BACKGROUND: In vitro levels of complement C3 and C4 proteins are sensitive to storage conditions. To avoid in vitro complement activation when testing is delayed, serum should be frozen at -20degrees C within 2 hr of venipuncture. However, this is impractical in routine laboratory work. Therefore, we investigated alterations in C3 and C4 levels in refrigerated specimens over time and derived formulae to estimate initial levels of complement concentrations in delayed testing. METHODS: Ten fresh specimens were measured for C3 and C4 concentrations and were refrigerated at 4degrees C. We measured C3 and C4 levels in refrigerated samples daily for 4 days using an automated nephelometer (Beckman Coulter Inc., USA). RESULTS: C3 and C4 levels were significantly increased over time in refrigerated specimens (P<0.001, P<0.001, respectively). The increments in C3 and C4 levels were described by the equations: C3 (mg/dL)=3.55x+87.18 (r=0.9909), and C4 (mg/dL)=0.72x+22.3 (r=0.9395), where x=the number of days samples were refrigerated before testing. Increases in C3 and C4 concentrations were described on a percentage basis by the equations: DeltaC3 (%)=4.14x+1.07 (r=0.9903), and DeltaC4 (%)=3.57x+2.48 (r=0.9405). CONCLUSIONS: As the measured C3 and C4 concentrations increased by 3.55 mg/dL (4.1%) and 0.72 mg/dL (3.6%) per day in refrigerated specimens, the levels of C3 and C4 should be adjusted in delayed testing. We proposed that the formulae presented be used to back-calculate initial levels of C3 and C4 concentrations.
Complement Activation ; Complement C3* ; Complement C4 ; Complement System Proteins ; Phlebotomy

OBJECTIVE: To investigate the significance of detecting serum complement C3 and C4 in patients with multiple myeloma (MM) and to explore its correlation with myeloma bone disease (MBD). METHODS: The levels of serum complement C3 and C4 in 69 MM patients and 30 healthy people were examined by scatter nephelometry. The bone density of L1-4 vertebral body, bilateral femoral neck and bilateral hip joints were measured by dual energy bone density meter (DXA). RESULTS: The levels of serum complement C3 and C4 in MM patients significantly increased in comparison with that in healthy people (P＜0.01). The patients in advanced clinical stage exhibited a higher levels of C3 and C4 than those in stable stage (P＜0.01). In addition, the patients with grade C of MBD had a higher levels of serum complement C3 and C4 than those in patients with grade A and B of MBD (P＜0.01). The levels of serum complement C3 and C4 in MM patients negatively correlated with bone density in L1-4 vertebral body, bilateral femoral necks and hip joints. The correlation coefficients were r=-0.938, r=-0.659, r=-0.745, r=-0.748, r=-0.596 in complement C3 and r=-0.908, r=-0.623, r=-0.710, r=-0.714, r=-0.595 in complement C4, respectively. CONCLUSION The levels of complement C3 and C4 positively correlate with the severity of bone disease and bone density in MM patients, which suggests that complement C3 and C4 plays important roles in the development of MBD. The levels of serum C3 and C4 may be the sensitive biomarkers of MBD.
Biomarkers ; Complement C3 ; metabolism ; Complement C4 ; metabolism ; Femur Neck ; Humans ; Multiple Myeloma

