COEXISTING AUTOIMMUNE HAEMOLYSIS AND PNEUMOCYSTIS JIROVECII PNEUMONIA IN AN ELDERLY COPD PATIENT: A CASE REPORT

Abstract

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening opportunistic infection, mostly seen in individuals with overt immunosuppression, such as those living with HIV/AIDS. However, recent trends show increasing incidence in individuals without classical risk factors, prompting the need for broader clinical awareness. We present a complex and ultimately fatal case of PCP in an elderly man with chronic obstructive pulmonary disease (COPD), whose clinical course was complicated by newly diagnosed autoimmune haemolytic anaemia (AIHA).The patient, a 72-year-old man, arrived with progressively worsening breathlessness, fatigue, and pallor, initially attributed to a COPD exacerbation. He had no history of immunosuppressive therapy, HIV, or known immunodeficiency. However, laboratory investigations revealed severe anaemia, and a positive Direct Coombs Test confirmed AIHA. A chest CT scan raised concern for a complex pulmonary infection in an already compromised lung with findings not typical of PCP alone, but possibly exacerbated by the underlying COPD and emerging immune dysfunction from AIHA. Ultimately, microscopic examination of induced sputum stained with Giemsa and toluidine blue O confirmed P. jirovecii infection. Although, trimethoprim-sulfamethoxazole and corticosteroids were promptly initiated, the patient succumbed to progressive respiratory failure within six days. This case underscores the importance of considering PCP in non-HIV patients, particularly those with chronic lung disease and immune dysfunction. Although rare, AIHA in COPD can further weaken immune defences, heightening the risk of severe infections. The diagnostic challenge posed by clinical overlap with bacterial pneumonia and tuberculosis in non-HIV PCP underscores the need for early empirical treatment, prompt recognition, and targeted therapy to improve outcomes.