Objective:To evaluate the current status of alpha-fetoprotein (AFP) detection, a comparability analysis was conducted on the results measured by eight automated immunoassay systems, incorporating external quality assessment (EQA) data from the Beijing Center for Clinical Laboratories (BCCL) for the years 2020, 2021, and 2023.Methods:Methodological evaluation. Abbott Architect i2000, Beckman DxI 800, Roche Cobas E601, Diasorin Liaison XL, Maccura IS1200, Autolumo A2000, Leadman CI1000, and Mindray CL-2000i were used to detect 40 individual AFP serum samples that were collected from the laboratory of Beijing Chaoyang Hospital in 2019. The AFP results from eight different systems were compared with the median cohort. Passing-Bablok regression was used to evaluate the correlation between methods, and the concordance correlation coefficient was used to analyse the consistency between methods. Taking the optimal biological variability (±5.90%) as the criterion for bias evaluation, the bias between systems was evaluated using Bland-Altman analysis. The EQA results for AFP from BCCL over the past three years were statistically analysed to calculate the robust mean, robust coefficient of variation ( CV), and standard uncertainty within groups. The acceptance limit is based on the requirement of desirable biological variability (±21.87%) of allowable total error, and the pass rates were calculated for instrument or method groups, respectively. Results:The CVs of the eight detection systems were all≤1/3 allowable total error (±8.3%), passing the precision verification. The average relative biases between two detection systems (Roche Cobas E601 and Maccura IS1200) and the median cohort were>±5.90%, while the other six detection systems were<±5.90%. The eight detection systems showed good correlation and consistency with the median cohort (both R2 and concordance correlation coefficients>0.95). The results of EQA showed that there were no statistically significant differences in the robust means within each instrument or method group ( P>0.05). In the instrument group, except for Siemens and two other groups, the robust CVs of other groups were within 9%. The pass rates of most instruments and methods after being grouped were higher than the total pass rate, but that of the enzyme immunoassay chemiluminescence method was relatively low. Conclusions:The eight automated AFP immunoassay systems show a good correlation with the median cohort, and the consistency of AFP detection results is satisfactory among most detection systems. However, the comparability of AFP detection results for certain systems needs further improvement.

Objective:To investigate the regional homogeneity (ReHo) among the major depressive disorder patients without mixed features (MDD noMF), major depressive disorder with mixed features (MMF), bipolar disorder with mixed features (BMF) and bipolar disorder patients without mixed features (BD noMF) patients, and to explore the brain activity and functional connectivity patterns of the MMF and BMF patients. Methods:This was a cross-sectional study. The MDD noMF patients (MDD noMF group), MMF patients (MMF group), BMF patients (BMF group), BD noMF patients (BD noMF group), and age-and gender-matched healthy controls (HC group) were recruited from Beijing Anding Hospital, Capital Medical University between April, 2021 and June, 2022. All the participants underwent resting-state functional MRI scanning. The ReHo values was computed with the DPABI software based on the MATLAB. Firstly, the difference in ReHo among the patients with MDD noMF, MMF, BMF, BD noMF and HC group were estimated by the analysis of covariance and the post-hoc method (LSD or Games-Howell). And then, the brain regions with significant different ReHo values were selected as the seeds to calculate the functional connectivity with the whole brain. Results:A total of 29 cases in the MDD noMF group, 24 cases in the MMF group, 26 cases in the BMF group, 29 cases in the BD noMF group, and 42 in the HC group were included. The differences in ReHo values in the left fusiform and the left precuneus of the 5 groups were statistically significant ( P<0.05). Among of them, the ReHo values of the left fusiform were lower in the MMF, BMF and BD noMF groups compared with the HC group ( P<0.05), while the ReHo values of the left precuneus in MDD noMF, MMF, BMF and BD noMF groups were higher than that in the HC group ( P<0.05). The ReHo value of the left fusiform was lower in the MMF group compared with the MDD noMF group ( P=0.001); the ReHo value of the left fusiform was lower in the BMF group compared with the MDD noMF and BD noMF groups ( P<0.05). The functional connectivity between the left fusiform and vermis, left insula, right putamen, and left medial superior frontal gyrus, and functional connectivity between the left precuneus and right superior frontal gyrus (dorsolateral) showed significant difference among the MDD noMF, MMF, BMF, BD noMF and HC groups ( P<0.05). Compared with HC group, MDD noMF, MMF, BD noMF groups showed higher functional connectivity between the left fusiform and the vermis, and MDD noMF, MMF, BMF, BD noMF group showed higher functional connectivityy between the the left fusiform and the left insula, left medial superior frontal gyrus and right putamen ( P<0.05). Compared with the MDD noMF group, the MMF, BMF and BD noMF groups showed higher functional connectivity between the left fusiform and the left insula ( P<0.05). Compared with the MDD noMF group, the BMF and BD noMF groups had higher functional connectivity between the left fusiform and the left medial superior frontal gyrus ( P<0.05). The BMF group showed higher functional connectivity of the left fusiform with the right putamen than the MDD noMF and BD noMF groups. Additonally, the BMF and BD noMF groups showed higher functional connectivity between the left precuneus and the right superior frontal gyrus (dorsolateral) than HC, MDD noMF and MMF groups ( P<0.05). Conclusions:MMF and BMF patients have local abnormalities of functional activity synchronization in the left fusiform and precuneus and abnormal functional connectivity patterns with multiple brain regions. MMF and BMF patients have specific neuroimaging features compared to MDD noMF or BD noMF patients and also share similar neuroimaging pathogenesis.

