Homogeneous, liposome-based assay for total complement activity in serum.

1986 ◽  
Vol 32 (2) ◽  
pp. 275-278 ◽  
Author(s):  
D W Bowden ◽  
M Rising ◽  
G Akots ◽  
A Myles ◽  
R J Broeze
Keyword(s):  
Normal Population ◽  
Test Results ◽  
Normal Range ◽  
Serum Samples ◽  
Complement Components ◽  
Complement Activity ◽  
Standard Curve ◽  
Total Complement ◽  
Speed Accuracy ◽  
Range Test

Abstract This is a rapid, homogeneous, liposome-based assay for total complement activity in human serum. Liposome-encapsulated enzyme is unmasked by the action of complement on liposomes carrying surface-bound immune complexes. The amount of unmasked enzyme, proportional to the concentration of added complement, is quantified by measuring the absorbance of enzymically produced product at 410 nm. Complement activity in serum samples is extrapolated from a standard curve generated from dilutions of a guinea pig serum containing a known activity of complement. Interassay CVs were less than 7.0% and intra-assay CVs less than 2.8% for serum pools with complement activities spanning the normal range. Test results correlate as well with those of the hemolytic complement test (r = 0.80) as the latter correlates with itself (r = 0.82), and also correlate reasonably with measurements of complement components C3 (r = 0.62) and C4 (r = 0.74). Values for a normal population are reported. Advantages of this test include stability of reagents, speed, accuracy, simplicity, and avoidance of radioisotopes.

scholarly journals A Flow Cytometry-Based Assay for the Measurement of Total Complement Activity in the Serum and Clinical Practice

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
Xuewei Ding ◽  
Shijun Li ◽  
Hui Liu
Keyword(s):  
Flow Cytometry ◽  
Nephrotic Syndrome ◽  
Linear Relationship ◽  
High Volume ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Complement Activity ◽  
Significant Difference ◽  
Cell Groups ◽  
Total Complement

Objective. To develop a novel sensitive and accurate assay suitable for high-volume testing of the total complement activity in the serum for clinical laboratories. Methods. The total complement activity (TCA) to be measured was quantified by detecting the number of fragments produced by erythrocyte lysis and the erythrocyte fragmentation index (EFI), indicating TCA. EFI = M × M 2 / M 1 + M 2 , where M is the number of erythrocyte fragments (removed from the background), M 1 is the number of unagglutinated red cells, M 2 is the number of agglutinated red cell groups, and M 2 / M 1 + M 2 is the agglutination coefficient indicating the degree of erythrocyte agglutination. Mild changes in hemolysin and erythrocyte concentrations were made to optimize the testing conditions. The same serum samples were tested for 10 consecutive days to determine the stability of the experimental results. Serum EFI was detected in both nephrotic syndrome patients and healthy subjects. Results. There was a linear relationship between hemolysin and erythrocyte agglutination ( r = 0.999 , P < 0.001 ). A good linear relationship existed between EFI and TCA ( r = 0.991 , P < 0.001 ). The results were not affected by slight fluctuations in the concentrations of hemolysin or erythrocytes. The interbatch CV = 8.6 % of the test results showed good stability. There was a significant difference in the EFI between nephrotic syndrome patients and healthy individuals, P < 0.001 , and EFI was reduced in nephrotic syndrome patients compared to healthy individuals. Conclusion. The flow cytometry-based assay for TCA was sensitive and accurate and had potential value for clinical application.

Turbidimetry of rheumatoid factor in serum with a centrifugal analyzer.

1986 ◽  
Vol 32 (1) ◽  
pp. 124-129 ◽  
Author(s):  
L Borque ◽  
M Yago ◽  
C Mar ◽  
C Rodriguez
Keyword(s):  
Rheumatoid Arthritis ◽  
Human Serum ◽  
Rheumatoid Factor ◽  
Test Results ◽  
Serum Samples ◽  
Human Igg ◽  
Standard Curve ◽  
Igm Rheumatoid Factor ◽  
Triglyceride Concentration ◽  
Reference Serum

