Importance of human leukocyte antigen antibodies and leukocyte antigen/killer-cell immunoglobulin-like receptor genes in liver transplantation

Many mechanisms have been proposed to explain the hypothetical state of hepatic tolerance,which is described by eventual imbalances or deregulation in the balance of cytokines,mediators,effectors,and regulatory cells in the complex milieu of the liver.In this section,we will comment on the importance of donorspecific anti-human leukocyte antigen(HLA)antibodies(DSA)as well as the compatibility and pairings of HLA and killer-cell immunoglobulin-like receptor(KIR)genotypes in the evolution of liver transplantation.Thus,HLA compatibility,viral infections,and HLA-C/KIR combinations have all been linked to liver transplant rejection and survival.There have been reports of increased risk of acute and chronic rejection with ductopenia,faster graft fibrosis,biliary problems,poorer survival,and even de novo autoimmune hepatitis when DSAs are present in the recipient.Higher mean fluorescence intensity(MFI)values of the DSAs and smaller graft size were associated with poorer patient outcomes,implying that high-risk patients with preformed DSAs should be considered for selecting the graft placed and desensitization methods,according to the investigators.Similarly,in a combined kidney-liver transplant,a pretransplant with a visible expression of several DSAs revealed that these antibodies were resistant to treatment.The renal graft was lost owing to antibody-mediated rejection(AMR).The HLA antigens expressed by the transplanted liver graft influenced antibody elimination.Pathologists are increasingly diagnosing AMR in liver transplants,and desensitization therapy has even been employed in situations of AMR,particularly in patients with DSAs in kidney-hepatic transplants and high-class II MFI due to Luminex.In conclusion,after revealing the negative impacts of DSAs with high MFI,pretransplant virtual crossmatch techniques may be appropriate to improve evolution;however,they may extend cold ischemia periods by requiring the donor to be typed.

HLA antigens and anti-sperm antibody production in Iranian vasectomized men

Dear Editor： Anti-sperm antibodies （ASAs） are composed of numerous antibodies interacting with multiple sperm antigens that play a role in fertility. In males, ASAs cause ＇immune infertility＇ by decreasing sperm counts and normal forms, as well as reducing sperm motility and viability, markedly reducing the likelihood of natural conception. The development of ASA in the male depends on the release of sequestered antigens on germ cells following the disruption of the blood-testis barrier.

A Co-expression System Based on Phage and Phagemid to Select Cognate Antibody-antigen Pairs in vivo

A modified selectively infective phage (SIP) is developed to facilitate the selection of interacting antibody antigen pairs from a large single chain antibody (scFv) library in vivo. The system is constructed with a modified helper phage M13KO7 and phagemid pCANTAB 5 E. The antigen fused to the C terminal of N1 N2 domain and the scFv to the N terminal of CT domain of the gIIIp of filamentous phage are encoded on the phage and phagemid vectors respectively. The phages produced by co transformants restore infectivity via interaction between antigen and antibody fusions in the cell periplasm. In a model system, the scFv fragment of the anti hemagglutinin 17/9 antibody and its corresponding antigen are detected in the presence of a 10 5 fold excess of a non interacting control pairs, which demonstrates this system to be very sensitive and facile to screen a large single chain antibody library.

GENE ENGINEERING EB VIRUS MEMBRANE ANTIGEN IN DETECTION OF MA-IgA ANTIBODY(COMPARISON WITH VCA-IgA AND EA-IgA ANTIBODIES)

With gene engineering EB virus membrane antigen as the diagnostic antigen, indirect immunofluo-rescence (IF) assay was used to detect IgA antibody against EB virus membrane antigen (MA-IgA) in sera from 202 nasopharyngeal carcinoma (NPC) patients and 315 controls (normal and patients with other tumors). MA-IgA antibody was positive in 96.8% of the pretreatment NPC patients with a GMT of 1:36.3. MA-IgA detection by this method was more sensitive than EA-IgA detection by IE. In contrast, patients with tumors other than NPC were negative for MA-IgA antibody. 9.1% of VCA-IgA positive persons were MA-IgA positive with a GMT of less than 1:5. No MA-IgA positive was found in VCA-IgA negatives. The results indicated that this method was relatively specific. In the treatment group, the positive rate and GMT of MA-IgA antibody declined with increase in survival time and the decline was faster than VCA-IgA. When recurrence or distant metastasis developed, similar to VCA-IgA and EA-IgA antibodies, the positive rate and GMT of MA-IgA antibody increased to its pretreatment level. Therefore, MA-IgA detection might be valuable in the early diagnosis and monitor of NPC.