Objective:To compare results of four glycosylated hemoglobin A1c (HbA1c) detection methods and to evaluate the uncertainty of HbA1C results in clinical laboratory, and to provide method for clinical laboratory on the evaluation of uncertainty.Methods:According to the four uncertainty evaluation methods, which were recommended by "CNAS-TRL-001, the evaluation and expression of measurement uncertainty in medical laboratory", the relative and absolute uncertainty of low, medium and high HbA1c in 33 clinical laboratories measured in 2019 and 35 clinical laboratories measured in 2020 was evaluated by more than 6 months of internal quality control (IQC) data, trueness verification and external quality assessment (EQA) data. The four uncertainty evaluation methods were: IQC data and trueness verification data (method 1), only trueness verification data (method 2), IQC and EQA data (method 3) and only EQA data (method 4). The related statistical methods used in this analysis were Friedman and Wilcoxon signed rank test.Results:For method 1, the median range of relative and absolute uncertainty of low, medium and high HbA1c detection in 2019 and 2020 ranged from 4.21% to 9.24% and from 0.27% to 0.64%, respectively. Compared to method 1, the relative and absolute uncertainties obtained by method 2 were smaller, and the differences were statistically significant ( P<0.016 7, P<0.05). Compared to method 1, the relative uncertainties obtained by method 3 and method 4 were smaller, except for the high concentration of HbA1c level in 2020. Among the 6 pairs of comparisons (low, medium and high HbA1c in 2019 and 2020), there were 3 pairs (high HbA1c in 2019, low and medium HbA1c in 2020) and 2 pairs (low and high HbA1c in 2020) of differences with statistical significance (all P<0.016 7). Conclusion:The uncertainty evaluation of HbA1c detection in clinical laboratory should be evaluated based on IQC and trueness verification data.

Objective:To establish a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) method for the direct detection of serum M protein without antibody enrichment, and to assess its detection performance.Methods:Method establishment. A total of 712 waste serum samples were collected from patients who applied for the M protein identification test in Beijing Chaoyang Hospital affiliated to Capital Medical University. The immunoglobulin light chain was obtained by reduction of IgG and IgA by TCEP, and the detection method was preliminarily determined. The waste serum samples from 20 healthy people were collected to determine the range of mass-to-charge ratios of κ and λ light chain ions. 8 parallel tubes and 8 batches were set up for intra-and inter-batch reproducibility evaluation. 10-fold, 100-fold and 200-fold diluted M protein from 23 positive samples were detected by established MALDI-TOF MS method, and its sensitivity was evaluated. 3 methods of IFE, SPE and MALDI-TOF MS were used to detect M protein simultaneously, and the coincidence rate between MALDI-TOF MS and IFE and SPE was calculated.Results:The repeatability within and between batches was 100%, respectively. The original, 10-, 100-and 200-fold dilutions of 23 M protein-positive samples were determined, and the detection limit of MALDI-TOF MS for M protein was 0.06-0.18 g/L. IFE as the gold standard, the overall coincidence rates of SPE and MALDI-TOF MS were 85.9% and 92.3%, respectively, and the positive coincidence rates of SPE and MALDI-TOF MS were 72.8% and 99.7%, respectively, of the 712 samples. Among the different types of M-proteins, MALDI-TOF-MS agreed 100% with IFE M-protein results for IgA, IgD, IgM, free light chain type and biclonal group, while the agreements of SPE for IgM, IgA and free light chain samples were only 66.7%, 58% and 19.5%, respectively. One positive sample in the IgG group was not detected by MALDI-TOF MS. 23 M-proteins positive samples were diluted by original, 10, 100 and 200 times to access the sensitivity of MALDI-TOF MS method. The coincidence rate of MALDI-TOF MS was 100% and IFE was 96% at 10-fold dilution. The coincidence rate of IFE was 28% and 23% of MALDI-TOF MS at 100-fold and 200-fold dilution, respectively.Conclusions:A MALDI-TOF MS method for the detection of serum M-proteins was successfully established. This method has the advantages of high detection throughput, fast speed, good sensitivity, specificity and coincidence rate.