OBJECTIVE: To study the expression and diagnostic value of plasma miR-145 and miR-183 in children with lupus nephritis (LN). METHODS: A total of 92 children with LN who were admitted from January 2016 to May 2019 were enrolled as the LN group, among whom 17 had type II LN, 15 had type III LN, 36 had type IV LN, 18 had type V LN, and 6 had type VI LN. Forty healthy children who underwent physical examination were enrolled as the healthy control group. According to Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), the 92 children with LN were further divided into a stable LN group with 34 children (SLEDAI score <10) and an active LN group with 58 children (SLEDAI score ≥10). RT-PCR was used to measure the expression of miR-145 and miR-183 in plasma. The receiver operating characteristic (ROC) curve was used to analyze the value of plasma miR-145, miR-183, and anti-dsDNA antibody in the diagnosis of LN. Pearson correlation analysis was used to investigate the correlation of the expression levels of miR-145 and miR-183 in plasma with laboratory markers. RESULTS: The LN, active LN, and stable LN groups had significantly higher levels of anti-dsDNA antibody, C-reactive protein, serum creatinine (Scr), and blood urea nitrogen (BUN) than the control group (P<0.05). The active LN group had significantly higher SLEDAI score, anti-dsDNA antibody, Scr, and BUN than the stable LN group (P<0.05). The LN, active LN, and stable LN groups had significantly lower levels of complement C3, complement C4, and serum albumin (Alb) than the control group (P<0.05). The active LN group had a significantly lower level of Alb than the stable LN group (P<0.05). The LN, active LN, and stable LN groups had significantly lower plasma levels of miR-145 and miR-183 than the control group (P<0.01). The active LN group had significantly lower plasma levels of miR-145 and miR-183 than the stable LN group (P<0.01). The children with difference types of LN had significantly lower plasma levels of miR-145 and miR-183 than the control group (P<0.01), and the type V-VI group and the type IV group had significantly lower plasma levels of miR-145 and miR-183 than the type II-III group (P<0.01). The ROC curve analysis showed that the optimal cut-off values of plasma miR-145, miR-183, and anti-dsDNA antibody were 1.05, 0.62, and 186.30 IU/mL respectively, in the diagnosis of LN, and the combination of these three indices had the largest area under the ROC curve of 0.896 (95%CI: 0.835-0.955), with a sensitivity of 90.5% and a specificity of 84.2%. In the children with LN, the plasma levels of miR-145 and miR-183 were negatively correlated with SLEDAI score, anti-dsDNA antibody, Scr, and BUN (P<0.05) and were positively correlated with complement C3, complement C4, and Alb (P<0.05). CONCLUSIONS There are significant reductions in the expression levels of miR-145 and miR-183 in plasma in children with LN, which are correlated with the activity level and pathological typing of LN. Combined measurement of miR-145, miR-183, and anti-dsDNA antibody has a high value in the diagnosis of LN.
Biomarkers ; Child ; Complement C4 ; Humans ; Lupus Nephritis ; genetics ; MicroRNAs ; genetics ; ROC Curve

The authors evaluated the stress response to cardiopulmonary bypass by measuring plasma Ig G, A, M and C3, C4concentrations. Anesthesia was induced with fentanyl, and all patients were underwent open heart surgery using bubble type heart-lung machine. Blood samples were obtained pre-induction, sternotomy, 10 min. and 30 min. after cardiopulmonary bypass, and 10 min. after termina tion of cardiopulmonary bypass and after transport to L.C.U. IgG, A, M and complement C3, C4concentrations were measured by Turbidmeter using Behring Turbidquant. The results were as follows: 1) Plasma concentrations of IgG, A, M and C3, C4 at preinduction period were 1345. 00+/-194. 42, 289. 10+/-100.4, 177.43+/-72.65, 59.20+/-16.33, 20.50+/-7.54 mg/dl., respectively. 2) Ten min. after cardiopulmonary bypass, the plasma concentration was significantly decreased when compared with the baseline values (p<0.01). 3) Thirty min. after cardiopulmonary bypass, the plasma concentration of the complenent C3, C4 were significantly decreascd (p<0.01). 4) In the 1ntensive care unit, Ig and complement C3, C4 were increased, but did not reach control values. Considering the above results, we conclude that the decrease of plasma Ig G, A, M and complenent C3, C4concentrations are related to mechanical stress of the cardiopulmonary bypass, and to certain activators such as denaturated protein, heterogenous RBCs, and foreign materials, etc.
Anesthesia* ; Cardiopulmonary Bypass* ; Complement C3* ; Complement C4 ; Complement System Proteins* ; Fentanyl* ; Heart-Lung Machine ; Humans ; Immunoglobulin G* ; Immunoglobulins* ; Plasma ; Sternotomy ; Stress, Mechanical ; Thoracic Surgery

