Reciprocal changes in serum levels of immunoglobulins (IgG, IgA, IgM) and complements (C3, C4) in normal pregnancy and after delivery.

Sequential changes in serum levels of IgG, IgA, and IgM, and C3 and C4 during and after pregnancy were studied in 8 healthy women. Serum IgG decreased gradually during pregnancy, but increased markedly during the six months following delivery. Serum IgA and IgM levels also showed patterns similar to IgG. In contrast, C3 and C4 levels increased significantly and reached maximum levels in the last trimester during pregnancy, but decreased gradually for six months after delivery. Reciprocal changes between immunoglobulins and complements were clarified for the first time, and were suggestive of a compensatory autoregulatory mechanism in the suppression of the humoral immune system during pregnancy.     

Reference intervals for serum IgG, IgA, IgM, C3, and C4 as determined by rate nephelometry

We report reference intervals for IgG, IgA, IgM, C3, and C4 for a population of 750 well children and 120 healthy adults. Ranges were established by rate nephelometry (previous studies have been based on immunodiffusion). Our results generally agree with previously established immunoglobulin ranges, except for some disagreement as to ages when adult values are attained.     

Serum IgG, IgM and IgA concentration determined by the "linear plate" immunodiffusion technique in a normal population

Using the “linear plate” immunodiffusion technique, the authors have determined the serum IgG, IgM and IgA levels in normal populations. The incidence of storage of the samples at ?20° for a prolonged time was investigated and also the influence of age on immunoglobulin levels in a normal population. The reference sera were obtained by mixing a great number of serum samples (four pools were obtained for each immuniglobulin) containing the protein at markedly different levels. The immunoglobulin concentration of each pool was determined by comparison with a calibration curve obtained with well weighted quantities of immunochemical pure human IgG or IgM or IgA powder. The frequency distribution of the immunoglobulin levels in the populations investigated was found to be of the log normal type. The mean levels (1275 mg/100 ml for IgG; 74 mg/100 ml for IgM and 208 mg/100 ml for IgA) fit very well with the data reported by most authors using other methods. The determination of the IgG level was not influenced by storage of the samples at ?20°. A decrease of IgM and IgA was, however, observed when sera were kept frozen for a period of 3 months.No significant variation was found between the IgG and IgM levels of the different age classes. For the IgA's, however, the authors found a slight but significant increase between 20 and 30 years. Between the older age classes the increase is slower and between 40 and 60 there is no longer a significant change.     

Albumin, IgG and IgA in normal adult human pancreatic juice

Normal human pancreatic juice was collected by catheterisation of the main pancreatic duct in 5 adult subjects of two sexes. On these samples containing proteolytic enzymes in the zymogen form, we found and quantitated albumin, IgG and IgA by the single radial immunodiffusion technique. Albumin represents 1.26 ± 0.36% (at p< 0.05) of total proteins of pancreatic juice; IgG 0.23 ± 0.039 and IgA 0.18 ± 0.034. The albumin/IgG ratio is not significantly different from that in human serum while the albumin/IgA and IgG/IgA ratios significantly differ. This fact favours the hypothesis of a local synthesis of IgA and/or a specific excretory mechanism, however this latter seems less likely.     

Basic characteristics and evaluation of a partially automated Behring laser nephelometer for the measurement of IgG, IgA, IgM and C3c in serum

We have evaluated a partially automated Behring laser nephelometer for the measurement of IgG, IgA, IgM and C3c in serum. The system consisted of a manual Behring laser nephelometer, an automatic cuvette carrier and a Hewlett-Packard 9815 A calculator/printer. The system could process 240 preincubated samples per h when the interval between each voltage reading was set at 15 s. Day-to-day precision was near 6%. We obtained the worst precision for the determination of IgG which requires the smallest volume of diluted sample (10 microliters). The Frigen treatment used to clarify turbid sera seems to decrease IgG and increase C3c concentrations. The addition of polyethylene glycol 6000 at a concentrations of 40 micro/L in the reaction mixture did not improve the assay ranges. Comparison studies with radial immunodiffusion for the four proteins and with the IgM - BMC Immunological Turbidity Test using either least-squares or Deming's regressions gave very good correlation figures, except for C3c and for some IgM paraproteins. We could decrease the cost per test by re-using the plastic cuvettes. The utilization of the calculator-printer greatly simplified data handling but the automatic carrier was not considered a real asset without complete automation.     

