Unusual Presentation of Immune Reconstitution Inflammatory Syndrome (Iris)

Abstract

INTRODUCTION:Pneumocystis jirovecii (PJP) can cause a life-threatening opportunistic infection in patients with HIV, especially in those not treated with HAART and a CD4 count less than 200 cells/mcL. Diagnosis of PJP in HIV patients is typically made with bronchoscopy with a very high diagnostic yield of bronchoalveolar lavage (BAL). IRIS describes the paradoxical worsening of a preexisting infection following HAART initiation (1). We present a case of an HIV patient with PJP-related IRIS who presented with an atypical chest radiograph and a negative BAL. CASE PRESENTATION:A 48-year-old man with HIV presented to the ED for a 2-week history of subjective fevers, chills, poor appetite, progressively worsening dyspnea, non-productive cough, and pleuritic chest pain associated with intermittent myalgias. He had recently started HAART (bictegravir, emtricitabine, and tenofovir alafenamide) ten days prior after presenting with oropharyngeal candidiasis; at that time his chest radiograph (xray) was normal and he denied respiratory symptoms. He had been prescribed prophylactic trimethoprim-sulfamethoxazole for PJP prophylaxis but was non-compliant. The patient was hemodynamically stable on presentation, temperature was 39 C, and oxygen saturation of 95% on room air. He was tachypneic with a respiratory rate of 26, and his lungs were clear. Initial workup showed a WBC of 4.6*10^3 /mcL (78% neutrophils, 17% lymphocytes) with absolute lymphopenia of 0.75*10^3 /mcL. His CD4 count was 85 cells/mcL with a viral load of 3360 copies/ mcL. LDH was elevated at 1281 units/L. His initial blood gas was 7.52/22/58 showing respiratory alkalosis and hypoxemia. Chest xray showed bilateral coalescing upper lung opacities. He was started on trimethoprim-sulfamethoxazole and prednisone for suspected PJP pneumonia along with antibiotic coverage of community-acquired pneumonia. Bronchoscopy showed normal bronchial mucosa with minimal secretions. BAL specimens were negative for bacterial, fungal, and mycobacterial growths. Transbronchial biopsies (TBBx) of the left upper lobe revealed PJP on GMS stain.DISCUSSION: We present a case of an HIV patient who developed acute hypoxemic respiratory failure from PJP soon after starting HAART despite a normal chest x-ray 2 weeks prior. The rapid worsening after initiation of HAART is consistent with IRIS. A Spanish observational study showed that PJP-related IRIS is uncommon involving only six cases of IRIS out of 123 (4.9%) (2).Our patient's chest radiograph atypically showed bilateral coalescing upper lung opacities. Typical chest radiographs in PCP show bilateral diffuse or perihilar symmetric interstitial changes that can be reticular, ground glass, or granular (3).CONCLUSIONS: Given the high yield of BAL in HIV patients, many physicians defer TBBx in these patients. The negative BAL in our patient may suggest a need for performing TBBx in patients with HIV presenting with IRIS.