Incomplete Antibodies Research Articles

Thrombosis in Antiphospholipid Syndrome: Current Perspectives and Challenges in Laboratory Testing for Antiphospholipid Antibodies.

Antiphospholipid syndrome (APS) diagnosis hinges on identifying antiphospholipid antibodies (aPL). Currently, laboratory testing encompasses lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2-glycoprotein I antibodies (aβ2GPI) IgG or IgM, which are included in the APS classification criteria. All the assays needed to detect aPL antibodies have methodological concerns. LA testing remains challenging due to its complexity and susceptibility to interference from anticoagulant therapy. Solid phase assays for aCL and aβ2GPI exhibit discrepancies between different assays. Antibody profiles aid in identifying the patients at risk for thrombosis through integrated interpretation of all positive aPL tests. Antibodies targeting domain I of β2-glycoprotein and antiphosphatidylserine-prothrombin antibodies have been evaluated for their role in thrombotic APS but are not yet included in the APS criteria. Detecting these antibodies may help patients with incomplete antibody profiles and stratify the risk of APS patients. The added diagnostic value of other methodologies and measurements of other APS-associated antibodies are inconsistent. This manuscript describes laboratory parameters useful in the diagnosis of thrombotic APS and will concentrate on the laboratory aspects, clinical significance of assays, and interpretation of aPL results in the diagnosis of thrombotic APS.

Challenges in laboratory testing of patients suspected of antiphospholipid syndrome: practical implications for clinicians.

This paper focuses on the laboratory tests necessary for the diagnosis of antiphospholipid syndrome (APS). Diagnosis starts with the selection of patients suspicious of having APS. The timing related to the clinical event is important to avoid false classification of APS patients. For the interpretation of the test results of antiphospholipid antibodies (aPL) understanding of all pitfalls and interferences is necessary. Lupus anticoagulant (LA) measurement remains a complex procedure with many pitfalls and interferences. The effect of anticoagulant therapy, the main confounder of LA measurement, can be overcome by removal agents for direct oral anticoagulants (DOAC) or by considering assays as Taipan snake venom time / Ecarin clotting time not affected by antivitamin K therapy and anti-Xa DOAC. However, both procedures have limitations. Solid-phase assays for anticardiolipin antibodies (aCL) and anti-β2-glycoprotein 1 antibodies (aβ2GPI) show inter-assay differences. Diagnosis is based on the measurement of three groups of aPL: LA, aCL and aβ2GPI, of IgG and IgM isotype. This allows to make antibody profiles that helps in identifying patients at risk. Other aPL, such as antibodies against the domain I of β2GPI and anti-phosphatidylserine-prothrombin antibodies may be useful in risk stratification of APS patients and in some specific situations of patients with incomplete antibody profile, but are not needed for diagnosis. Laboratory diagnosis of APS remains challenging. To increase the diagnostic efficacy and reliability, an integrated interpretation of all results and an interpretative comment should be provided on the laboratory report. Therefore, a close interaction between clinical pathologists and clinicians is mandatory.

IgMAT: immunoglobulin sequence multi-species annotation tool for any species including those with incomplete antibody annotation or unusual characteristics

BackgroundThe advent and continual improvement of high-throughput sequencing technologies has made immunoglobulin repertoire sequencing accessible and informative regardless of study species. However, to fully map dynamic changes in polyclonal responses precise framework and complementarity determining region annotation of rearranging genes is pivotal. Most sequence annotation tools are designed primarily for use with human and mouse antibody sequences which use databases with fixed species lists, applying very specific assumptions which select against unique structural characteristics. For this reason, data agnostic tools able to learn from presented data can be very useful with new species or with novel datasets.ResultsWe have developed IgMAT, which utilises a reduced amino acid alphabet, that incorporates multiple HMM alignments into a single consensus to automatically annotate immunoglobulin sequences from most organisms. Additionally, the software allows the incorporation of user defined databases to better represent the species and/or antibody class of interest. To demonstrate the accuracy and utility of IgMAT, we present analysis of sequences extracted from structural data and immunoglobulin sequence datasets from several different species.ConclusionsIgMAT is fully open-sourced and freely available on GitHub (https://github.com/TPI-Immunogenetics/igmat) for download under GPLv3 license. It can be used as a CLI application or as a python module to be integrated in custom scripts.

