ABSTRACT
Objective To investigate the clinical and electrophysiological characteristics of anti-myelin-associated glycoprotein (MAG)-associated peripheral neuropathy, as well as its antibody detection methods, treatment and prognosis. Methods Six cases of IgM paraproteinemia and anti-MAG antibody-associated peripheral neuropathy were summarized. All of the patients came from Peking Union Medical College Hospital and Qilu Hospital since April 2014 to February 2018. The clinical features, electrophysiological characteristics, and auxiliary examinations including anti-MAG antibody results were analyzed, and the treatment and prognosis were followed. Results Of the six patients, five were male and one was female. The age of onset was 50-77 years and the duration was three months to six years. All the six cases suffered from numbness of distal limbs and gradually progressed to the proximal limbs, of which three cases had muscle weakness. Walking instability occurred in five cases. One patient had electricity-like pain in the lower extremities. Reflexes in the four limbs decreased in five cases, and gloves and socks-like deep sensation decreased in six cases. Five patients underwent lumbar puncture and the cerebral spinal fluid protein ranged from 0.75 to 1.33 g/L. Serum monoclonal proteins were found in six patients, of which four were IgM kappa and two were IgG kappa and IgM kappa biclonal. Four cases were diagnosed with monoclonal gammopathy of undetermined significance and two cases were diagnosed with Waldenstr?m's macroglobulinaemia. Abnormal electromyography was detected in all the six cases, suggesting demyelinating peripheral nerve damage with secondary axonal damage, which was sensory predominant and more severe in lower limbs than upper limbs. In all the six cases, anti-MAG-IgM antibodies were all positive by indirect immunofluorescence assay based on transfected cells and peripheral nerve tissues. After the diagnosis, three patients underwent RCD (rituxima + dexamethasone + cyclophosphamide) chemotherapy. One patient improved (the modified Rankin scale (mRS) score was 3 before treatment and 2 three years after treatment), one patient was stable, and one patient was still in follow-up. One patient was treated with rituxima, and the condition improved (the mRS score was 3 before treatment and 1 one year after treatment). Conclusions MAG-associated peripheral neuropathy can present a slow progressed distal symmetric sensomotor peripheral neuropathy with predominant sensory symptoms. Electromyography shows demyelinating change. Monoclonal protein is usually IgM kappa. MAG-IgM antibodies detection by indirect immunofluorescence assay based on transfected cells and peripheral nerve tissues can support the diagnosis. RCD chemotherapy may be effective.
ABSTRACT
Objective To explore achieving the consistent method of blood lipid examination by comparing the results of 5 dif-ferent blood lipid detection system commonly used in the use of refernce method to assign freach blood serum before and af-ter calibration.Methods Used the indoor quality control total variation (CV%)to evaluate the 5 blood lipid examination system of the imprecision.Referenced the United States Clinical and Laboratory Standardization Institution (CLSI)9A2 EP program,compared with 54 fresh blood serum in 5 commonly used examination system of Total Cholesterol (TC)and Tri-glyceride (TG),and then estimated the bias between the different detection systems and mean value.8 of the samples were determined by the reference method and estimate the bias of different system.The fresh frozen serum samples assigned by reference method were used to evaluate the above examination system,then compare and estimate the bias again with the same 54 fresh serum samples.Compared the variation of 54 samples in different detection system before and after calibra-tion.Results The TG imprecision of 5 examination system were between 3.76%~23.65%,the TC imprecision between 2.19%~23.43%,that mean the results were good,the r value of TG were between 0.996 7~0.999 6 and the TC were 0.956 2~0.996 7.But there were obvious differences between the results of the systems,and the biggest difference were 14.72%~34.21% in TG and 3.11%~14.57% in TC.After use the serum assignment by reference method,the variation of the systems has been significantly decreased.Conclusion Using the reference method to assign the fresh serum of different blood lipid detection system can effectively improve the consistency of the results.
ABSTRACT
Objective To validate the four chronic kidney disease epidemiology collaboration (CKD-EPI) predictive equations based on serum creatinine (SCr) and cystatin C (Cys C) in Chinese CKD patients,and try to develop the GFR predictive equations for Chinese CKD patients.Methods254 CKD patients were randomly selected from four Grade ⅢA hospitals in different regions in China from September 2007 to December 2010.Clearance of dual plasma sampling 99mTc-DTPA was used to measure glomerular filtration rate (rGFR) in 254 CKD patients.The serum concentration of Cr and Cys C were measured.CKD-EPI SCr equation,Cys C equation,Cys C equation adjusted for age,sex and race,SCr/Cys C combinated equation adjusted for age,sex and race were used to estimate GRF ( labeled as eGFR1,eGFR2,eGFR3 and eGFR4,respectively).The correlation,bias and precision of eGFRs were compared with rGFR by Wilcoxon signed rank test,intraclass correlation coefficient (ICC) and Spearman correlation analysis.The deviation degree between rGFR and different eGFRs was compared via Bland-Altman graph.The accuracy within 15％,25％,30％ ( P15,P25,P30) and the staging correctness of eGFR against CKD at different stages was calculated.ResultsThe rGFR in 254 CKD participants was [ 48.07 (26.19 -92.97 )] ml · min -1·(1.73 m2) -1.The Spearman correlatiou coefficients (CC) of eGFR and rGFR varied within the range of 0.873 - 0.896 ( P =0.000 ).The intra-class CC ( ICC ) varied within the range of 0.920 - 0.942.The correlation of eGFR4 was the best.The absolute deviations of 4 eGFRs and deviation precision were eGFR4 ＜eGFR3 ＜ eGFR2 ＜ eGFR1.The 95％ confidence intervals for the regression line of 4 eGFRs shown by Bland-Altman graphs were 92.5,87.3,83.0 and 76.1 ml · min-1 · ( 1.73 m2 ) -1,respectively,with the best result of eGFR4.For P30,the correctness of 4 eGFRs were eGFR4 ＞ eGFR3 ＞ eGFR2 ＞ eGFR1,but no significant difference was found by Chi square test (x2 =6.448,P =0.092).The overall correctness rate in 4 eGFRs against CKD stages were 48.4％ -57.5％,with the highest consistency of eGFR4,but their staging correctnessratewerenotideal(Kappa values were 0.405,0.348,0.366 and 0.463,respectively).Conclusions Compared with CKD-EPI SCr equation,no advantage was found in CKD-EPI Cys C equation.The Cys C equation adjusted by age and sex shows a little advantages over CKD-EPI Cys C equation in bias,precision,correlation and accuracy.The CKD-EPI SCr/Cys C combinated equation adjusted by age,sex and race has advantage over other three equations not only in bias,precision,correlation and accuracy,but also in staging correctness.However,the validation of this equation is still not fairly ideal for Chinese CKD patients.Based on these findings,it is essential for the Chinese CKD patients to develop SCr/Cys C combined predictive equation which adjusted by age,sex or other factors.(Chin J Lab Med,2012,35:798-804)