Retrospective Evaluation of Cystatin C as a Measure of Renal Function in Pediatric Hematopoietic Stem Cell Transplant Patients Receiving Foscarnet for Cytomegalovirus Reactivation

Pediatr Infect Dis J. 2024 May 1;43(5):457-462. doi: 10.1097/INF.0000000000004238. Epub 2023 Dec 28.

Abstract

Background: Cytomegalovirus (CMV) infection following allogeneic hematopoietic cell transplantation has considerable morbidity and mortality, and foscarnet is a treatment option that requires renal dose adjustment. Serum creatinine (SCr)-based estimated glomerular filtration rate (eGFR) equations are used to estimate renal function for patients receiving foscarnet, but cystatin C (cysC) has been shown as a possible alternative. Data examining cysC-based eGFR in this population is sparse. Our primary objective was to evaluate outcomes of patients treated with foscarnet dosed utilizing cysC-based eGFR versus SCr-based eGFR.

Methods: We analyzed patients on the transplantation and cellular therapies service at Memorial Sloan Kettering Kids from January 2011 to September 2021 who received allogeneic hematopoietic cell transplantation and ≥14 days of foscarnet for CMV infection. Patients with cysC-based eGFR were compared to a historical cohort of patients who only had SCr-based eGFR. Outcomes included time to CMV clearance, death or change in anti-CMV therapy. Cumulative incidence curves and cause-specific hazards model were used for analysis.

Results: In 61 analyzed patients, no differences were found between the cohorts in cumulative incidence of change in anti-CMV therapy ( P = 0.17) or death ( P = 0.69). After adjustment for multiple confounders, patients in the SCr cohort seemed to have a higher chance of CMV clearance compared with the cysC cohort, but the difference was not statistically significant (hazard ratio = 2.42, P = 0.089). Patients who received corticosteroids appeared to have lower incidence of CMV clearance ( P = 0.056).

Conclusions: We did not find differences in outcomes when dosing foscarnet using cysC versus SCr for treatment of CMV infection.

MeSH terms

  • Antiviral Agents
  • Child
  • Cystatin C / therapeutic use
  • Cytomegalovirus
  • Cytomegalovirus Infections* / drug therapy
  • Cytomegalovirus Infections* / etiology
  • Foscarnet / adverse effects
  • Foscarnet / therapeutic use
  • Hematopoietic Stem Cell Transplantation* / adverse effects
  • Humans
  • Kidney
  • Retrospective Studies

Substances

  • Foscarnet
  • Cystatin C
  • Antiviral Agents