Exploring Predictors Of Renal Reversibility In Multiple Myeloma

Background: Multiple myeloma(MM)is the second most common malignancy of the hematologic system,in which malignant proliferation of plasma cells causes end-organ or tissue damage,with the main clinical manifestations being anemia,renal impairment,bone destruction,and hypercalcemia.Renal impairment(RI)is one of the most serious comorbidities,with approximately 40% of MM patients presenting with RI at the time of diagnosis,and patients with RI usually have a worse prognosis and lower survival rate than those without RI.It has been shown that for newly diagnosed MM patients,the renal response achieved after treatment is positively correlated with survival.The reversibility of renal damage is a favorable prognostic factor for MM patients,so it is important to understand the reversibility of renal damage before patients start treatment.A study from Japan showed that the combination of EPO and urinary albumin excretion rate could more accurately predict the reversibility of renal response,and another study in China showed that chemotherapy regimen,treatment response,and high blood calcium were strong predictors of renal damage reversibility.There is no uniformity in the predictors of reversibility of renal damage,and further research is needed.Objective: The aim of this study was to investigate the predictors of renal reversibility in patients with NDMM with RI.Methods:We retrospectively analyzed the medical records of 79 NDMM patients with RI who were admitted to our hospital from August 1,2010 to July 31,2022 and completed four courses of chemotherapy.RI was defined as glomerular filtration rate<50m L/min/1.73m2 at initial diagnosis.According to the criteria of the International Myeloma Working Group,the renal response was defined by the criteria of CRrenal,PRrenal,MRrenal and NO response,and major renal response was defined as achieving CRrenal or PRrenal.based on the optimal renal response of patients after treatment,the study population was divided into achieving major renal response group and not achieving major renal response group,and univariate screening and multifactor analysis were performed to derive independent impact indicators,and the cutoff value was calculated by ROC curve.Each index was recorded as 1 point,and patients were grouped according to the cumulative score,and the diagnostic value of the index was verified by comparing the rate of achieving major renal response between different groups.Results: Of 79 patients with NDMM with RI,a total of 45(57%)achieved a major renal response after treatment,and 34(43%)did not.In a subgroup analysis of 37 patients with cystatin-C and urinary series protein indicators,20(54.1%)achieved a major renal response and 17(45.9%)did not.Univariate analysis yielded differences in bleeding urea nitrogen,serum creatinine,estimated glomerular filtration rate,serum albumin,serum globulin,albumin/globulin ratio(A/G),serum calcium,N-acetyl-β-D glucosidase(NAG),urinary β2-microglobulin,and urinary transferrin between the responding and nonresponding groups,and the differences were statistically significant.Multifactorial analysis yielded NAG and A/G as independent influencing factors for achieving major renal response.The cutoff value of NAG was 44 U/L and the cutoff value of A/G was 1.25.NAG>44 U/L and A/G<1.25 were counted as 1 point each,and37 patients were grouped according to the cumulative scores,and the major renal response was different among the groups,and the difference was statistically significant,and the higher the score,the higher the rate of achieving major renal response.The higher the score,the higher the rate of major renal response.Conclusion: NAG>44 U/L and A/G<1.25 were independent predictors of achieving a major renal response.