The specific detection of IgG, IgA and the complement components C3 and C4 in circulating immune complexes

Four immune complex assays (PEG assays) are described; they are based on the binding of radio-labelled immunospecific antibodies to immune complexes containing IgG, IgA, C3 or C4, and subsequent precipitation with polyethylene glycol. Comparison of the results of the IgA-PEG assay with those of an existing immune complex assay (alpha-IgA-InhBA) showed that the former detects only large-sized (greater than 25 S) material. This was also demonstrated by sucrose density gradient ultracentrifugation of immune complexes in patients' sera as well as in preparations of aggregates containing IgA, C3 or C4. By using aggregates of mixed composition (IgG, IgA, C3 and C4) it was shown that each constituent could be detected by one of the 4 assays. Immune complexes containing the various constituents could also be detected in sera of patients with a variety of disorders. Further studies are needed to establish whether these constituents occur within the same complex or within different complexes.     

Intra-individual variation in creatinine and cystatin C.

BACKGROUND: Serum creatinine and cystatin C are measured in the assessment of glomerular filtration rate. Biological variation of an analyte is an important determinant of its usefulness. Intra-individual variation in serum creatinine and cystatin C in healthy subjects was determined in this study. METHODS: Weekly blood samples were taken from 10 healthy subjects and analysed for creatinine (kinetic Jaffe method) and for cystatin C (by nephelometry). RESULTS: Intra-individual variations for serum creatinine and cystatin C were 6.1% and 4.55%, respectively. Index of individuality values were similar for the analytes (0.35 for both). CONCLUSION: Intra-individual variations for serum creatinine and cystatin C were similar in healthy subjects.     

乙肝大三阳患者肝细胞损伤与6项免疫指标相关性探讨

目的探讨乙型肝炎大三阳患者肝细胞损伤与血清IgM、IgG、IgA、C3、C4及C反应蛋白（CRP）变化的关系。方法选择乙肝大三阳患者80例，根据丙氨酸氨基转移酶（ALT）值（ALT〉200IU／L和〈40IU／L）分为甲、乙两组，各40例，采用速率散射比浊法测定血清IgM、IgG、IgA、C3、C4及CRP。结果甲组血清IgA、IgG、CRP均高于乙组，两组差异具有统计学意义（P〈0．05）；血清IgM、C3、C4两组差异无统计学意义（P〉0．05）。结论血清IgA、IgG、CRP有助于评估肝细胞损伤程度。     

Effect of analytical factors on immunochemical reference limits for complement component C3 in serum of a reference pediatric population.

We evaluated analytical factors such as antibody specificity, standard materials, and methodology for the measurement of C3. Mancini-type radial immunodiffusion and immunonephelometry were shown to give comparable data if variables other than procedural variables are eliminated. The most significant analytical factors affecting the measurement were antiserum specificity and source of standard material.     

乙肝大三阳患者肝细胞损伤与6项免疫指标相关性探讨

目的探讨乙型肝炎大三阳患者肝细胞损伤与血清IgM、IgG、IgA、C3、C4及C反应蛋白(CRP)变化的关系。方法选择乙肝大三阳患者80例,根据丙氨酸氨基转移酶(ALT)值(ALT>200IU/L和<40IU/L)分为甲、乙两组,各40例,采用速率散射比浊法测定血清IgM、IgG、IgA、C3、C4及CRP。结果甲组血清IgA、IgG、CRP均高于乙组,两组差异具有统计学意义(P<0.05);血清IgM、C3、C4两组差异无统计学意义(P>0.05)。结论血清IgA、IgG、CRP有助于评估肝细胞损伤程度。     

Evaluation of a Behring laser-nephelometer prototype in the measurement of IgG, IgA and IgM.

