ESPN 50th Annual Meeting

ESPN 2017


 
Does the pathogenesis of anemia differ in renal transplant recipients vs patients with chronic kidney disease?
CIGDEM ORUC 1 NUR CANPOLAT 1 ESRA PEHLIVAN 1 ÖZLEM BALCI EKMEKÇI 2 SALIM ÇALIŞKAN 1 LALE SEVER 1

1- DEPARTMENT OF PEDIATRIC NEPHROLOGY, ISTANBUL UNIVERSITY CERRAHPASA FACULTY OF MEDICINE, ISTANBUL, TURKEY
2- DEPARTMENT OF BIOCHEMISTRY, ISTANBUL UNIVERSITY CERRAHPASA FACULTY OF MEDICINE, ISTANBUL, TURKEY
 
Introduction:

Although similar factors play a role in both post-renal transplant anemia (PTA) and anemia in CKD patients, additional mechanisms regarding immunosuppressive medications, antimicrobial drugs, episodes of rejections and altered inflammatory milieu exist in pathogenesis of PTA. The present study aimed at elucidating risk factors of PTA and comparing anemia and inflammation related parameters in RTx and CKD patients. 

Material and methods:

Of the enrolled 68 participants in our single-centered, cross-sectional study, 48 were RTx, who were transplanted before 18 years of age. The other 20 participants were with CKD and comparable to RTx group in terms of age, gender and eGFR. Data on primary renal disease, mode and duration of dialysis, donor and transplant properties, list of medications and certain laboratory findings were collected from patient records. Serum levels of erythropoietin (EPO), hepcidin-25, and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assays. The ratio of EPO to Hgb was calculated to estimate endogenous EPO resistance. Maintenance immunosuppression consisted of standard triple therapy with prednisolone, CNI and purine antagonists in 42 patients. Nine patients were on antiviral treatment. Anemia was defined according to the World Health Organization thresholds

Results:

The prevalence of anemia was 46% in RTx group and 30% in CKD group (p=0.285). Renal transplant group had significantly lower median (IQR) of Hgb [12.1 (1.5) vs 13.1 (1.8) g/dl; p=0.04], higher serum EPO levels [7.66 (2.15) vs 6.46 (4.17) mIU/ml, p<0.001] and higher EPO/Hgb ratios [0.64 (0.19) vs 0.5 (0.37), p<0.001]. Neither hepcidin-25 nor IL-6 levels differed between the two groups. In the multivariate analysis, presence of anemia in RTx group was independently associated with lower levels of eGFR (p=0.001) and higher ratios of EPO/Hgb (p=0.014); whereas in CKD group it was independently associated only with lower levels of iron (p=0.007).

Conclusions:

Our findings show that relative EPO resistance plays a causative role in PTA as well as in impaired renal function. Although, the cause of EPO resistance could not be explained in the scope of our research, we postulate that for RTx recipients it might be attributable to immunosuppressive therapy.