OBJECTIVE: Infiltrating T cells and monocytes have been implicated in the pathogenesis of lupus nephritis (LN). Chemokines may play a key role in the recruitment of these cells. We investigated whether RANTES (regulated on activation normal T cell expressed and secreted), one of the CC chemokine family, may be involved in the pathogenesis of LN. METHODS: We measured the levels of RANTES in sera and urine from 87 systemic lupus erythematosus (SLE) patients and 78 healthy controls using ELISA. Clinical and laboratory assessment including SLE disease activity index (SLEDAI) were performed at the time of sampling. RESULTS: Serum RANTES levels were significantly higher in the patients with SLE than in healthy controls (115.0+/-5.6 vs. 91.5+/-4.0 pg/ml, p=0.001, mean+/-SEM). Serum RANTES levels correlated well with anti-dsDNA antibody titer (r=0.29, p<0.05) and inversely with serum complement C4 level (r=-0.28, p<0.05). Urinary RANTES/creatinine ratios were significantly higher in patients with nephritis than those without (3.4+/-0.4 vs. 2.2+/-0.3, p=0.004), while serum RANTES level was not different between patients with nephritis and those without. Moreover, urinary RANTES/creatinine ratio positively correlated with urine protein/creatinine ratio (r=0.41, p<0.001). CONCLUSIONS: Our results demonstrate that serum RANTES was elevated in patients with SLE and urinary excretion of RANTES was strongly associated with presence of nephritis. These data suggest that RANTES may be expressed in renal inflammatory sites and may participate in the pathogenesis of LN possibly by augmenting the recruitment of T cells and monocytes.
Chemokine CCL5* ; Chemokines ; Complement C4 ; Enzyme-Linked Immunosorbent Assay ; Humans ; Lupus Erythematosus, Systemic ; Lupus Nephritis* ; Monocytes ; Nephritis ; T-Lymphocytes

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

OBJECTIVETo investigate the level of mRNA expression of complement C3 and C4 in rat nasal mucosa and to reveal the relationship with the pathogenesis of allergic rhinitis (AR) .

METHODSTwenty healthy SD rats were randomly divided into AR group and control group, 10 rats for each group. Ten rats was sensitized and intranasally challenged by ovalbumin and Al (OH)3 (as supplement) as allergic rhinitis models, and the control group was treated by saline. RT-PCR was performed to investigate the level of mRNA expression of complement C3 and C4 in nasal mucosa of both groups.

RESULTSC3 and C4 mRNA were detected in both groups. The relative intensity of gene expression was measured. The relative intensity of C3 mRNA expression was 6183+/-1376 in AR group, 4444+/-989 in control group, C4 mRNA was 4398 +/-948 in AR group, and 2771+/-407 in control group. Expression of C3 and C4 in AR group was higher than that of the controls ( P < 0. 05) .

CONCLUSIONThe high level of C3 and C4 mRNA expression in nasal mucosa of rats with allergic rhinitis suggests that C3 and C4 are involved in the immunopathology of allergic rhinitis. The result implies that complement system involved in the rat's allergic rhinitis is possibly activated through the classical pathway.

Animals ; Complement C3 ; metabolism ; Complement C4 ; metabolism ; Female ; Male ; Nasal Mucosa ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Rhinitis, Allergic, Perennial ; metabolism

OBJECTIVETo investigate the impact of intravenous nutrition on plasma free amino acid spectrum and immune function for patients with sepsis.

METHODSForty severe sepsis patients were divided into two groups: Group B (amino acids + glucose + fat emulsion) and Group A (glucose + fat emulsion), 20 healthy individuals were enrolled as control group. The concentration of free amino acid and immune globulin were determined after 3 days.

RESULTSIn Group A, the levels of valine, leucine, isoleucine, alanine, serine, glutamic acid, histidine, proline and glycine were decreased; while the levels of threonine, cysteine, the ratio of phenylalanine and tyrosine (Phe/Tyr) were higher than those in control group. Meanwhile, peripheral blood IgM, complement C3 and C4 were decreased. In group B, all amino acid levels were improved, but the level of alanine, serine, glutamic acid, histidine and proline still lower than those in control group. Similarly, the levels of IgM, complement C3 and C4 in group B were increased.

CONCLUSIONIntravenous nutrition can support the basal requirement of amino acid and improve the immune function of patients with sepsis.