Objective:To establish the sex-, age-and season-specific (month) reference intervals (RI) for thyroid stimulating hormone (TSH) measurement by big data and indirect method in adults.Methods:TSH data of anonymous patients were collected from Beijing Chaoyang Hospital Affiliated to Capital Medical University in 2016, the data were selected and outliers were removed. Indirect methods (Hoffmann method and Bhattacharya method) were used to calculate TSH reference intervals of whole population, different genders, ages and seasons (months). TSH RI from two indirect methods of total population, selected population, physical examination population was compared with RI from reagent instruction according to reference change value ( RCV) based on biological variability. Results:A total of 61 599 records were obtained from 90 699 records including 18 776 males and 42 823 females. The TSH RI were obtained by Hoffmann method: the whole population, 0.59-5.59 μIU/ml (1 μIU/ml=1 mIU/L), male, 0.53-5.16 μIU/ml, female, 0.59-6.11 μIU/ml. The upper limits of TSH RI were higher with age and in winter (January): 18-30 years old, 0.62-5.57 μIU/ml, 71-80 years old, 0.49-6.45 μIU/ml; January, 0.59-6.40 μIU/ml, August, 0.60-5.56 μIU/ml; The RI of TSH by Bhattacharya method: the whole population, 0.58-5.80 μIU/ml, male, 0.55-5.02 μIU/ml, female, 0.62-6.21 μIU/ml. The upper limits of TSH RI were also higher with age and in winter (January): 18-30 years old, 0.65-5.67 μIU/ml, 71-80 years old, 0.46-5.99 μIU/ml, January: 0.61-6.52 μIU/ml, August: 0.61-5.69 μIU/ml. Compared to RI from reagent instruction, the differences of TSH RI from two indirect methods of total population, selected population, physical examination population were acceptable.Conclusions:TSH RI was established by indirect method. With the increase of age and winter, the upper limit of TSH reference interval tends to increase.

Objective To explore the CRP harmonization by calibration using commutable trueness verification materials. Methods High and low level of CRP concentrations trueness verification materials(H and L) were prepared by Beijing center for clinical laboratories. Thesetrueness verification materials were diluted to 5 calibration points(5L, 4L+1H, 3L+2H, 1L+4H, 5H) by weighing method, respectively. These 5 points were used to calibrate four different brands of CRP detection system (Diasys, Leadman, Siemens and Roche) instead of the original procedure. Sera from 21 patients and the international standard ERM DA-474/IFCC were used to compare harmonization and trueness after calibration. Each sample above was measured twice. Results After calibration, the median of CV was reduced from 19.33％ to 2.92％ among 21 patient samples, less than the optimal CV based on biological variability (CV=10.6％). Compared with Desai, the slopes were closer to 1 from 0.90-1.09 to 0.93-0.96 after calibration. Meanwhile, if ERM-DA474/IFCC was used as the trueness verification materials, the absolute bias wasreduced from 3.08-11.07 mg/L to 0.52-2.97 mg/L which was close to theuncertainty of itself (2.5 mg/L). Conclusions Afterthe calibration which contained five linear concentration points of CRP trueness verification materials by weighing method, both harmonization and trueness of CRP were improved.

Objective To prepare the trueness verification materials of C-reactive protein (CRP) and evaluate its homogeneity, stability and commutability. Methods The high and low CRP concentrations trueness verification materials were from patient leftover sera which were pooled, mixed thoroughly, filtered and aliquoted. The homogeneity, stability and commutability of these materials were evaluated according to CNAS(China National Accreditation Service for Conformity Assessment, CNAS)-GL29:2010 "Reference materials-General and statistical principles for certification (ISO Guide35:2006)"and the Clinical and Laboratory Standards Institute (CLSI) EP30A. The trueness verification materials were used to evaluate the commutability in 10 clinical CRP detection systems, using forty-five patients' leftover sera with different CRP concentration evaluated by Deming regression in EP30A of CLSI. Meanwhile, the commutability of dilution series of ERM DA-474/IFCC were evaluated using the same method. Results A total of two CRP concentration level trueness verification materials were prepared, with high and low concentration levels of 754 and 743 vials, 1 ml each, respectively. The preparation showed good homogeneity (F