A CNN-LASSO ensemble classification model for incomplete antibody reactants screening in coombs test.

Precise classification of incomplete antibody reactants (IAR) in the Coombs test is the primary means to prevent incompatible blood transfusions. Currently, an automatic and contactless method is required for accurate IAR classification to avoid human error. We present an ensemble learning algorithm that integrates five convolutional neural networks and the least absolute shrinkage and selection operator (LASSO) regression algorithm into an IAR intensity classification model. A dataset including 1628 IAR and corresponding labels of IAR intensity categories ((-), (1+), (2+), (3+), and (4+)) was used. We trained the ensemble model using 1302 IAR and validated its performance using 326 IAR. The optimal ensemble model was used to assist immunologists in classifying IAR. The chord diagrams based on the human-machine interaction were established. The ensemble model achieved 98.8%, 98.4%, 99.7%, 99.5%, and 99.4% accuracies in the (-), (1+), (2+), (3+), and (4+) categories, respectively. The results were compared with those of manual classification by immunologists (average accuracy: 99.2% vs. 75.6%). Using the model, all three immunologists achieved increased accuracy (average accuracy: +8.4%). The proposed algorithm can thus effectively improve the accuracy and efficiency of IAR intensity classification and facilitate the automation of haemolytic disease screening equipment.

Seroprevalence of brucellosis among the high-risk population in Ujjain district, Madhya Pradesh

Background: Brucellosis is the most common zoonotic disease caused by Gram-negative coccobacillus belonging to genus Brucella. It is a recognized public health problem in developing countries including India. Aims and Objectives: The aims of these study were to determine the seroprevalance of brucellosis in population having occupation dealing with animals and thus are in close contact of animals. Materials and Methods: The study was conducted in semi-urban areas of central India. Blood samples were collected from personnel working in slaughter houses, meat shops, and veterinarians and their close contact and who are willing to participate in study. A total 102 samples collected randomly from butchers (n=20), veterinarians (n=29), and animal handlers (n=53) and were tested for Brucella abortus and Brucella melitensis by a commercial kit which allows the detection of both complete (IgG and IGM) and incomplete antibodies. Results: A total 102 subjects were included in the study and overall prevalence of brucellosis among high-risk group was found to be 2.9%. One veterinarian doctor was also found positive for both B. melitensis and B. abortus. Highest prevalence of brucellosis was found in veterinarians (6.8%) followed by animal handlers (1.8%), and none of the butcher was tested positive for any of the Brucella antibody. Conclusion: The present study screened all possible known high-risk groups for brucellosis and revealed that veterinarians have high chances of getting the infection. Occupation-related disease like brucellosis needs regular surveillance and integration into control and prevention program at a local and national level.

Solid Phase Assays for Antiphospholipid Antibodies.

The diagnosis of antiphospholipid syndrome (APS) relies on the detection of circulating antiphospholipid antibodies (aPL). Currently, lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2-glycoprotein I antibodies (aβ2GPI) IgG or IgM are the laboratory criteria if persistently present over time. As aCL and aβ2GPI are two out of the three laboratory criteria, the detection of aPL by solid phase assays is an essential step in the diagnosis of APS. Advancement has been made to resolve some of the methodological challenges of aCL and aβ2GPI assays by providing guidelines how to measure aPL, as well as to gain a better understanding of their diagnostic role. However, solid phase assays for aCL and aβ2GPI still show substantive inter-assay differences, resulting in disagreement concerning positive/negative results, but also differences in titer of antibodies. This hampers the semiquantitative classification into low-medium-high positivity. The non-criteria aPL, such as antibodies against the domain one of β2GPI and anti-phosphatidylserine/prothrombin antibodies (aPS/PT) have roles in confirming the risk in APS, and can be useful, especially in patients with incomplete antibody profiles.