Adult ; Aged ; Amino Acids ; blood ; Complement C3 ; metabolism ; Complement C4 ; metabolism ; Female ; Humans ; Immunoglobulin M ; blood ; Male ; Middle Aged ; Parenteral Nutrition, Total ; Sepsis ; blood ; immunology ; therapy ; Time Factors

OBJECTIVETo investigate the effects of rhubarb powder on serum complement 3 (C3), complement 4 (C4), and hypersensitive C-reactive protein (hs-CRP) levels in patients with hypertensive intracerebral hemorrhage (HICH) after operation.

METHODSForty inpatients with HICH after operation were recruited from Department of Cerebral Surgery, Affiliated Hospital of Shaanxi College of Traditional Chinese Medicine from July 2009 to March 2010. They were randomly assigned to the treatment group (20 cases) and the control group (20 cases). From the 4th day after surgery, all patients received routine Western medical treatment. The rhubarb powder, 5-10 g dissolving in 40 mL warm water, was administered or nasally fed to those in the treatment group, 2 -3 times daily for 10 successive days. The contents of serum C3, C4, and hs-CRP were detected in the two groups on the 7th day and the 14th day after operation. The serum hs-CRP content was detected using latex particle enhanced immunoturbidimetric assay. The Scandinavia Stroke Scale (SSS) scores were recorded in the two groups.

RESULTSCompared with the same group on the 4th day after operation, the levels of serum C3 and C4 increased on the 7th day after operation, and SSS score increased on the 14th day after operation in the control group (P < 0.05). The contents of C4 and hs-CRP decreased, and the SSS score increased on the 14th day after operation in the treatment group (P < 0.05). Compared with the same group on the 7th day after operation, the contents of C4 and hs-CRP decreased and the SSS score increased on the 14th day after operation in the treatment group (P < 0.05). Compared with the control group at the same time points, the contents of C4 and C3 decreased on the 7th day after operation; the contents of C3, C4, and hs-CRP decreased, and SSS score increased in the treatment group on the 14th day after operation (P < 0.05).

CONCLUSIONThe rhubarb powder could significantly decrease the serum levels of C3, C4, and hs-CRP, and improve the curative effect in patients with HICH after operation.

Adult ; C-Reactive Protein ; metabolism ; Cerebral Hemorrhage ; blood ; Complement C3 ; metabolism ; Complement C4 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Female ; Humans ; Male ; Middle Aged ; Postoperative Period ; Rheum ; chemistry

OBJECTIVE: To study the clinical value of lymphocyte subsets, immunoglobulins, and complement C3 and C4 in the evaluation of immune status in children with hand-foot-mouth disease (HFMD). METHODS: A total of 282 children with HFMD were enrolled as the HFMD group, and 130 healthy children were enrolled as the healthy control group. The percentages of peripheral CD3, CD4, and CD8 T lymphocytes, CD19 B lymphocytes, and CD56 natural killer cells were measured. The CD4/CD8 ratio was calculated. The levels of immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G (IgG), and complement C3 and C4 were measured. RESULTS: The multivariate analysis showed that compared with the healthy control group, the HFMD group had significantly lower percentages of CD3, CD4, and CD8 T lymphocytes and levels of complement C3 and C4 (P<0.05), as well as significantly higher percentage of CD56 natural killer cells and level of IgG (P<0.05). The individual effect analysis showed that the children aged 0-3 years in the HFMD group had a significantly higher CD4/CD8 ratio than the healthy control group (P<0.05); boys aged 0-3 and ≥3 years in the HFMD group had a significantly higher level of IgM than the healthy control group (P<0.05); boys aged ≥3 years and girls aged 0-3 years in the HFMD group had a significantly lower level of IgA than the healthy control group (P<0.05). CONCLUSIONS Cellular and humoral immunity disorders are observed in children with HFMD. The monitoring of lymphocyte subsets and immunoglobulin levels can provide a laboratory basis for immune status assessment in children with HFMD.
Child, Preschool ; Complement C3 ; Complement C4 ; Female ; Hand, Foot and Mouth Disease ; Humans ; Immunoglobulins ; Infant ; Infant, Newborn ; Killer Cells, Natural ; Lymphocyte Count ; Lymphocyte Subsets ; Male