Abstract We describe the simple, rapid turbidimetry of IgM rheumatoid factor in human serum by use of the Cobas-Bio centrifugal analyzer. Heat-aggregated human IgG is used as the antigen. The immunoturbidimetric reaction is monitored at 340 nm for 300 s, and the changes in absorbance after the antigen is added are used to prepare the standard curve. Test results are calculated from the stored curve and reported in int. units/mL, based on comparison with the WHO reference serum for rheumatoid factor. There is no interference from bilirubin (up to 340 mumol/L) or hemoglobin (up to 5600 mg/L). Serum samples with a triglyceride concentration greater than 2.20 mmol/L must be cleared of lipids before analysis. The standard curve is linear from 30 to 500 int. units/mL. Precision, accuracy, linearity, and sensitivity are quite acceptable. The CV was generally less than 5% for different concentrations of rheumatoid factor. Results agree well with those by a rate-nephelometric procedure on the Beckman ICS system (rs = 0.932). However, both correlate poorly with a modified classical Waaler-Rose test. Of 47 patients with rheumatoid arthritis, 34 had IgM rheumatoid factor in their serum, but the measured value did not reflect the activity of the disease.

Interpreting clinical and laboratory tests: importance and implications of context

Diagnosis ◽  
2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Alan N. Charney ◽  
Jordan T. Dourmashkin
Keyword(s):  
Laboratory Tests ◽  
Physiological Condition ◽  
Clinical Medicine ◽  
Normal Values ◽  
Reference Interval ◽  
Reference Intervals ◽  
Test Results ◽  
Normal Range ◽  
Behavioral Diversity ◽  
Range Test

AbstractClinical and laboratory tests in clinical medicine include a range of measurements that may be categorized as “normal range” tests, positive or negative tests, or contextual tests. Normal range test results are quantitative and are compared to a reference interval or range provided by the laboratory. Positive or negative tests are also quantitative tests and characteristically have a cutoff value that specifies the result. Contextual tests require a context, a physiological condition, to correctly interpret the result. A closer examination of reference intervals suggests that these also are contextual. The fact that there is a range of apparently normal values indicates the presence of cultural, biological, physiological and behavioral diversity in the population sampled to determine normality. As such, the reference interval describes the population from which it was determined and may have utility in this regard.

Immunoglobulins and Complement in Migraine

Cephalalgia ◽  
1983 ◽  
Vol 3 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Antoni Jerzmanowski ◽  
Andrzej Klimek
Keyword(s):  
Complement System ◽  
Alternative Pathway ◽  
Control Group ◽  
Immunoglobulin Level ◽  
Normal Range ◽  
Complement Activity ◽  
Complement Level ◽  
Total Complement ◽  
Alternative Pathway Of Complement

In 54 patients with migraine and 70 persons comprising the control group, the total complement level (CH50) was evaluated together with its C3 and C4 fraction level and the level of IgG, IgA and IgM immunoglobulins. It was found that the average C3 fraction level was significantly decreased, while the C4 fraction level and total complement activity remained in the normal range. The immunoglobulin level did not show any statistically significant alterations except for the IgA level, which was lowered in migraine patients. On this basis, i.e. lowering of the C3 fraction level with normal C4 fraction level and total complement activity and lack of elevation of IgA, it is felt that the alternative pathway of complement system may be activated in migraine.

Vestibular Function and Motion Sickness Susceptibility: Videonystagmographic Evidence From Oculomotor and Caloric Tests

2020 ◽  
Vol 29 (2) ◽  
pp. 188-198
Author(s):  
Cynthia G. Fowler ◽  
Margaret Dallapiazza ◽  
Kathleen Talbot Hadsell
Keyword(s):  
Phase Velocity ◽  
Motion Sickness ◽  
Repeated Measures ◽  
Short Form ◽  
Vestibular Function ◽  
Slow Phase ◽  
Test Results ◽  
Normal Range ◽  
Slow Phase Velocity ◽  
Caloric Tests

Purpose Motion sickness (MS) is a common condition that affects millions of individuals. Although the condition is common and can be debilitating, little research has focused on the vestibular function associated with susceptibility to MS. One causal theory of MS is an asymmetry of vestibular function within or between ears. The purposes of this study, therefore, were (a) to determine if the vestibular system (oculomotor and caloric tests) in videonystagmography (VNG) is associated with susceptibility to MS and (b) to determine if these tests support the theory of an asymmetry between ears associated with MS susceptibility. Method VNG was used to measure oculomotor and caloric responses. Fifty young adults were recruited; 50 completed the oculomotor tests, and 31 completed the four caloric irrigations. MS susceptibility was evaluated with the Motion Sickness Susceptibility Questionnaire–Short Form; in this study, percent susceptibility ranged from 0% to 100% in the participants. Participants were divided into three susceptibility groups (Low, Mid, and High). Repeated-measures analyses of variance and pairwise comparisons determined significance among the groups on the VNG test results. Results Oculomotor test results revealed no significant differences among the MS susceptibility groups. Caloric stimuli elicited responses that were correlated positively with susceptibility to MS. Slow-phase velocity was slowest in the Low MS group compared to the Mid and High groups. There was no significant asymmetry between ears in any of the groups. Conclusions MS susceptibility was significantly and positively correlated with caloric slow-phase velocity. Although asymmetries between ears are purported to be associated with MS, asymmetries were not evident. Susceptibility to MS may contribute to interindividual variability of caloric responses within the normal range.