Convolutional neural network-based automatic classification for incomplete antibody reaction intensity in solid phase anti-human globulin test image.

The precise classification of incomplete antibody reaction intensity (IARI) in hydrogel chromatography medium high density medium solid-phase Coombs test is essential for haemolytic disease screening. However, an automatic and contactless method is required for accurate classification of IARI. Here, we present a deep ensemble learning model that integrates five different convolutional neural networks into a single model for IARI classification. A dataset, including 1628 IARI images and corresponding labels of IARI categories ((-), (1 +), (2 +), (3 +), and (4 +)), was used. We trained our model using 1302 IARIs and validated its performance using 326 IARIs. The proposed model achieved 100%, 99.4%, 99.4%, 100%, and 100% accuracies in the ( −), (1 +), (2 +), (3 +), and (4 +) categories, respectively. The results were compared with those of manual classification by immunologists (average accuracy: 99.8% vs. 88.3%, p < 0.01). Following model assistance, all three immunologists achieved increased accuracy (average accuracy: + 6.1%), with the average accuracy of junior immunologists maximum increasing by 11.3%. The time required for model classification was 0.094 s·image–1, whereas that required manually was 5.528 s·image–1. The proposed model can thus substantially improve the accuracy and efficiency of IARI classification and facilitate the automation of haemolytic disease screening equipment.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s11517-022-02523-1.

SEROLOGICAL STUDY OF BULGARIAN PATIENTS WITH BRUCELLOSIS

Background: Brucellosis is a widespread zoonotic infection with significant health and socio-economic impacts. This determines the need of a reliable laboratory diagnosis both in endemic areas around the world and in countries where it is rare and under diagnosed. Due to prolongedand hazardous cultivation procedures, the diagnosis is mostly serologically confirmed. Aim: Serological study of Bulgarian citizens with clinical and/or epidemiological data compatible to brucellosis for the period 2005-2015. Materials and methods: Based on clinical and epidemiological data obtained via standard questionnaire 3394 persons suspected for brucellosis along with 106 controls were serologically studied with Rose Bengal slide test, Standard agglutination test, Coombs’ test, Brucellacapt and ELISA. Results: Brucellosis was confirmed in 174 patients. In outbreak related cases the tests listed above were positive in 127 (78.88%), 115 (71.43%), 34 (91.98%), 143 (95.33%) and 104 (96.30%), respectively. A statistically significant positive correlation was found between Coombs’ and Brucellacapt in the studied 55 sera samples (rs = 0,72; p &lt; 0,0000). The profile of anti-Brucella antibodies was investigated in 46 patients with different duration of the disease. In 29 (63.0%) of them the initial serum sample was positive for the three classes of antibodies and in 17 (36.9%) the primary testing didn’t detect IgM, but IgG and IgA. Conclusion: None of the serological tests alone could ensure an accurate diagnosis of brucellosis. It is necessary to use a diagnostic algorithm with appropriately selected serological tests in which Brucellacapt could successfully replace Coombs' test´ for detection of incomplete antibodies in brucellosis with long duration.

