Is the updated Schwartz formula appropriate for assessing renal function prior to hematopoietic stem cell transplantation?

Abstract

Assessing renal function is an integral part of evaluating pediatric patients for hematopoietic stem cell transplantation (HSCT). The most accurate method is DTPA-Tc-(99m) GFR testing. However, it is costly and time consuming. The Schwartz formula, which was recently updated, represents an inexpensive and readily available alternative. We assessed agreement between the original and updated formula and DTPA-Tc-(99m) in 107 patients who were being evaluated for HSCT. Agreement between both formulas and DTPA-Tc-(99m) was poor, although the updated formula performed marginally better. The Schwartz formulas do not appear to be accurate enough to be used for pre-transplant kidney function evaluation.

Pharmacokinetics and Pharmacodynamics of Continuous-Infusion Meropenem in Pediatric Hematopoietic Stem Cell Transplant Patients

“…Among our patients aged 1 to 16 years, the median and IQR of CL CR estimated by means of the original Schwartz equation (37) were similar to those observed previously by other authors in the same setting (38,39). Overall, nonlinear regression documented a good sigmoidal relationship between CL CR estimates and CL M (r 2 ϭ 0.733).…”

Small vessels, big trouble in the kidneys and beyond: hematopoietic stem cell transplantation–associated thrombotic microangiopathy

“…Although nuclear GFR remains the "gold standard" for renal assessment in patients after HSCT, it is expensive, invasive, and requires exposure to radiation, necessitating the evaluation of alternative measures, such as cystatin C-based GFR. 62,63 Finally, long-term screening for proteinuria in patients with a history of TA-TMA may identify those at greatest risk of CKD and associated complications and "open the door" for the initiation of ACEI therapy. 36,86 It is important to acknowledge that the renal and cardiovascular sequelae of CKD and TA-TMA contribute significantly to shortand long-term morbidity and mortality.…”

“…13 Others have also shown that creatininebased GFR estimation is inferior to nuclear GFR before HSCT. 62 Cystatin C, a recently introduced non-muscle-based marker of kidney function measured with a single blood test, may prove to be a useful indicator of GFR in the future, but prospective data validating this approach after HSCT are unavailable. 62,63 Second, the inclusion of lactate dehydrogenase (LDH) as a diagnostic criterion presumes that all centers check this parameter on a routine basis.…”

“…62 Cystatin C, a recently introduced non-muscle-based marker of kidney function measured with a single blood test, may prove to be a useful indicator of GFR in the future, but prospective data validating this approach after HSCT are unavailable. 62,63 Second, the inclusion of lactate dehydrogenase (LDH) as a diagnostic criterion presumes that all centers check this parameter on a routine basis. 2 An otherwise well-designed study of acute kidney injury (AKI) after HSCT by Hingorani et al was accordingly unable to assess for TA-TMA because LDH was not measured at their center.…”

“…18 However, as mentioned earlier, creatinine-based definitions of kidney injury can underestimate the prevalence of AKI (Table 3) and CKD (Table 4) in this population, necessitating the validation of novel markers of injury and kidney function. 62,63,67 …”