Objective To value C-reactive protein ( CRP ) trueness verification materials and to perform the CRP trueness verification program in Beijing .Methods The CRP value of trueness verification materials were assigned by the international reference material ERM DA-474/IFCC, using 10 clinical routine detection systems at departments of clinical laboratory of Beijing Chaoyang and Luhe Hospital Affiliated to Capital Medical University .The calibration curves with 4 ERM DA-474/IFCC dilutions were established and used for value transfer for trueness verification materials of two levels .The uncertainty was also assessed during the process.Then, the trueness verification was performed in the EQA at Beijing Center for Clinical Laboratories ( BCCL ) among 42 clinical laboratories.The samples were distributed according to BCCL standard operating procedure .The Microsoft Excel 2007 and SPSS 17.0 were used to process the results and the function of efficiency ( En) was calculated to verify the difference between the value and the overall mean of all participating laboratories .Results The values and uncertainties of two trueness verification materials of CRP were (109.9 ±9.4) mg/L and (27.1 ±2.4) mg/L respectively.The results of trial application of two level trueness verification materials in the EQA at Beijing Center for Clinical Laboratories (BCCL) were satisfied.There were no significant difference between the transfer values from our study and the values from means of all laboratories in Beijing .The function of efficiency ( En ) was less than 1.Conclusions The valueswhich were established by using multiple detection platforms for CRP trueness verification materialswere accurate and the uncertainties were small .This method is a preferably method for CRP value assignment because there was no suitable reference method for CRP measurement till now .Thematerialswere suitable for the trueness verification program for clinical laboratories in Beijing .

Objective To prepare the frozen human serum pools for AFP reference materials through quantity value transmission from several analysis systems . Methods Method establishment. According to the requirement of preparation for the national standard materials , the studies of homogeneity and stability of frozen human serum pools for AFP reference materials were carried out .The commutability of prepared AFP reference materials and WHO AFP 72/225 reference material were assessed .By use of four automated chemiluminescence analysis systems , the prepared reference materials and different dilutions of WHO reference material 72/225 were tested in the same run.The values of prepared AFP reference materials were assigned by comparing these results and the uncertainty was evaluated .Results The three levels of AFP reference materials were tested to be homogeneous .The long term stability had been observed at -80℃for 14 months.The different dilutions of WHO AFP 72/225 reference material and three levels of prepared reference materials were commutable with patient serum samples among the four analysis systems .Through multiple system quantity value transmission and total uncertainty evaluation , the assigned values ( IU/ml) of three levels of AFP reference materials were 23.0 ±3.0, 93.2 ±7.2, ( 26.1 ±2.4 ) ×102 respectively.Conclusions The three levels of AFP reference materials were homogeneous and stable in accordance with requirement of preparation for national standard materials .The assigned values were reliable.The materials showed accepted commutability across 4 analytical systems.These materials had been approved as the national certified reference materials .These reference materials could be applied for the calibration or calibration verification of clinical analytical systems and the external quality assessment schemes for clinical laboratories.

Objective To investigate the internal quality control ( IQC ) on clinical chemistry , clinical immunology and clinical hematology in mutual recognition laboratories in medical institutions in Beijing.Methods By means of questionnaire survey and on -site investigation, fresh frozen serum and whole blood samples with assigned values by reference method were measured to investigate the status of IQC on clinical chemistry , clinical immunology and clinical hematology in 142 mutual recognition laboratories in medical institutions of Beijing,and results were analyzed.Results 142 copies of questionnaireson clinical chemistry, clinical immunology and clinical hematology were send out and 120, 97, and 101 laboratories returned the questionnaires respectively .The information feedback rate was 84.5%, 68.3% and 71.1%respectively .All the questionnaires were effective .Questionnaires survey results showed that more than 50%laboratories set up quality control goals and the most of the goals were probability for error detection ( Ped) 95%, probability for false rejection(Pfr)5%;About 70% laboratories usecd the same quality control plan for different tests ;The most frequently used quality control rules are 12s/13s/22s.On-site investigation showed that ,take the results of clinical chemistry for example , based on the desirable biological variation and WS/T 403 -2012 , most of the tests can't meet the quality control goalsunder the existing quality controlcondition.Conclusion Clinical laboratories should consider their actual situations , assess their own qualitylevels that they can reach , set reasonable quality standards for themselves , and make appropriateindividualized quality control plan.