Clinical Correlates and Reference Intervals for Cystatin C in a Han Population from Southeast China.

BACKGROUND: Cystatin C (CysC) is an endogenous filtration marker for estimation of kidney function. This study aimed to define the reference interval (RI) for serum CysC in a southeast Chinese adult population and to explore the variables that affect serum CysC levels. METHODS: 532 reference individuals (259 male, 273 female, aged 18 - 79 years) were recruited from Guangzhou, China. Multiple regression analysis (MRA) was used to investigate the association between serum CysC levels and clinical factors including age, gender, body mass index, lifestyle, and biochemistry parameters. Reference values were defined using a parametric method according to Clinical and Laboratory Standards Institute guideline (C28A3). RESULTS: The mean serum CysC levels were significantly lower in females than in males (p < 0.001). Serum CysC levels increased with age (~0.047 mg/L increase per decade). MRA demonstrated that serum CysC levels correlated significantly with serum creatinine (Cr), high density lipoprotein (HDL-C), alkaline phosphatase (ALP), albumin (ALB), and uric acid (UA) concentrations, although their relationships were less prominent than those of gender or age. The RIs for serum CysC levels were calculated at 0.73 - 1.17 mg/L for subjects aged 18 - 49 years and at 0.73 - 1.49 mg/L for those aged 50 - 79 years. CONCLUSIONS: The RIs for serum CysC were established in a southeast Chinese population. In addition to gender and age, serum Cr, HDL-C, ALP, ALB, and UA also influenced serum CysC levels.

Performance evaluation of the Sysmex Cystatin C assay on the Roche Modular P Analyzer.

OBJECTIVES: Serum Cystatin C (CysC) is a promising endogenous marker for estimation of glomerular filtration rate. This study evaluated the analytical performance of the Sysmex CysC assay on the Roche Modular P Chemistry Analyzer (Modular P). DESIGN AND METHODS: The evaluation of imprecision, linearity, recovery, and interference were performed in accordance with the relevant Clinical and Laboratory Standards Institute guidelines protocols, using quality controls and patient samples. Comparison studies were conducted against the Siemens and Roche assay for CysC. RESULTS: At CysC concentrations of 0.45 and 1.80mg/L, the within-run coefficient of variations (CVs) were 2.81% and 2.04%, respectively, and the between-run CVs were 3.14% and 3.26%. The CysC assay was proven throughout the measuring range from 0.10 to 8.00mg/L. Good correlations were achieved among the 3 CysC assays. The Sysmex assay appeared to report higher results than the Siemens assay. No interference was detected from hemoglobin 5g/L, bilirubin (free or conjugated) 200mg/L, or chyle 1500 formazin turbidity units. CONCLUSIONS: The Sysmex CysC assay performed well with regard to basic performance, including precision, dilution linearity, and effects of interfering substances, and is an acceptable assay for the determination of CysC on the Modular P.

[Triptolide inhibites Th17 cell differentiation via regulating cyclooxygenase-2/ prostaglandin E2 axis in synovial fibroblasts from rheumatoid arthritis].

Triptolide (TPT), an active compound extracted from Chinese herb Tripterygium wilfordii , has been used in therapy of rheumatoid arthritis (RA). In this study, after synovial fibroblasts from rheumatoid arthritis (RASFs) were treated with TPT, we investigated its effect on the differentiation of Th17 cells. Firstly, the mRNA level of cyclooxygenase (COX) wad detected by qRT-PCR and the protein level of prostaglandin E2 (PGE2) was tested by ELISA in RASFs treated with different concentrations (0, 10, 50, 100 nmol L-1 ) of TPT. Then after TPT pre-treated RASFs and RA CD4 + T cells wer e co-cultured for 3 days in the presence or absence of PGE2, IL-17 and IFN-gamma production in CD4 T cell subsets were detected by flow cytometry. The results showed TPT decreased the mRNA experssion of COX2 and the secretion of PGE2 in RASFs in a dose-dependent manner(P <0. 05). We further found that differentiation of Thl7 cells was downregulated in a dose-dependent manner, and exogenous PGE2 could reverse the inhibition of Th17 cell differentiation(P <0. 05). Taken together, our results demonstrated that TPT inhibited the mRNA level of COX2 and the secretion of PGE2 in RASFs, which partly led to impaired Th17 cell differentiation in vitro.

