Of the many theoretical causes of rheumatoid arthritis(RA), the most widely held theory is the autoimmune mechanism. In order to clarify the clinical significance of the immunological tests in RA, we studied immunoglobulin and complement levels in sera and synovial fluids of 118 RA patients and the following results were obtained. 1) The levels of immunoglobulins were elevated in both serum and synovial fluid and this was more prominent in the seropositive cases than the seronegative ones. 2) The levels of C3 component were decreased in both serum and synovial fluid, while those of C4 were decreased only in synovial fluid. Serum C3 and C4 component levels were more decreased in the seropositive cases than the seronegative ones. 3) The immunoglobulin levels in serum (IgG, IgM and IgA) and synovial fluid (IgG and IgA) and the levels of C3, C4 component in serum were well correlated with the clinical forms of rheumatoid arthritis. 4) The IgA level in serum and IgM level in synovial fluid were more increased in the exacerbated cases than the chronic ones. 5) Serum IgG level was decreased after steroid medication over one month.
Arthritis, Rheumatoid/blood/*immunology/metabolism ; Complement 3/analysis ; Complement 4/analysis ; Female ; Human ; Immunoglobulins/analysis ; Immunologic Tests ; Male

OBJECTIVETo evaluate the performance of BNII auto-analyzer system in detecting C3 and C4.

METHODSCLSI 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.

RESULTSThe 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.

CONCLUSIONThe performances of DADE BNII System basically meet the recognized standards in clinical detection of C3 and C4, but the method comparison needs further validation.

Autoanalysis ; methods ; Blood Chemical Analysis ; instrumentation ; methods ; Complement C3 ; analysis ; Complement C4 ; analysis ; Humans ; Nephelometry and Turbidimetry ; instrumentation ; methods ; Proteins ; analysis ; Sensitivity and Specificity

OBJECTIVE: To investigate the risk factors of different types of Henoch-Schönlein purpura (HSP) in Tibetan patients at high altitude, as to provide reference for correctly identifying high-risk patients. METHODS: A retrospective study was used to analyze the 304 HSP patients admitted to Tibet Autonomous Region People's Hospital from April 2014 to March 2022. The gender, age, allergic history, family history, clinical type, laboratory indexes (hemoglobin, platelet count, eosinophil, C-reactive protein (CRP), albumin, immunoglobulin G, immunoglobulin A, complement C3 and C4) were analyzed retrospectively. Univariate and multivariate Logistic regression analysis to screen for risk factors affecting different types of HSP. RESULTS: Renal HSP patients showed higher IgA [(9.2±1.7) g/L vs. (6.4±2.4) g/L, P=0.015], lower complement C3 [(203.3±21.6) mg/dL vs. (301.1±19.5) mg/dL, P=0.043], and complement C4 [(33.5±2.3) mg/dL vs. (53.0±7.2) mg/dL, P=0.032]. The patients with abdominal HSP showed lower levels of hemoglobin [(119.6±19.6) g/L vs. (146.6±47.3) g/L, P=0.038] and plasma albumin [24.8 (22.1, 33.9) g/L vs. 32.6 (24.6, 35.1) g/L, P=0.045]. The patients with articular HSP exhibited higher CRP [13.5 (0.2, 20.6) g/L vs. 7.5 (0.1, 15.2) g/L, P=0.036] and erythrocyte sedimentation rate (ESR) [24 (5, 40) mm/h vs. 15 (4, 30) mm/h, P=0.049]. Elevated IgA and decreased complement C4 were risk factors for renal HSP, anemia and decreased plasma albumin were risk factors for abdominal HSP, and elevated CRP was a risk factor for articular HSP. CONCLUSION The clinical characteristics of different types of HSP in plateau areas were different. Patients with high IgA, low complement C4, anemia, hypoalbuminemia, and significantly elevated CRP should be highly vigilant. Early and effective intervention can improve the clinical efficacy, avoid severe development, and improve the prognosis.
Humans ; Retrospective Studies ; Tibet/epidemiology* ; Complement C3/analysis* ; IgA Vasculitis/complications* ; Altitude ; Complement C4 ; C-Reactive Protein/analysis* ; Immunoglobulin A ; Risk Factors ; Anemia ; Hemoglobins/analysis* ; Serum Albumin/analysis*

OBJECTIVETo establish and optimize methods to detect the immune complexes (IC) of hepatitis B virus directly.