Evaluation of an Innovative Diagnostic Method for Detection of Antibodies and Antigens

Reports manifest a continuing need for the development of rapid and on-site (point of care) assays. Current diagnostic methods commonly used for detection of antibodies and antigens have significant limitations. Scientists at Micro Detect, Inc. have developed an innovative diagnostic device (method) that can be utilized broadly for antibody/antigen interactions including diagnostic assays in the medical, veterinary and food industries. The developed device can be utilized for the detection of antibodies against a single antigen or vice versa. It can also be tailored for specific panels that detect antigens or antibodies for diverse infectious agents, proteins, hormones, tumor markers, autoimmune markers, and allergens. Additionally, it can also be used for detection of toxins, antitoxins, nucleic acids, enzymes, drugs, etc. in both humans and animals. Specimens used in different formats of the device can be tears, saliva, whole blood, serum, plasma, urine, stool, and other bodily discharges. The good intra and inter precisions and acceptable linearity of the device support reliable use of the device. The CV of the device is 1.9% - 2.2%. Likewise, the performance of the device using 92 confirmed negative and positive specimens via a typical assay showed 100% sensitivity, 80% specificity, 96.8% efficacy, 80% positive predictive value, and 100% negative predictive value. The results of our feasibility study suggest reliable utility of a device for rapid, easy-to-use, inexpensive, and on-site (point of care) diagnostic assays. This presents a potential breakthrough in diagnostic methodologies that can be integrated into modern medicine and food industries.

DETECTION OF CANCER-ASSOCIATED ANTIGEN IN FECES USING MONOCLONAL ANTIBODIES IN THE DIAGNOSIS OF COLON CARCINOMA

Monoclonal antibodies against colon and pancreatic cancer, CL-2, CL-3, PS-9, PS-10, were used to detect the associated antigens in feces of patients with gastrointestinal carcinoma and non-cancer diseases. Binding inhibition test by SABC-ELISA method were performed for the measurement of the antigen level. Results showed that the associated antigen detected in feces of patients with colon cancer were significantly higher than that of non-cancer disease or normal subjects. The positive rates were 61.1% as detected with CL-2; 53.4% with CL-3; 55.0%, PS-9; and 53.3% PS-10 in cancer patients while that in normal subjects were 7%; 9%; 8%; and 8% respectively. When 'cocktail' of CL-2, PS-9 and PS-10 were used, the positive rates were 92.5% in colon cancer and 14% in normal subjects. In seven out of the sixty patients with colon cancer studied who were graded as Dukes A, the results were all positive. The results seem superior to the serologic detection and may provide a promising new approach in the early diagnosis of colon cancer.

Adenoviral-mediated localized CTLA-4Ig gene expression induces long-term allograft pancreas survival and donor-specific immune tolerance in rats

T cell activation following alloantigen recognition plays a critical role in the development of the rejection in all solid organ, tissue and cell transplantation. A recombinant molecule, cytotoxic T lymphocyte antigen 4 antibody （CTLA-4Ig）, is known to induce to T-cell into ＂anergy＂ by blocking the costimulatory B7-CD28 interaction. Either systemic or localized administration of CTLA-Ig has been shown to prolong allograft survival and induce donor-specific tolerance in some transplant models. In this study, we characterized the expression and immunosuppressive effectiveness of adenoviral-mediated CTLA-4Ig gene transfer. We demonstrated transduction of the allografts with AdCTLA-4Ig resulted in localized expression, permanent graft survival and stable donor-specific tolerance. In addition, by performing simultaneous dual-organ through a local expression of CTLA-4Ig via adenoviral-mediated transplantation, we targeted on immunosuppression gene transfer into pancreatic allografts.

“Anti-HBc alone” in human immunodefi ciency virus-positive and immuno-suppressed lymphoma patients

Hepatitis B virus (HBV) infection is endemic in various parts of the world. A proportion of patients have resolved prior exposure to HBV, as evidenced by the clearance of circulating hepatitis B surface antigen and the appearance of antibody to hepatitis B core antigen (anti-HBc), which could produce protective antibody to hepatitis B surface antigen (anti-HBs). With time, anti-HBs in some patients may become negative. Such patients are described as having occult HBV infection or "anti-HBc alone". In the context of immunodef icient patients, such as HIV patients or lymphoma patients undergoing immunosuppressive immunotherapy, the lack of protective anti-HBs may increase the risk of hepatitis B reactivation. Serum HBV DNA testing may be necessary in "anti-HBc alone" patients, to detect patients at a high risk of developing HBV infection allowing appropriate prophylactic management.

Hepatitis B virus reactivation during immunosuppressive therapy: Appropriate risk stratification

Our understanding of hepatitis B virus(HBV) reactivation during immunosuppresive therapy has increased remarkably during recent years. HBV reactivation in hepatitis B surface antigen(HBs Ag)-positive individuals has been well-described in certain immunosuppressive regimens, including therapies containing corticosteroids, anthracyclines, rituximab, antibody to tumor necrosisfactor(anti-TNF) and hematopoietic stem cell transplantation(HSCT). HBV reactivation could also occur in HBs Ag-negative, antibody to hepatitis B core antigen(anti-HBc) positive individuals during therapies containing rituximab, anti-TNF or HSCT.For HBs Ag-positive patients, prophylactic antiviral therapy is proven to the effective in preventing HBV reactivation. Recent evidence also demonstrated entecavir to be more effective than lamivudine in this aspect. For HBs Ag-negative, antiHBc positive individuals, the risk of reactivations differs with the type of immunosuppression. For rituximab, a prospective study demonstrated the 2-year cumulative risk of reactivation to be 41.5%, but prospective data is still lacking for other immunosupressive regimes. The optimal management in preventing HBV reactivation would involve appropriate risk stratification for different immunosuppressive regimes in both HBs Ag-positive and HBs Ag-negative, anti-HBc positive individuals.

