Levitt's CO Breath Test To Measure RBC Lifespan In The Applied Research Of Diagnosis And Treatment Of Renal Anemia

Anemia is a common complication of chronic kidney disease(CKD),almost appearing in the whole stage of chronic kidney disease,and is particularly prevalent in end-stage chronic kidney disease.The mechanism of renal anemia is extremely complex,mainly including erythropoietin inadequacy,shortening of red blood cell(RBC)lifespan,urine toxin suppression of bone marrow hematopoietic disorder,lack of hemoglobin nutrients,such as folic acid,ferritin,vitamin B12,and so on.Lacking of erythropoietin production is widely considered to be the primary cause of renal anemia.Previous research on red blood cell lifespan almost concentrated in the end-stage chronic kidney disease,with the early stage overlooked.CO breath test is a convenient,reliable and accurate method to detect red blood cells lifespan.Now we have a simple method to carry out large number of clinical studies.The RBC lifespan of Patients with end-stage chronic kidney disease(CKD)is shorter than healthy people,which has been repeatedly verified.What about the early stage CKD patient's RBC life span? Meanwhile,maintenance hemodialysis is the main treatment for patients with chronic end-stage renal disease.Previous studies have shown that hemodialysis increases damage of red blood cells.Is it still the fact as the dialysis technological advancement? To explore the above two problems,this study will be divided into two parts.The first part,we used Levitt 's carbon monoxide breath test to detect different stage of CKD patients' RBC lifespan of patients,combined with erythropoietin,reticulocyte absolute value,vitamin B12,ferritin,folic acid,six index of the pathogenesis of anemia,to assess the effect of shorten RBC lifespan on chronic renal anemia.70 CKD patients never undergoing dialysis and smoking were enrolled.According to the National Kidney Foundation specified guidelines,The patients were divided into five groups based on glomerular filtration rate.Each participant's RBC lifespan,the concentration of erythropoietin,reticulocyte absolute value,vitamin B12,ferritin,folic acid was detected.Analysising the linear correlation between hemoglobin concentration to the result of RBC lifespan and erythropoietin respectively.Using independent students t test to test the difference of the result of CKD stage1~ 5 RBC lifespan and erythropoietin.Using Mann-Whitney test to test the differences of reticulocyte percentage content of protein,vitamin B12,ferritin,folic acid between groups.There was significant difference between the two groups if P<0.05.The results of mean RBC lifespan to CKD stage 1 ~ 5 were 128±56 days?111±27 days?90±32 days?88±28 days and 60±24 days.There was no difference between CKD stage 1 and 2(P > 0.05).The RBC lifespan of CKD stage 3and stage 4 was30 days shorter than CKD stage 1(P < 0.05).CKD stage 5 RBC lifespan significantly shorter than the CKD stage 4(P < 0.05),it's indicating that RBC lifespan in CKD stage 3 began to have a shortened lifespan compared with healthy people.The results of mean concentration of erythropoietin to CKD stage 1 ~ 5 were 8.4±3.9 iu/L ?6.4±2.9 iu/L? 11.1±5.7 iu/L?10.6±4.5 iu/L?7.2±4.7 iu/L.The concentration of EPO in CKD stage 3 and stage 4 were higher than stage 1 and 2.The concentration of EPO in CKD stage 3 and stage 4 had significant difference compared with CKD stage 2(P < 0.05).The result of reticulocyte absolute value in CKD Stage 1 showed no difference compared with CKD stage 3 and stage 4(P > 0.05),except CKD stage 5,which is lower than CKD stage 1(P < 0.05).The result of folic acid,iron,vitamin B12 in CKD stage 1 to stage 5 were no statistical difference(P > 0.05).The results indicated that CKD stage 5 RBC lifespan consistent with traditional viewpoint,which is lower than normal.However,The RBC lifespan in CKD stage 3 began to shorter than healthy people,this has never been reported in the past.On the contrary,the concentration of erythropoietin in CKD stage 3 was higher than that of CKD stage 2.We could conclude that the effect of shorten RBC lifespan on CKD anemia appear to earlier than other index,especially early in the effect of the lack of erythropoietin in CKD.The second part of this study aimed to use a carbon monoxide(CO)breath test to investigate the effects of hemodialysis on the red blood cell life span in patients with chronic end-stage renal disease.17 non-smoking men with chronic end-stage renal disease had hemodialysis performed.The dialysis membrane was made of polysulfone,which is different from other studies that used a cellulose acetate membrane.Levitt's CO breath test was performed to compare changes in the red blood cell life span before and after dialysis.None of the 17 patients showed significant fluctuations in endogenous CO concentrations.The mean red blood cell life span was 66.0±31.0 days before dialysis and 72.0±26.0 days after dialysis,with no significant difference between the two points(p>0.05).Dialysis using a polysulfone membrane has no significant effects on the red blood cell life span in patients with chronic end-stage renal disease,and does not aggravate damage to red blood cells.The reduced red blood cells lifespan after dialysis from previous report may vary according to different filtration materials.