METHODSA C1q solid phase ELISA, mouse anti-HBs MAb solid phase ELISA and the complement consumption assay were established to detect the IC and these methods were optimized.

RESULTSAll the three methods were highly sensitive, specific and reproducible. The C1q used for coating tended to lose its activity easily at room temperature. Although strict requirements are needed for the raw and processed materials for complement consumption assay and the process of manipulation is complex, it can quantitatively detect IC. Comparing to the C1q solid ELISA and complement consumption assay, the mouse anti-HBs MAb solid phase ELISA has its own merits: convenience and stability.

CONCLUSIONMouse anti-HBs MAb solid phase ELISA is the best way to detect IC directly.

Complement C1q ; analysis ; Complement Fixation Tests ; methods ; Enzyme-Linked Immunosorbent Assay ; methods ; Hepatitis B ; blood ; Humans ; Reproducibility of Results

Hereditary angioneurotic laryngeal edema (HALE) is an autosomal dominant hereditary disease in which there is a decrease or defect in the C1 inhibitor (C1-INH). The pathophysiology of HALE is characterized by recurrent spontaneous episodes of transient edema of the laryngeal mucose and submucosal tissue with remission at irregular. Patients may die because of a life-threatening acute upper airway obstruction caused by laryngeal edema. HALE was diagnosed on the clinical symptoms, family history, and markedly decreased serum C1-INH activity and C1-INH protein.
Angioedemas, Hereditary ; diagnosis ; Complement C1 Inactivator Proteins ; analysis ; metabolism ; Complement C1 Inhibitor Protein ; Humans ; Laryngeal Edema ; diagnosis ; Recurrence

PURPOSE: Local activation of the complement system plays a role in target organ damage. The aim of our study was to investigate the influence of cyclosporine (CsA)- induced renal injury on the complement system in the kidney. MATERIALS AND METHODS: Mice fed a low salt (0.01%) diet were treated with vehicle (VH, olive oil, 1mL/kg/day) or CsA (30mg/kg/day) for one or four weeks. Induction of chronic CsA nephrotoxicity was evaluated with renal function and histomorphology. Activation of the complement system was assessed through analysis of the expression of C3, C4d, and membrane attack complex (MAC), and the regulatory proteins, CD46 and CD55. CsA treatment induced renal dysfunction and typical morphology (tubulointerstitial inflammation and fibrosis) at four weeks. RESULTS: CsA-induced renal injury was associated with increased the expression of C3, C4d, and MAC (C9 and upregulation of complement regulatory proteins (CD 46 and CD55). Immunohistochemistry revealed that the activated complement components were mainly confined to the injured tubulointerstitium. CONCLUSION: CsA-induced renal injury is associated with activation of the intrarenal complement system.
Animals ; Antigens, CD45/analysis ; Antigens, CD46/analysis ; Antigens, CD55/analysis ; Complement C3/analysis ; Complement C4b/analysis ; Complement Membrane Attack Complex/analysis ; Complement System Proteins/*analysis ; Cyclosporine/*toxicity ; Disease Models, Animal ; Immunity, Innate/drug effects ; Immunoblotting ; Immunohistochemistry ; Immunosuppressive Agents/toxicity ; Kidney/*drug effects/immunology/pathology ; Kidney Diseases/*chemically induced/immunology ; Mice ; Microscopy, Confocal ; Peptide Fragments/analysis

OBJECTIVETo study the diagnostic value of determinations of serum acute phase reaction protein, such as complement 3 (C3), complement 4 (C4), prealbumin (PA) and C-reactive protein (CRP), etc., in patients with severe acute respiratory syndrome (SARS).

METHODSSerum levels of C3, C4, PA and CRP were determined by turbidimetry in 54 cases of SARS, 20 of other pneumonia and 30 normal persons.

RESULTSSerum concentrations of C3, C4, CRP and PA were (1.18 +/- 0.42) g/L, (1.15 +/- 0.56) g/L, (10.52 +/- 8.77) mg/L and (107 +/- 54) mg/L in SARS patients, (1.30 +/- 0.46) g/L, (0.57 +/- 0.31) g/L, (0.88 +/- 0.43) mg/L and (291 +/- 76) mg/L in patients with other pneumonia, and (1.11 +/- 0.56) g/L, (0.38 +/- 0.26) g/L, (0.42 +/- 0.26) mg/L and (376 +/- 74) mg/L in normal persons, respectively. Serum level of PA was significantly lower and levels of C4 and CRP significantly in patients with SARS higher than those in patients with other pneumonia and normal persons (P < 0.01). There was no significant difference in serum level of C3 between the three groups (P > 0.05).

