A comparative analysis of four methods for eliminating M protein interference in serum uric acid detection
Objective To compare the differences among dilution method,polyethylene glycol(PEG)precipitation method,ultrafil-tration membrane filtration method,and manual calculation method in eliminating M protein interference in uric acid detection and eval-uate their clinical application value.Methods The serum samples affected by M protein interference were subjected to uric acid detec-tion and calculation using dilution method(deionized water and physiological saline),PEG precipitation method,ultrafiltration mem-brane filtration method,and manual calculation method.The values of obtained from the four methods were compared,and the result of ultrafiltration membrane filtration method was used as the reference value.Results The relative biases between the results of the dilu-tion method and the ultrafiltration method after different dilutions of deionized water and physiological saline were as follows:-32.38%and-60.66%at 3-fold dilution,-26.23%and-46.72%at 5-fold dilution,and-22.13%and-30.33%at 10-fold dilution.The rela-tive bias between the PEG precipitation method and the ultrafiltration method was-3.28%.The bias before and after PEG precipitation in 10 control samples ranged from-3.80%to 2.34%.The relative bias between the results of the ultrafiltration membrane filtration method and the patient's original results was 687.10%.The biases of the manual calculation method compared to PEG precipitation method and the ultrafiltration membrane filtration method were-1.64%and 1.69%,respectively.The biases of 10 control samples were between-4.62%and 0%.Conclusion The four methods for clearing M protein interference in uric acid detection have their own ad-vantages and disadvantages in terms of accuracy,convenience,cost-effectiveness,and practicality.PEG precipitation method and ultra-filtration membrane filtration method have the highest accuracy,but they were more cumbersome to operate and have higher consumable costs.The dilution method was easy to perform and has good practicality and cost-effectiveness,but its accuracy was poor.The manual calculation method requires good understanding of uric acid detection parameters and instrument detection principles.Its calculation re-sults were close to those of the ultrafiltration membrane filtration method,making it convenient,economical,and rapid,and it could be used as routine clinical method.