Immunologic Assessment of Patients Treated with Bovine Fibrin as a Hemostatic Agent

1996 ◽  
Vol 76 (06) ◽  
pp. 0925-0931 ◽  
Author(s):  
John F Carroll ◽  
Keith A Moskowitz ◽  
Niloo M Edwards ◽  
Thomas J Hickey ◽  
Eric A Rose ◽  
...  
Keyword(s):  
Coagulation Factors ◽  
Allergic Reactions ◽  
Factor V ◽  
Normal Range ◽  
Serum Samples ◽  
Human Fibrinogen ◽  
Bovine Thrombin ◽  
Thrombotic Complications ◽  
The Mean ◽  
Clinically Significant

SummaryTwenty-one cardiothoracic surgical patients have been treated with fibrin as a topical hemostatic/sealing agent, prepared from bovine fibrinogen clotted with bovine thrombin. Serum samples have been collected before treatment with fibrin and postoperatively between 1 and 9 days, 3 and 12 weeks, and 6 and 8 months. The titers of anti-bovine fibrinogen antibodies, measured by ELISA specific for immunoglobulins IgG or IgM, increased to maximal values after about 8 or 6 weeks, respectively. After 8 months, IgG titers were on average 20-fold lower than the mean maximal value, while IgM titers returned to the normal range. IgG was the predominant anti-bovine fibrinogen immunoglobulin as documented by ELISA, affinity chromatography and electrophoresis. Anti-bovine fibrinogen antibodies present in patients reacted readily with bovine fibrinogen, but did not cross-react with human fibrinogen as measured by ELISA or by immunoelectrophoresis. A significant amount of antibodies against bovine thrombin and factor V has been found, many cross-reacting with the human counterparts. No hemorrhagic or thrombotic complications, or clinically significant allergic reactions, occurred in any patient, in spite of antibody presence against some bovine and human coagulation factors. The treatment of patients with bovine fibrin, without induction of immunologic response against human fibrinogen, appeared to be an effective topical hemostatic/sealing measure.

Effects of X-Ray Exposure on Some CMI Regulatory Cytokines in Technicians Serum Samples

2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Weam S Al-Hamadany
Keyword(s):  
Clinical Status ◽  
Cell Mediated Immunity ◽  
Normal Range ◽  
Serum Samples ◽  
X Ray ◽  
Immunosuppressive Factor ◽  
Elisa Technique ◽  
Immunological Process ◽  
Field Workers ◽  
Tomography Scan

Ionizing radiation considered as an immunosuppressive factor upon over dose of exposure. Radiation field workers usually following a periodic checkup to monitor changes in their clinical status. Cell Mediated Immunity (CMI) has an important cytokines that regulate this specific immunological process. This study estimated the Interleukins (IL-2, IL-12 and IL-18) levels in serum samples using ELISA technique. Serum samples were collected from X-ray Technicians (Radiography, Fluoroscopy and Computed Tomography Scan Technicians) working in AL-Muthanna governorate hospitals. A total of (60) technicians and (30) control were involved in this research. Results showed significant decrease in IL-2 levels and increase in IL-18 levels in test groups (technicians) as compared with controls. While, IL-12 levels did not show a difference; all obtained values were within normal range. Overdose of X-ray exposure caused CMI suppression via disturbing the levels of critical cytokines (IL-2 and IL-18) leading to CMI loss regulation.

scholarly journals Atypical anti-glomerular basement membrane disease with anti-GBM antibody negativity and ANCA positivity: a case report

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Na Guo ◽  
Qinghua Yin ◽  
Song Lei ◽  
Yanjun He ◽  
Ping Fu
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Rare Case ◽  
Test Results ◽  
Serum Samples ◽  
Tissue Samples ◽  
Case Presentation ◽  
Severe Renal Insufficiency ◽  
Laboratory Test Results ◽  
Organ Specific