A helium-neon laser nephelometer prototype manufactured by Hoechst Behring Institut was evaluated and used in our laboratory during a two-month period for the measurement of IgG, IgA and IgM. Two methods of dilution were usedto prepare standard curves. The best results were obtained when the patient serum was diluted one hundred fold (10-100 microliter) and incubated for 15 min at room temperature in a disposable plastic cuvette with the specific antiserum diluted five fold (100-300 microliter). The intensity of the light scattered by the antigen-antibody complexes was then immediately read on the digital voltmeter. The working ranges were 186-5944 mg/dl for IgG, 33-1066 mg/dl for IgA and 17-545 mg/dl for IgM. Standard curves obtained for the three immunoglobulins on six different days could be superimposed perfectly demonstrating an excellen reproducibility. The coefficient of variation for IgG (n = 8) was 4.1% at 5800 mg/dl. The results (n = 37) produced by the laser nephelometer (y) correlated very well with those obtained by radial immunodiffusion (x) for: IgG y = 8.07 + 1.00 X, r = 0.997, IgA y = - 6.51 + 1.05 X, r = 0.996, IgM y = 3.35 + 0.98 X, r = 0.998.     

Antibiodies of the IgG, IgM, and IgA classes in newborn and adult sera reactive with gram-negative bacteria

Umbilical cord serum and adult serum antibodies reactive with heat-stable somatic antigens of Gram-negative bacteria (Neisseria gonorrhoeae, Escherichia coli, and Salmonella typhosa) were assayed by using an indirect fluorescent antibody test. Reactive IgG, IgM, and IgA antibodies were identified by using fluoresceinconjugated antisera specific for these immunoglobulin classes.IgG antibody titers in cord serum approximated those found in the corresponding maternal sera. IgM and IgA antibodies were present in adult sera but were not demonstrable or were present only in small amounts in cord sera. The presence of IgG and IgM antibodies reactive with Gram-negative bacteria was confirmed by the testing of purified 7S and 19S fractions. In addition, both IgG and IgM reactivities were inhibited by the prior incubation of serum with purified specific lipopolysaccharide preparations.The ubiquity and magnitude of these natural IgG antibodies in the sera of both adults and neonates have apparently eluded detection in previous studies. The use of bactericidal and agglutination tests, which are apparently more sensitive to the presence of IgM than to IgG antibodies, may account for the failure of previous studies to detect adult and cord IgG antibodies reactive with somatic antigens of Gram-negative bacteria. The presence of these IgG antibodies may be correlated with the resistance to infection demonstrated by most newborns as they are challenged by the septic extrauterine environment.     

Sources of variation and reference intervals for serum cystatin C in a healthy Japanese adult population.

BACKGROUND: To derive reference intervals (RIs) for cystatin C (CysC), we examined sources of variation in its serum concentration by multiple regression analysis. METHODS: A total of 596 healthy subjects (30-75 years of age) who underwent an annual health check were chosen as candidate reference individuals who did not have any chronic illness requiring medication. Serum CysC was measured together with routine screening tests (basic clinical chemistry and complete blood count). RESULTS: Multivariate analysis revealed that CysC concentrations were higher in males by an average of 0.082 mg/L. Levels were positively associated with age (+0.047 mg/L for every 10 years), body fat (BF%) and cigarette smoking, and negatively associated with alcohol consumption. A subgroup analysis revealed that the gender difference was not significant for those over 50 years of age. RIs were determined using a "latent abnormal values exclusion method" involving deletion of individuals with two or more abnormal results in the screening tests. RIs were partitioned into three categories by age and gender: 0.60-0.95 mg/L for males aged 30-50 years; 0.55-0.84 mg/L for females aged 30-50 years; and 0.64-1.05 mg/L for all subjects aged 51-75 years. Creatinine levels showed little age-related change, but a conspicuous gender difference; they increased with body weight, but not with BF%. CONCLUSIONS: In interpreting serum CysC levels, BF%, cigarette smoking, and alcohol consumption may need to be considered, in addition to age and gender, as sources of variation.     

SARS-CoV-2疫苗接种成人血清SARS-CoV-2IgM抗体、IgG抗体和中和抗体水平分析

目的 评估成人接种严重急性呼吸综合征冠状病毒2(SARS-CoV-2)疫苗后SARS-CoV-2 IgM、IgG和中和抗体的形成情况.方法 选取接受SARS-CoV-2疫苗接种的成人80名(疫苗接种组),检测疫苗接种完成后7 d内和第14天的血清SARS-CoV-2 IgM抗体、IgG抗体及中和抗体水平.以未接种SAR...