[Expression of recombinant extracellular region of human interleukin-1 receptor type I in Pichia pastoris].

OBJECTIVE: To construct pPICZalphaA-soluble interleukin-1 receptor type I (sIL-1RI) recombinant expression vector containing the gene fragment encoding the extracellular domain of sIL-1RI for its expression in Pichia pastoris. METHODS: sIL-1RI gene was amplified by RT-PCR and inserted into the yeast expression vector pPICZalphaA by digestion ligation. The recombinant plasmid pPICZalphaA-sIL1RI was transformed into E.coli Stb13, and the positive clones were analyzed by PCR and DNA sequencing. The pPICZalphaA-sIL1RI recombinant plasmid was electroporated into GS115 cells and the transformants were analyzed by PCR. After phenotype identification, the recombinant strains were induced by methanol to express the target protein, which was analyzed by Western blotting of the cell extract and supernatant. RESULTS: The recombinant plasmid pPICZalphaA-sIL-1RI was constructed successfully, and the results of Western blotting showed that yeast induced by methanol expressed a protein of about 39 kD. CONCLUSION: sIL-1RI protein has been successfully expressed in P.pastoris expression system, which provides the basis for further study of sIL-1RI.

[Determination of IgM-RF, IgA-RF, IgG-RF, IL-1RI, CDK2 and ROC evaluation in patients with rheumatoid arthritis].

OBJECTIVE: To assess the value of rheumatoid factors IgM-RF, IgA-RF, IgG-RF, interleukin-1 receptor type I (IL-1RI) and cyclin-dependent kinase 2 (CDK2) in the diagnosis of rheumatoid arthritis (RA). METHODS: IgM-RF, IgA-RF, IgG-RF, IL-1RI and CDK2 were detected in 47 patients with active RA, 47 with inactive RA, 20 with active systemic lupus erythematosus (SLE), 20 with inactive SLE, 20 with acute upper respiratory tract infection (AURTI), and 20 healthy controls using enzyme-linked immunosorbent assay (IgM-RF, IgA-RF, IgG-RF, IL-1RI) and time-resolved fluoroimmunoassay (CDK2). RESULTS: Patients with active and inactive RA showed significant differences in peripheral serum CDK2 and IgA-RF levels (P<0.05). Between active and inactive RA patients, RA patients and SLE patients, RA patients and AURTI patients, and RA patients and the control subjects, the area under curve (AUC) of the receiver operating characteristic curve (ROC) was 0.561, 0.814, 0.799, and 0.888 for IgM-RF, 0.596, 0.678, 0.729, and 0.850 for IgA-RF, 0.614, 0.718, 0.692, and 0.791 for IgG-RF, 0.646, 0.691, 0.762, and 0.835 for IL-1RI, 0.803, 0.753, 0.741, and 0.840 for CDK2, respectively. CONCLUSIONS: IgM-RF may have high value in the diagnosis and differential diagnosis of RA, and CDK2 can be useful for differential diagnosis between active and inactive RA.

[Assessment of the performance of an automated analysis system in detecting C3 and C4].

OBJECTIVE: To evaluate the performance of BNII auto-analyzer system in detecting C3 and C4. METHODS: CLSI protocols (EP15-A, EP6-A, EP9-A2) and other relevant literatures were use to or evaluate the precision, accuracy, linearity of C3 and C4 detection by the auto-analyzer system, and the results were compared with the recognized standards. RESULTS: The relative bias of C3 and C4 was less than one third of the CLIA'88 standard and the precision met the clinical requirement. The results tested by DADE BNII system were not compatible with those by Roche Modular System. C3 showed good linearity in the tests (R2>0.975, P<0.05) with a linearity range of 0.18-5.1 g/L. The linearity of C4 was not available because of lack of high-level samples. CONCLUSION: The performances of DADE BNII System basically meet the recognized standards in clinical detection of C3 and C4, but the method comparison needs further validation.

[Isolation and characterization of human rheumatoid arthritis fibroblast-like synoviocytes].

