Changes in glomerular filtration rate and mortality in multıple myelome patients with chronic kidney disease

Aim: At the time of diagnosis, renal dysfunction present and it aimed to evaluate the effect of changes in glomerular filtration rate on mortality in multiple myeloma patients with chronic kidney disease and to evaluate factors affecting mortality. Material and methods: Sixty four multiple myelom patients who had renal dysfunction at the diagnosis and renal disfunction lasted more than 3 months in the Nephrology Department of the Internal Medicine Department of Inonu University Medical Faculty were included into the study. We collected baseline characteristics and laboratory results such as age, gender, resume, hemoglobin, hematocrit, leukocyte, thrombocyte, blood urine nitrogen (BUN), creatinine, uric acid, total protein, albumin, calsiyum, phosphorus, C- reactive protein, urine microprotein creatinine ratio, Ig G, Ig M, Ig A and sedimentation retrospectively from the computerized patient record system. Average values are taken as the average of all measurements made at three-month intervals. Clinical practice guidelines for K/DOQI indicate that GFR decreases by 1 ml/min/year after reaching a peak level of 125 ml/min in adulthood (30-40 years) in normal individuals. For each patient, the eGFR decline rate (slope) (mL/min-1/1.73 m2 -1/year-1) was determined by linear regression analysis using all calculated eGFR values over the study period. The K/DOQI clinical practice guidelines suggest that, in normal individuals, GFR decreases by 1 ml/min/year after a peak level of 125 ml/min has been reached in adulthood (30–40 years). Therefore, any reduction greater than this is considered to be a progressive slope (slope more negative than -1 ml/ min/year (-1), stable (>-1 to <+1), or an improved slope if it shows more of an increase, i.e., greater than +1.0 ml/min/year). Findings: Of 64 patients, 17 (26.6%) had a progressive slope, 10 (15.6%) stable slope, 37 (57.8%) improved slope. Mean eGFR slope was 3.4 ± 12.2 ml/min/year. eGFR level was significantly higher at the time of diagnosis in the group with progressive slope compared to the other groups. However, in this group, the eGFR value slope calculated according to the mean values of all measurements during follow-up was not different with improved slope group. There was no difference between these three groups in terms of life span and mortality. In multivariate Cox regression analysis, not having autologous stem cell transplantation was found to be a prognostic factor for mortality (Hazard ratio: 2.478 95.0% Cl 1.067-5.753, p=0.035). Patient age, primary treatment, relapse of the disease, level of eGFR at diagnosis, mean of eGFR at follow-up and eGFR slope were not shown relationship with mortality. As a result, multiple myeloma patients with chronic kidney disease may benefit from autologous stem cell transplantation to have a longer life span. Keywords: Chronic kidney disease, Factors affecting eGFR, Multiple myeloma