Optimization Concentration Control Cell Coombs (CCC) for Validity Tests on Crossmatching Examination

Crossmatching is an examination that needs to be done before doing a blood transfusion to see whether the recipient’s blood is in accordance with the donor’s blood. Validity is done to find out the results obtained in all phases crossmatching tests correctly indicate compatible. Control Coombs Cell (CCC) is a control cell suspension made from group O Rh positive blood which is intentionally coated with an incomplete antibody. The aim is to determine the concentration and optimal time of CCC incubation so that it can be used for validity testing on crossmatching examination. The test used two-way ANOVA test showed significant results, there were differences in the degree of agglutination in variations in concentration and incubation time. The optimum results were not obtained at concentrations of 50 percents, 60 percents, 70 percents and the right incubation time of 15 minutes, 30 minutes, and 60 minutes. The results of agglutination were reduced at a concentration of 50 percents and an incubation time of 15 minutes, that coombs as controlling negative CCC test results and testing serum coombs. CCC as validating results so as not to cause false positive reactions or false negative results.

Role of antiphospholipid antibodies in the diagnosis of antiphospholipid syndrome

The diagnosis of antiphospholipid syndrome (APS) relies on the detection of antiphospholipid antibodies (aPL). Currently, lupus anticoagulant (LA), anticardiolipin (aCL), and antibeta2-glycoprotein I antibodies (aβ2GPI) IgG or IgM are included as laboratory criteria, if persistently present. LAC measurement remains a complicated procedure with many pitfalls and interfered by anticoagulant therapy. Solid-phase assays for aCL and aβ2GPI show interassay differences. These methodological issues make the laboratory diagnosis of APS challenging. In the interpretation of aPL results, antibody profiles help in identifying patients at risk. Other aPL, such as antibodies against the domain I of beta2-glycoprotein (aDI) and antiphosphatidylserine-prothrombin (aPS/PT) antibodies have been studied in the last years and may be useful in risk stratification of APS patients. Because of the methodological shortcomings of immunological and clotting assays, these non-criteria aPL may be useful in patients with incomplete antibody profiles to confirm or exclude the increased risk profile. This manuscript will focus on the laboratory aspects, the clinical relevance of assays and interpretation of aPL results in the diagnosis of APS.

Immunoglobulin Replacement Therapy Versus Antibiotic Prophylaxis as Treatment for Incomplete Primary Antibody Deficiency

BackgroundPatients with an IgG subclass deficiency (IgSD) ± specific polysaccharide antibody deficiency (SPAD) often present with recurrent infections. Previous retrospective studies have shown that prophylactic antibiotics (PA) and immunoglobulin replacement therapy (IRT) can both be effective in preventing these infections; however, this has not been confirmed in a prospective study.ObjectiveTo compare the efficacy of PA and IRT in a randomized crossover trial.MethodsA total of 64 patients (55 adults and 9 children) were randomized (2:2) between two treatment arms. Treatment arm A began with 12 months of PA, and treatment arm B began with 12 months of IRT. After a 3-month bridging period with cotrimoxazole, the treatment was switched to 12 months of IRT and PA, respectively. The efficacy (measured by the incidence of infections) and proportion of related adverse events in the two arms were compared.ResultsThe overall efficacy of the two regimens did not differ (p = 0.58, two-sided Wilcoxon signed-rank test). A smaller proportion of patients suffered a related adverse event while using PA (26.8% vs. 60.3%, p < 0.0003, chi-squared test). Patients with persistent infections while using PA suffered fewer infections per year after switching to IRT (2.63 vs. 0.64, p < 0.01).ConclusionWe found comparable efficacy of IRT and PA in patients with IgSD ± SPAD. Patients with persistent infections during treatment with PA had less infections after switching to IRT.Clinical ImplicationGiven the costs and associated side-effects of IRT, it should be reserved for patients with persistent infections despite treatment with PA.