OBJECTIVE: To isolate and characterize human rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs). METHODS: The synovial membrane tissues were obtained from 4 RA patients, 1 chondroma patient and 1 healthy subject and FLS were isolated by means of tissue culture. The cell morphology was observed by phase-contrast microscope and the cell surface markers were detected by flow cytometry. RESULTS: The FLSs were successfully cultured from the synovial membrane tissues with good cell homogeneity after the third passage. The FLSs of the 3rd to 7th passages were stable and proliferated actively, followed by slow proliferation and aging since the 8th passage. Flow cytometry showed that the 4th-passage FLSs from the RA patients contained 99.04% CD90(+) cells, 2.73% CD3(+) cells, 0.29% CD3(-)CD19(+) cells, 2.81% CD3(-)CD16(+)CD56(+) cells, 5.89% CD14(+) cells, and 54.17% CD55(+) cells. The presence of interleukin-1 receptor type I (IL-1RI, 158.63-/+20.32 pg/ml) and IL-1beta (4.67-/+0.82 pg/ml) were detected in the cell culture supernatant of the 4th-passage FLSs from the RA patients by enzyme-linked immunosorbent assay ELISA. CONCLUSION: FLSs from RA patients can be effectively culture by means of tissue culture, and the cultured FLSs show high expressions of CD90, IL-1RI and IL-1beta.

[Association of interleukin-6 and interleukin-18 gene polymorphism with rheumatoid arthritis in Guangdong Han population].

OBJECTIVE: To investigate the single-nucleotide polymorphisms (SNPs) at positions -572 and -174 in the promoter region of interleukin-6 (IL-6) gene and at -607 and -137 in the promoter region of interleukin-18 (IL-18) gene for their association with rheumatoid arthritis (RA) in the Chinese Han population in Guangdong Province. METHODS: SNPs of IL-6 and IL-18 genes were detected in 120 patients with RA and 168 normal subjects using polymerase chain reaction with sequence-specific primers (PCR-SSP). RESULTS: SNPs at -572 and -174 of IL-6 gene and at -607 and -137 of IL-18 gene were detected in this population. There was a significant difference in the genotype and allele frequency at -572 and -174 of IL-6 gene and -607 of IL-18 gene (P<0.001), but not in the distribution of genotype frequencies at -137 of IL-18 gene between the RA patients and healthy subjects (P=0.141). A significant difference was found, however, in the allele frequency at -137 of IL-18 (P=0.024). Logistic regression analysis revealed significant association of age, gender, IL-6 gene -572, -174 and IL-18 gene -137 SNPs with RA (P<0.05). CONCLUSIONS: The polymorphisms of the promoter region of IL-6 gene at positions -572 and -174 is probably associated with RA, and further study is needed to understand the relation of the polymorphisms of IL-18 gene at positions -607C/A and-137G/C with RA.

[Dynamic observation IgG and IgM antibodies in patients with severe acute respiratory syndrome].

OBJECTIVE: To observe IgG and IgM antibodies in patients with severe acute respiratory syndrome (SARS) and to explore their significance. METHODS: IgG and IgM antibodies were detected in SARS Patients in the first, recovery and follow-up stages, the front healthy doctors and nurses and healthy volunteers with indirect enzyme-linked immunoadsorbent assay. RESULTS: The positive ratio of IgG was higher than that of IgM in SARS patients during the first stage. During the recovery, follow-up stages and in the front healthy crowd, the positive ratios of IgG were all higher than those of IgM. CONCLUSION: The changeable tendency SARS antibody is more different than that of other infectious diseases. This tendency can be used as a indicator for epidemiological study and serum diagnose.

[Relationship between acid-base disturbance in blood gas analysis and prognosis of patients with severe acute respiratory syndrome].

OBJECTIVE: To study the influence of the acute blood gas analysis index change on the prognosis of patients with severe acute respiratory syndrome (SARS). METHODS: Artery blood gas analysis indexes were determined in 38 of 103 cases of SARS patients during acute stage, the relationship between the change of blood gas analysis index and prognosis of patients with SARS was analyzed. RESULTS: The lower partical pressure of carbon dioxide in artery (PaCO2), partical pressure of oxygen in artery (PaO2) in blood was, the higher death rate was. pH in blood had no significant influence on the prognosis of SARS patients. The prognosis of SARS patients were worse and the death rate was higher when patient had two or more acid-base disturbance. CONCLUSION: The artery blood gas analysis is useful for judging the conditions and prognosis of patients with SARS, and is beneficial for clinical treatment.