CONCLUSIONDetermination of serum level of C4, CRP and PA in suspected patients is beneficial to early differential diagnosis for SARS.

Acute-Phase Proteins ; analysis ; Acute-Phase Reaction ; blood ; Adult ; Aged ; C-Reactive Protein ; analysis ; Complement C3 ; analysis ; Complement C4 ; analysis ; Female ; Humans ; Male ; Middle Aged ; Prealbumin ; analysis ; Severe Acute Respiratory Syndrome ; blood

BACKGROUND AND OBJECTIVES: According to the correlation between hearing injury and McBride disability rating presented by previous studies, there are over/underestimated cases particularly in the 40 dB hearing range compared to other ranges. In this study, we reviewed the overestimated and underestimated data and propose a complementation scheme for a disability rating system by using the linear regression analysis. SUBJECTS AND METHOD: For the past 14 years, we have provided legal advisory for 121 cases of hearing injury, for which disability had to be rated. We reviewed all but excluded 11 cases for the aggravation of disability. A regression equation was produced from a linear regression analysis that used the percent of hearing handicap (AAO-HNS/AMA-1979 formula) as an independent variable (x) and McBride disability rating (%) as a dependent variable (y), following the Pearson correlation test. Iterative calculation was performed for overestimated (18) and underestimated (8) cases. RESULTS: Appropriate disability ratings were 14% for the cases overestimated to 20% and 11% for those underestimated to 5%. Appropriate disability ratings for the 20% of overestimated cases were changed to 14%, and for the 5% of the underestimated cases, the disability ratinb 11%. Iterative calculation showed that the Pearson correlation index was improved from 0.8866 to 0.9065 and the determination coefficient of regression analysis (adjusted R-square) was improved from 0.784 to 0.8202. CONCLUSION: The common range of hearing injury, which falls between 30-40 dB corresponds to the percentage of hearing handicap of 7.5-22.5%. A fairer assessment of ability rating would be possible by complementing some parts of this hearing range.
Complement System Proteins* ; Disability Evaluation ; Hearing Loss ; Hearing* ; Jurisprudence ; Linear Models* ; Regression Analysis*

OBJECTIVETo investigate the value of serum IgA/C3 ratio in the diagnosis of IgA nephropathy and explore its relationship with the clinicopathological features of the patients.

METHODSSixty-six patients with IgA nephropathy, 111 with other glomerular diseases, and 40 healthy control subjects without kidney disease were tested for serum IgA and C3 levels using CRM470 adjusted standardized immune turbidimetric method, and the IgA/C3 ratio was calculated. According to Oxford and Lee's classification criteria, we analyzed the pathological grades of the renal biopsy samples from patients with IgA nephropathy. The ROC curve was used to assess the value of serum IgA and IgA/C3 ratio in predicting IgA nephropathy.

RESULTSPatients with IgA nephropathy had an elevated serum IgA/C3 ratio than those with other glomerular diseases and the control subjects, with an area under the ROC curve of 0.776. An elevated serum IgA/C3 ratio was not found to significantly correlate with the pathological grade of renal biopsy samples in patients with IgA nephropathy.

CONCLUSIONIn the absence of renal biopsy findings, serum IgA/C3 ratio can help in the diagnosis of IgA nephropathy.

Biopsy ; Case-Control Studies ; Complement C3 ; analysis ; Glomerulonephritis, IGA ; blood ; diagnosis ; Humans ; Immunoglobulin A ; blood ; Kidney ; pathology

Measurements of serum C3 levels by the single radial immunodiffusion method using Helena plates were done in 41 patients with acute poststreptococcal glomerulonephritis and in 25 healthy children. In 28 patients the sequential determination were done until returning the level above normal range. The mean value of serum C3 concentration in this group as a who1e was lower than in the control group and the difference was statistically significant (p < 0.001). The initial reduction of serum C3 concentration did not correlate with the severity of the acute phase of the disease. In those children with acute poststreptococcal glomerulonephritis, serum C3 concentration returned to normal within six weeks.
Adolescent ; Child ; Child, Preschool ; Complement 3/analysis* ; Complement 3/deficiency ; Female ; Glomerulonephritis/etiology ; Glomerulonephritis/immunology* ; Human ; Male ; Streptococcal Infections/complications ; Streptococcal Infections/immunology*