Серологічно слабкий D-фенотип: огляд та інтерпретація групи крові RhD

The Rhesus system is the second most important erythrocyte system for transfusion after ABO. Accurate determination of the Rhesus status of the donor, recipient, pregnant allows to prevent the development of post-transfusion hemolytic complications of the fetus or newborn associated with incompatibility of the blood of the mother and the fetus by D antigen. Generally, determination of the Rhesus affiliation of a person is performed by serological methods using anti-Rhesus reagents with full or incomplete antibodies. However, the results of serological studies are not always clear. Mutations and other effects of the RH gene locus disrupt the production of the normal D antigen and lead to the emergence of numerous varieties of antigen D. The variant of antigen D was described in 1946 and was designated as Du. The study showed that the differences between Du antigen and normal D were quantitative rather than qualitative. The Du antigen was later designated as Dweak - a weak D-antigen or a weak D-phenotype. In the early 1950s, anti-D antibodies were detected in recipients with a weak D-antigen after transfusion with Rh-positive blood and in pregnant women with the Du phenotype during pregnancy and at the birth of a D+ baby. It was suggested that the D antigen was not homogeneous and consisted of numerous partial variants: D1, D2, D3, etc. A complete set of partial variants corresponds to a complete D-antigen. The absence of any of one or more partial factors leads to the appearance of attenuated forms of the D antigen, denoted as Dpartial. People lacking certain partial antigens can produce anti-D antibodies against them. Differentiation of weak D phenotypes has great clinical importance, because transfusion of Rh-erythrocytes to recipients with Dweak and who are actually Rh-positive, has no scientific justification and leads to unjustified consumption of deficient blood and unnecessary immunoprophylaxis of anti-Rh immunoglobulin to pregnant women. International laboratory practice has no unified policy regarding the diagnosis of weak variants of D antigen and the interpretation of the results. Polymerase chain reaction allows to accurately define the Rh status of an individual and to avoid unreasonable transfusions of Rh-negative blood and unnecessary immunoprophylaxis

IMMUNE ANTIBODIES IN MOKSHA AND ERZYA ETHNIC GROUPS OF THE REPUBLIC OF MORDOVIA

ABO system's immune antibodies are common, but not as persistent as natural anti-A and anti-B antibodies. They are the result of hyper immunization of an iso- or heteroimmune nature and belong to the IgG class. The study of serum for the presence of immune antibodies of the ABO, Rh system is necessary for the diagnosis of hemolytic disease cases of newborns with ABO, Rh-conflict pregnancy. Clinically significant immune antibodies of erythrocyte systems capable to cause in vivo destruction of red blood cells are of great importance in transfusiology and immunohematology. The most common cause of their occurrence is alloimmunization with red blood cell antigens during childbirth. The aim of this study was to determine the characteristics of the immune anti-erythrocyte antibodies in residents of the Republic of Mordovia belonging to the ethnic groups of Moksha and Erzya. Methods. The cross-sectional study involved 294 people from the Moksha and 387 people and Erzya ethnic groups, randomly selected in 7 districts of the Republic of Mordovia. Detection of IgG anti-A, anti-B ABO systems was performed by inactivation of disulfide bonds in IgM molecules using a 5 % unitiol solution and then by direct agglutination method at indoor temperature with standard red blood cells of group O(I), A(II), and B(III). The study of incomplete anti-erythrocyte antibodies of other systems was performed by indirect Coombs' test using gel technology. Results. The study of immune antibodies of the ABO system revealed from 10.61 to 16.00 % of anti-A antibodies and from 2.27 to 6.38 % of anti-B antibodies in both men and women Moksha and Erzya. We studied immune anti-erythrocyte antibodies: anti-D 0.34 % in Moksha and anti-D 0.26% and anti-Kell 0.26 % antibodies in Erzya. The scale of immunogenicity of red blood cell antigens in the studied groups: A&gt;, B&gt;, D&gt; and K&gt;. The alloimmunization index of transfusion-hazardous antigens was calculated as 0.34 for Moksha and 0.52 for Erzya. Conclusions. Physiologically, the immune system in Moksha and Erzya actively reacts with antibody's production and it is sensitive to immunization by the group of antigens.

