Role of Urinary Beta 2 Microglobulin and Kidney Injury Molecule-1 in Predicting Kidney Function at One Year Following Acute Kidney Injury

Abstract

Background: There is only limited information on the utility of urinary biomarkers in predicting long-term kidney function following acute kidney injury (AKI). The current study assessed whether urinary beta 2 microglobulin/creatinine (B2M/creat) and kidney injury molecule-1/creatinine (KIM-1/creat) ratios, measured in the early recovery phase of AKI, are predictive of kidney function at one year. Methods: This is a prospective study done in a tertiary care centre in South India, from March 2017 to December 2018. Adult patients who survived an episode of AKI were followed up for one year (n=125). B2M/creat and KIM-1/creat ratio were measured at two weeks and three months following AKI. Results: In the AKI survivors, the B2M/creat ratio at 2 weeks [18.3mg/g (IQR 2.3, 52.9)] and KIM-1/creat ratio [1.1 µg/g (IQR 0.5, 4.0) at two weeks were higher compared to healthy controls [B2M/creat ratio 0.35 mg/g (0.17,0.58) and KIM-1/creat ratio 0.40 µg/g (0.23,1.00); P=<0.001]. After adjusting for covariates, the eGFR and urinary B2M/creat ratio at two weeks following AKI were predictive of eGFR at one year (P<0.001). KIM-1/ creat ratios were not predictive of eGFR at one year. A urinary B2M/creat ratio of 10.85 at two weeks following AKI had an 85.5% sensitivity (95% CI 74, 93) and 64.3% (95% CI 53, 75) specificity to predict CKD at one year. An eGFR cutoff of 60 mL/min/1.73 m 2 at two weeks had a sensitivity of 81.8% (95% CI 69, 90) and specificity of 71.4% (95% CI 60, 81) for predicting CKD. The presence of either one criteria (urinary B2M/creat ratio >10.85 (mg/g) or eGFR <60 mL at two weeks) had a sensitivity of 100% (95% CI 94%, 100%) in predicting CKD at one year. Conclusion: An eGFR <60 mL/min/1.73m 2 and elevated urinary B2M/creat ratio at two weeks following AKI is predictive of low eGFR at one year. Urinary KIM-1/creat ratios do not predict CKD progression.

Proficient Novel Biomarkers Guide Early Detection of Acute Kidney Injury: A Review

“…These characteristics have made blood B2M a suitable marker for evaluating renal function in AKI and CKD. Urinary B2M levels rise early during the course of nephrotoxicity mediated AKI in rat models and revert to normal during the healing phase [ 80 ].…”

Urinary Beta-2-Microglobulin and Late Nephrotoxicity in Childhood Cancer Survivors

“…The majority of studies conducted so far have looked at serum b2M rather than urine concentrations [5,18]. Most of them pointed to elevated β2M level in patients after chemotherapy with nephrotoxic agents and emphasized its high utility in detecting chemotherapy-induced acute kidney injury [14,24]. On the other hand, there are very limited data on the utility of urinary β2M in diagnosing the onset of CKD associated with anticancer treatment.…”

The Perspectives of Biomarkers in Predicting the Survival of the Renal Graft

“…The cutoff point for urinary β2MG for the prediction of positive DMSA (technetium Tc 99m dimercaptosuccinic acid) scan was 0.8 mg, but it was not enough sensitive (40.9%) and specific (84.1%) to be used as a diagnostic marker for the prognosis of renal injury (51). Recently, Puthiyottil et al (52) showed that in adult patients who remained alive after AKI, the urinary β2MG/creatinine ratio at 2 weeks was higher compared to control group, and it is predictive of low estimated glomerular filtration rate at 1 year. Furthermore, urine level β2MG in resuscitated patients after cardiac arrest at admission and day 3 were independently associated with high risk of AKI, mortality, and poor neurological outcome in a study published by Beitland et al (53).…”