetry was 75% while breathing on room air, 94% with 0.4 fraction of inspired oxygen. On respiratory system examination, bilateral infraaxillary crepts were present, jugular venous pressure was elevated. Remaining systemic examination was unremarkable. Investigations revealed elevated haemoglobin, elevated leucocyte count with neutrophilic leucocytosis, raised packed cell volume and red cell count. Platelet count 1.67 × 105/mm3, erythrocyte sedimentation rate 4 mm at the end of the first hour. Computed tomography (CT) of the chest (plain) showed inter and intralobular septal thickening with honeycombing in the bilateral lower lobes predominantly features suggestive of interstitial lung disease. Ultrasonography of the abdomen showed no hepatosplenomegaly. Two dimensional echocardiography was suggestive of corpulmonale. As patient had hyperviscosity symptoms due to polycythaemia and no improvement in haemoglobin with supplemental oxygen for the past 6 months, patient was further evaluated for alternate cause of polycythaemia. Serum erythropoietin (Epo) levels were normal. Arterial oxygen tension at which oxygen saturation was 50% (P50) was 28 mm Hg. Epo gene receptor mutation was positive suggestive of congenital erythrocytosis. Patient was advised long-term oxygen therapy and regular therapeutic phlebotomy to maintain haemoglobin levels and was discharged in a haemodynamically stable condition.

Keywords

• congenital erythrositosis
• interstetial lung disease
• polycythemia