Abstract Background Anti-glomerular basement membrane (anti-GBM) disease is an organ-specific autoimmune disease that involves the lung and kidneys and leads to rapid glomerulonephritis progression, with or without diffuse alveolar hemorrhage, and even respiratory failure. Classic cases of anti-GBM disease are diagnosed based on the presence of the anti-GBM antibody in serum samples and kidney or lung biopsy tissue samples. However, atypical cases of anti-GBM disease are also seen in clinical practice. Case presentation We herein report the rare case of a patient with atypical anti-GBM disease whose serum was negative for the anti-GBM antibody but positive for the myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (p-ANCA) and another atypical ANCA. Laboratory test results showed severe renal insufficiency with a creatinine level of 385 μmol/L. Renal biopsy specimen analysis revealed 100% glomeruli with crescents; immunofluorescence showed immunoglobulin G (IgG) linearly deposited alongside the GBM. Finally, the patient was discharged successfully after treatment with plasmapheresis, methylprednisolone and prednisone. Conclusion This patient, whose serum was negative for the anti-GBM antibody but positive for p-ANCA and another atypical ANCA, had a rare case of anti-GBM disease. Insights from this unusual case might help physicians diagnose rare forms of glomerulonephritis and treat affected patients in a timely manner.

Pediatric reference interval verification for endocrine and fertility hormone assays on the Abbott Alinity system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mary Kathryn Bohn ◽  
Siobhan Wilson ◽  
Alexandra Hall ◽  
Khosrow Adeli
Keyword(s):  
Clinical Decision Making ◽  
De Novo ◽  
Reference Interval ◽  
Clinical Decision ◽  
Reference Intervals ◽  
Healthy Children ◽  
Confidence Limits ◽  
Test Results ◽  
Serum Samples ◽  
Abbott Architect

Abstract Objectives The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) has developed an extensive database of reference intervals (RIs) for several biomarkers on various analytical systems. In this study, pediatric RIs were verified for key immunoassays on the Abbott Alinity system based on the analysis of healthy children samples and comparison to comprehensive RIs previously established for Abbott ARCHITECT assays. Methods Analytical performance of Alinity immunoassays was first assessed. Subsequently, 100 serum samples from healthy children recruited with informed consent were analyzed for 16 Alinity immunoassays. The percentage of test results falling within published CALIPER ARCHITECT reference and confidence limits was determined. If ≥ 90% of test results fell within the confidence limits, they were considered verified based on CLSI guidelines. If <90% of test results fell within the confidence limits, additional samples were analyzed and new Alinity RIs were established. Results Of the 16 immunoassays assessed, 13 met the criteria for verification with test results from ≥ 90% of healthy serum samples falling within the published ARCHITECT confidence limits. New CALIPER RIs were established for free thyroxine and prolactin on the Alinity system. Estradiol required special considerations in early life. Conclusions Our data demonstrate excellent concordance between ARCHITECT and Alinity immunoassays, as well as the robustness of previously established CALIPER RIs for most immunoassays, eliminating the need for de novo RI studies for most parameters. Availability of pediatric RIs for immunoassays on the Alinity system will assist clinical laboratories using this new platform and contribute to improved clinical decision-making.

scholarly journals Ride through testing of variable speed drive due to voltage sag types (types I, II and III)

2019 ◽  
Vol 10 (2) ◽  
pp. 690
Author(s):  
Surya Hardi ◽  
R. Harahap ◽  
S. Ahmad ◽  
M. Isa
Keyword(s):  
Drop Out ◽  
Dropping Out ◽  
Voltage Sag ◽  
Type I ◽  
Voltage Sags ◽  
Test Results ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Standard Curve ◽  
Test Points

Variable speed drives (VSDs) are widely used in various applications mainly in process industry need constant rotational speed. It is developed from power electronic components thus saving energy in its operation. Unfortunately it is susceptible against power quality problem for example voltage sags. The VSD may be disruption or drop out when it is supplied by voltage sags and it is determined by sag characteristics. This study is to investigate effect of voltage sags Types I, II and III on VSD through laboratory testing. The voltage sags characteristics are generated from voltage sag generator (Shaffner 2100 EMC).  The effects are presented in susceptibility curves in disruption and drop out conditions. The curves resulted are evaluated by standard curve recommended. Test results show that voltage sag Type I cause the VSD disruption only, whereas two types sag other result in the VSD disruption and also drop out. Evaluation results explain  a few test points are in operation area for disruption condition whereas test points for dropping out far below the threshold recommended. Hence the VSD has good quality to voltage sags.

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