P766 Elegibility for CLOSE and REDUCE trials of real world patients with Transient Ischemic Attack (TIA) or Acute Ischemic Stroke (AIS) and Patent Foramen Ovale (PFO)

Abstract Introduction In the last decade there has been an intense discussion in which therapeutic option is most suitable for patients with TIA or cryptogenic AIS and a PFO. Recently two randomised studies (CLOSE and REDUCE) have been published tackling this question. Both have showed preference in lower recurrence rates in the group assigned for PFO closure. The eligibility criteria of these types of studies frequently are very restricted, becoming difficult to ascertain the best therapeutic option for a large number of patients. Goal Analyse a real world cohort of patients with TIA or cryptogenic AIS with PFO and identify the eligibility of these patients for the inclusion in the CLOSE and REDUCE trials. Methods We made a retrospective observational analysis of a cohort of patients discussed in a multidisciplinary meeting (Cardiology and Neurology departments) of our Hospital in which is made the decision of PFO closure vs conservative management between November 2017 and November 2018. We included all the patients with probable TIA or AIS and PFO. Demographic, clinical, image and therapeutic data was registered. The inclusion and exclusion criteria used in CLOSE and REDUCE trial were applied. Results 25 patients were analysed, 56.0% (n = 14) were male. Median age of 47 years. Median RoPE score 7. The commonest cardiovascular risk factors were hypertension (36.0%, n = 9) and smoking (28.0%, n = 7). Eight patients met criteria for cortical cryptogenic AIS, three had lacunar strokes, two had TIA with findings in cerebral imaging and twelve presented with TIA without findings in cerebral imaging. Transesophagic echocardiography was performed in 92.0% (n = 23) of patients, transthoracic echocardiography with bubble study was performed in two cases. At the time of data collection, six patients were waiting completion of the workup. PFO closure was performed in three cases. Closure was proposed in other two. When applying the eligibility criteria of CLOSE and REDUCE the main reasons for exclusion in the REDUCE trial were TIA without cerebral imaging (48.0%, n = 12), incomplete antiphospholipid antibody syndrome screening (36.0%, n = 9) and age greater than 59 years (28.0%, n = 7). The main reasons for exclusion in the CLOSE trial were TIA without cerebral imaging (48.0%, n = 12), age greater than 60 years (28%, n = 7) and failing to meet the designated echocardiography criteria (20.0%, n = 5). Conclusion 2 real world patients met eligibility criteria for the REDUCE trial and 3 for CLOSE. The main reason for exclusion in both REDUCE and CLOSE was TIA without cerebral imaging (48.0% n = 12). Older patients, and patients with a prothrombotic condition were also excluded. Multidisciplinary meetings are essential to ascertain the most beneficial therapeutic option for these patients. It is our believe that the management of risk factors should be similar in a TIA and a AIS and also that the presence of a prothrombotic condition should favor the closure of PFO.

A new reliable test for crossmatching: microplate hydrogel immunoassay technology

To provide a novel assay to detect incomplete antibodies in the crossmatching test. There is a requirement in China that both major and minor crossmatch tests are required. Among all methods of crossmatching, the tube anti-human globulin test requires tedious washing steps and is time-consuming, whereas the microcolumn gel immunoassay anti-human globulin test is susceptible to sample quality. The process of the microplate hydrogel immunoassay anti-human globulin test involves the use of our patented hydrogel chromatography medium and U-bottom microplates pre-coated with goat anti-human globulin (AHG). A mixture of red blood cells (RBCs) and serum is centrifuged through the hydrogel under precise conditions. In incompatible reactions, the sensitised RBCs are captured by the pre-coated AHG and form a layer over the bottom of the well, whereas in compatible reactions, the unbound RBCs form a button at the bottom of the well. The sensitivity of this new approach and the performance when testing old specimens were evaluated. This approach was more convenient and slightly more sensitive than the tube anti-human globulin test and was superior to the microcolumn gel immunoassay when testing old specimens. In general, this assay is suitable for the routine clinical use of crossmatching to detect incomplete antibodies.

