Introduction:
Kidney transplant recipients (KTRs) are predisposed to the greatest risk of opportunistic infections in the first one to six months post-transplantation period. Though the incidence of Pneumocystis Jirovecii pneumonia (PCP) has reduced with trimethoprim-sulphamethoxazole (TMP+ SMX) prophylaxis to 2 to 5%, its occurrence beyond the first year has been rarely reported. Some studies have reported an incidence of 0.4-0.8% of late-onset PCP with occurrence up to 13-24 years after kidney transplantation. The use of immunosuppressant drugs, such as glucocorticoids, calcineurin inhibitors, mycophenolate mofetil, anti-rejection therapy, old age, and Cytomegalovirus co-infection have all been described as risk factors for PCP infection.
Methods:
Here, we describe a case report of a 53-year-old gentleman, who developed PCP and Klebsiella pneumonia, only on maintenance immunosuppression, 22 years after a renal transplant.
Results:
Mr. B is a live-related kidney transplant recipient, 22 years ago, on double immunosuppression with prednisone 5 milligrams once daily and mycophenolate mofetil 360 milligrams thrice daily, with normal allograft function. He presented to the nephrology OPD with complaints of high-grade fever for 7 days along with cough and dyspnoea of 3 days duration. A recent history of air travel 2 weeks prior to the onset of the symptoms was present.
On examination, he was febrile, tachypnoeic, tachycardic, hypoxic requiring 2 liters per minute of oxygen, and had diffuse fine crepts on lung auscultation. Laboratory investigations revealed normal white cell count and normal renal and liver function tests with a bland urine routine examination. C-reactive protein levels were elevated. In suspicion of a lung parenchymal infection, a Computed tomography (CT) scan of the chest was done which revealed diffuse ground glass opacities involving both lung parenchyma with sub-pleural sparing, without any features of consolidation, effusion, nodules, or lymph nodes. An abdominal ultrasound was normal. Screening for COVID-19 and influenza infection was negative. A bronchoscopy with alveolar lavage (BAL) was done, which revealed the findings of a multi-drug resistant Klebsiella pneumonia (OXA 48+ NDM+ Klebsiella pneumonia Carbapenemase) and positive Pneumocystis Jirovecii polymerase chain reaction(PCR).
Immunosuppression was modified with the reduction of mycophenolate mofetil (360 mg on alternate days) and the addition of azathioprine 50 mg once daily. Prednisolone was further increased to 15 mg per day. He was given ceftazidime-avibactam with aztreonam for 7 days and TMP+SMX (15-20 mg/kg) for the next 21 days, with a tapering course of steroids. He improved clinically and was discharged with normal room air saturation after 10 days of hospital stay. In the subsequent outpatient follow-up, his immunosuppression was de-escalated to azathioprine and prednisolone, with the withdrawal of mycophenolate mofetil and his renal functions have remained normal.
Conclusions:
A constant low-dose maintenance immunosuppression can still substantially increase the risk of late onset PCP in KTRs, even though universal prophylaxis with TMP-SMX and long-term minimization of maintenance immunosuppressive regimens have significantly decreased the incidence of PCP. A later onset, milder atypical version of PCP has superseded the early, life-threatening illness seen in the initial transplantation period.
In our transplant recipient , the concurrent findings of PCP and a multi-drug resistant Klebsiella strain, nearly 22 years after transplantation only on double immunosuppression, raises serious concern about the overall immunocompromised status.
This is most likely due to the higher dosage of mycophenolate mofetil (360 mg TDS) which the recipient was on, even two decades after transplantation. In our experience and review of literature from the Indian subcontinent , this is the first reported case of late-onset PCP, 22 years after transplantation. This case report emphasizes the role of early detection of disease, timely reduction in immunosuppression, and appropriate treatment for a good outcome.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.