Renal Dysfunction as an Independent Risk Factor for Pneumocystis jirovecii Pneumonia in Immunosuppressed Patients: A Systematic Review and Meta-Analysis

Background: Pneumocystis jirovecii pneumonia remains a life-threatening opportunistic infection in immunosuppressed non-HIV patients, carrying mortality rates of 30 to 60 percent. Clinical observations in a kidney transplant program revealed that 50 to 70 percent of patients who developed PJP had CKD stage 3 or higher — far exceeding the background prevalence in the general transplant population. Despite this, no prior meta-analysis had quantified renal dysfunction as an independent risk factor for PJP. We conducted this systematic review and meta-analysis to fill that gap.
Methods: We systematically searched PubMed, Embase, and Cochrane Library through December 2024. Studies were eligible if they enrolled immunosuppressed non-HIV adults and reported either adjusted odds ratios for eGFR as a continuous variable, or mean and standard deviation of eGFR or serum creatinine in PJP and non-PJP groups. Meta-analyses used random-effects models. Pre-specified subgroup analyses compared kidney transplant recipients against non-transplant glomerular disease populations.
Results: Nine studies comprising 8,341 patients were included — 4 in kidney transplant recipients, and 5 in non-transplant glomerular disease including membranous nephropathy, lupus, and primary nephrotic syndrome.
The pooled adjusted odds ratio was 1.255, with a 95 percent confidence interval of 1.108 to 1.422, with zero percent heterogeneity, and p less than 0.001. This means each 10 milliliter per minute per 1.73 square meter decrease in eGFR is associated with a 25.5 percent increase in PJP risk.

The eGFR standardized mean difference was minus 0.936, again with zero percent heterogeneity — and critically, this was consistent across both kidney transplant recipients and non-transplant patients, with no significant subgroup difference (p = 0.602).

Serum creatinine was also significantly higher in PJP patients, with a standardized mean difference of plus 0.728 and heterogeneity of only 10.6 percent.
Conclusions: Renal dysfunction is an independent risk factor for PJP across both kidney transplant and non-transplant populations. Each 10 milliliter per minute decrease in eGFR is associated with a 25.5 percent increase in PJP risk, with zero percent heterogeneity across all analyses. Assessment of renal function should be integrated into PJP risk stratification for all immunosuppressed patients.