Contribution from the laboratory in the diagnosis of heparin-induced thrombocytopenia. A case study

The diagnosis of antiphospholipid syndrome (APS) relies on the detection of antiphospholipid antibodies (aPL). Currently, lupus anticoagulant (LA), anticardiolipin (aCL), and antibeta2-glycoprotein I antibodies (aβ2GPI) IgG or IgM are included as laboratory criteria, if persistently present. LAC measurement remains a complicated procedure with many pitfalls and interfered by anticoagulant therapy. Solid-phase assays for aCL and aβ2GPI show interassay differences. These methodological issues make the laboratory diagnosis of APS challenging. In the interpretation of aPL results, antibody profiles help in identifying patients at risk. Other aPL, such as antibodies against the domain I of beta2-glycoprotein (aDI) and antiphosphatidylserine-prothrombin (aPS/PT) antibodies have been studied in the last years and may be useful in risk stratification of APS patients. Because of the methodological shortcomings of immunological and clotting assays, these non-criteria aPL may be useful in patients with incomplete antibody profiles to confirm or exclude the increased risk profile. This manuscript will focus on the laboratory aspects, the clinical relevance of assays and interpretation of aPL results in the diagnosis of APS.

LOW CONCENTRATIONS OF HEPATITIS C VIRUS RNA IN SEROLOGICALLY MILD INFECTION

Occult HCV infection (OCI) provides significant interest recently. HCV RNA in this case can be detected not in plasma, but in blood cells and/or in liver tissue. In case of antibody genesis impairment anti-HCV detection may lead to negative or "uncertain" result. The aim of the study was to estimate infection type in blood donors and patients with hematological diseases by exploration of samples with uncertain anti-HCV detection results. Blood samples of 30 180 potential blood donors' and 4322 patients with hematological diseases were tested. Comparative analysis of wide pattern of HCV markers was performed. 33 blood donors and 42 patients were enrolled in follow-up examination. Uncertain results of Anti-HCV detection in donors' samples were in 0.18% of cases. Follow-up examination of 33 donors provided discordant results using immunochemiluminescence assay and ELISA. 15.2% donors' samples contained HCV RNA in low concentration. Follow-up observation of 42 patients with incomplete antiviral antibody pattern showed HCV RNA presence in 40.5% cases (21.4% high viremia and 19.0% low viremia). Samples with low RNA concentration contained low titers of anti-core antibodies. Samples with high titers of anti-core antibodies contained high HCV RNA level. Uncertain results of anti-HCV in 15.2% of potential blood donors' samples were confirmed by detection of HCV RNA in low concentration. It proved OCI presence in these individuals and called for testing for wide pattern of HCV markers in addition to routine screening. Patients with hematological diseases showed low level of HCV RNA along with low titers of antibodies against one or two viral antigens.

Novel autoantibodies in Sjögren's syndrome: A comprehensive review.

Sjögren's syndrome is a systemic autoimmune disease characterized by immune- mediated injury of exocrine glands, as well as a diverse array of extraglandular manifestations. B cell over-activation is a key feature of the disease, attested by the wide spectrum of autoantibodies detected in these patients. Up to date, anti- Ro/SSA and anti-La/SSB antibodies are traditional biomarkers for disease classification and diagnosis. On the other hand, the detection of novel autoantibodies in SS has increased in the last years, opening a window of opportunity to denote particular stages of the disease, to establish clinical phenotypes, and to predict long-term complications such as lymphoma. For instance, anti-SP-1, anti-CA6 and anti-PSP antibodies occur in an earlier stage than anti-Ro/La antibodies, and may identify a subset of primary Sjögren's syndrome patients with mild or incomplete disease, whereas anti-cofilin-1, anti- alpha-enolase and anti-RGI2 antibodies are potential biomarkers of MALT lymphoma. Antibody detection is also important to elucidate new aspects of SS pathophysiology, and in the future to permit a phenotype-specific patient approach. Herein we review the literature regarding new autoantibodies in SS and attempt to dissect their usefulness as diagnostic tools, pathogenic role, identification of clinical phenotypes and as predictors of an overlap syndrome.

