Renal Transplant Recipient with Concurrent COVID-19 and Stenotrophomonas maltophilia Pneumonia Treated with Trimethoprim/Sulfamethoxazole Leading to Acute Kidney Injury: A Therapeutic Dilemma

BACKGROUND Although coronavirus disease 2019 (COVID-19) manifests primarily as a lung infection, its involvement in acute kidney injury (AKI) is gaining recognition and is associated with increased morbidity and mortality. Concurrent infection, which may require administration of a potentially nephrotoxic agent, can worsen AKI and lead to poor outcomes. Stenotrophomonas maltophilia is a multidrug-resistant gram-negative bacillus associated with nosocomial infections, especially in severely immunocompromised and debilitated patients. Trimethoprim/sulfamethoxazole combination (TMP/SMX) is considered the treatment of choice but can itself lead to AKI, posing a significant challenge in the management of patients with concomitant COVID-19 and S. maltophilia pneumonia. CASE REPORT A 64-year-old male with end-stage renal disease and post renal transplant presented with severe respiratory symptoms of COVID-19 and was intubated upon admission. His renal functions were normal at the time of admission. The patient subsequently developed superimposed bacterial pneumonia with S. maltophilia requiring administration of TMP/SMX. However, TMP/SMX led to the development of AKI, which continued to worsen despite appropriate management including hemodialysis. This coincided with and most likely resulted in the patient's clinical deterioration and ultimate death. CONCLUSIONS The etiology of kidney disease involvement in patients with COVID-19 is still evolving and appears to be multifactorial. The condition can significantly worsen especially when nephrotoxic agents are given, probably due to a cumulative or synergistic effect. Great caution should be taken when administering nephrotoxic agents in the setting of COVID-19 as it can lead to adverse patient outcomes.