Incomplete Antibodies May Reduce ABO Cross-Match Incompatibility: A Pilot Study.

Objective:Any erythrocyte transfusion among humans having type A or B blood groups is impossible due to antibodies causing fatal transfusion complications. A cross-match test is performed to prevent immune transfusion complications before transfusion. Our hypothesis is that the fragment antibody (Fab) part of the antibody (incomplete antibody) may be used to prevent an immune stimulus related to the complete antibody. Therefore, we designed a pilot study to evaluate the effectiveness of these incomplete antibodies using cross-match tests.Materials and Methods:Pepsin enzyme and staphylococcal protein A columns were used to cut anti-A and anti-B monoclonal antibodies and purify their Fab (2) fragments, respectively. An Rh-positive erythrocyte suspension with purified anti-A Fab (2) solution and B Rh-positive erythrocyte suspension with purified anti-B Fab (2) solution were combined correspondingly. Cross-match tests were performed by tube and gel centrifugation methods. The agglutination levels due to the anti-A and anti-B Fab (2) antibodies and their effects on the agglutination normally observed with complete antibodies were then measured.Results:No agglutination for the purified incomplete anti-A Fab (2) with A Rh+ erythrocyte and anti-B Fab (2) with B Rh+ erythrocyte combinations was observed in the tube cross-match tests. These agglutination levels were 1+ in two wells in the gel centrifugation cross-match tests. Fab (2)-treated erythrocytes were also resistant to the agglutination that normally occurs with complete antibodies.Conclusion:We determined that the Fab (2) fragments of antibodies may not only be used to obtain a mild or negative reaction when compared to complete antibodies, but they might also be used for decreasing ABO incompatibility. Incomplete antibodies might be a therapeutic option in autoimmune hemolytic anemia and they may also be used in solid organ or hematopoietic stem cell transplantation. Therefore, we have planned an in vivo study to prove these in vitro findings.

Staging of recent HIV-1 infection using Geenius rapid confirmatory assay compared to INNO-LIA, New Lav and Blot 2.2 assays

BackgroundBesides confirmation of HIV seropositivity, Western Blot (WB) assays play an important role for identification of recent infection based on incomplete antibody reactivity and lack of p31 band. ObjectivesWe evaluated the capacities of the Geenius™ HIV1/2 Confirmatory Assay (Bio-Rad), a new generation rapid confirmatory assay based on immune-chromatography and automated reading, for staging of HIV-1 infection. Study designSixteen samples collected during early HIV-1 infections (Fiebig stage III–VI) were tested using the Geenius assay, and compared to HIV Blot 2.2 WB assay (MP Diagnostics), New Lav Blot I WB assay (Bio-Rad) and INNO-LIA™ HIV I/II Score Dot Blot assay (Fujirebio). Results obtained with Geenius and INNO LIA in 47 newly diagnosed chronic HIV-1 infections were also compared. ResultsThe p24 band was less frequently detected in early HIV-1 infections using the Geenius (3/16) compared to the New Lav (15/16, p<0.0001), INNO-LIA (13/16, p=0.0011), and Blot 2.2 (13/16, p=0.0011). Testing samples collected during chronic infection allowed to confirm that p31 band and complete Gag, Pol, Env profiles were less frequently observed using the Geenius assay compared to the INNO LIA assay (p=0.027 for p31, and p=0.0015 for complete profile). ConclusionsThe Geenius assay is a simple and rapid test showing a high sensitivity to detect Env bands and to confirm HIV-1 seropositivity during the early phases of infection. However, this test is less suitable for distinguishing between later stages of acute and chronic infections because of a reduced sensitivity to detect the p31 and p24 bands compared to INNO LIA and New Lav assays.