Characterization and potential diagnostic application of monoclonal antibodies specific to rabies virus

Objective：Rabies is invariably a fatal encephalomyelitis that is considered to be a serious public health problem.It is necessary to develop standard rabies virus diagnostic tools,especially for diagnosing the strains prevalent in China.Methods：Monoclonal antibodies（MAbs）specific to rabies virus were produced and characterized by enzyme linked immunosorbent assay（ELISA）,isotyping,affinity assay,immunofluorescence assay（IFA）,and immunocytochemistry.The MAb,whose affinity was higher for antigen,was used to establish an antigen captureELISA（AC-ELISA）detection system and test the efficiency by using clinical samples.Results：The heavy chain subclasses of two MAbs were all determined to be IgG2a.The 3C7 MAb showed stronger reactivity with rabies virus protein than the 2C5 MAb in an ELISA analysis,whereas the 3C7 MAb showed the highest affinity for antigen.IFA and immunocytochemistry results also indicated that the two MAbs could recognize rabies virus protein in its native form in cell samples.Data obtained using clinical samples showed that rabies virus could be detected by AC-ELISA detection system using the 3C7 MAb.Conclusion：It was potentially useful for the further development of highly sensitive,easily handled,and relatively rapid detection kits/tools for rabies surveillance in those areas where rabies is endemic,especially in China.

Isolated anti-HBc is an independent risk factor for tumor recurrence in intrahepatic cholangiocarcinoma after curative resection

Background:Intrahepatic cholangiocarcinoma(ICC)is a poorly understood and aggressive malignancy with increasing incidence and mortality.Hepatitis B virus(HBV)infection is recognized as one of the important risk factors of ICC.There are few reports focusing on whether isolated antibody to hepatitis B core antigen(isolated anti-HBc,IAHBc)have prognostic role in ICC,while positive hepatitis B surface antigen(HBsAg)has been reported to be associated with the prognosis of ICC.The aim of this study was to investigate the prognostic value of IAHBc in ICC patients after curative resection,in order to identify those who have the high risk of ICC recurrence in the early stage.Methods:We divided 209 ICC patients who underwent curative resection into 4 groups:groupⅠ(n=40),HBsAg(-)/antibody to hepatitis B surface antigen(anti-HBs)(-)/anti-HBc(+);groupⅡ(n=70),HBsAg(+)/anti-HBc(-);groupⅢ(n=55),HBsAg(-)/anti-HBs(+)/anti-HBc(+);and groupⅣ(n=44),HBsAg(-)/anti-HBc(-).We compared the recurrence-free survival(RFS)and overall survival(OS)among these four groups.Results:The median follow-up time was 16.93 months(range 1-34.6 months).The 1-and 2-year RFS and OS rates were 60%and 42%,and 78%and 63%respectively in all patients.Compared to the whole non-IAHBc patients(groupⅡ+groupⅢ+groupⅣ),IAHBc patients(groupⅠ)showed significantly lower RFS at 1 year(39.8%vs.64.4%,P=0.001)and 2 years(20.7%vs.46.7%,P=0.001).When compared to other three individual groups,IAHBc patients(groupⅠ)also had the lowest RFS.We did not find significant difference in OS among the four groups.Further multivariate analysis revealed that IAHBc was an independent risk factor of RFS.Conclusions:IAHBc is an independent poor prognostic factor for tumor recurrence in ICC patients after curative resection.

ANALYSIS ON EPITOPES OF IGM WITH MONOCLONAL ANTI-ISOTYPIC AND ANTI-IDIOTYPIC ANTIBODIES AGAINST IgM FROM B-CLL

A double antibodies additivity ELISA test was employed to identify the epltopes which can be recognized by monoclonal antibodies (McAbs) against IgM from B chronic lymphocyte leukemia (B-CLL). The computer grouping programme analysis showed that 4 and- isotypic MaAbs could be divided into two groups and 10 anti- idiotype McAbs could be divided into four groups. The result was consistent with that of the indirect sandwich ELISA and inhibition ELISA test. It suggested that there were at least 6 distinct IgM epitopes which can react specifically with 14 McAbs. Our study indicated that the combination of the additivity ELISA test and the computer grouping programme analysis is of help in studying the relationship of the structure and function of antigen.

Innovative immunosuppression in kidney transplantation:A challenge for unmet needs

Due to the optimal results obtained in kidney transplantation and to the lack of interest of the industries,new innovative drugs in kidney transplantation are difficult to be encountered.The best strategy to find the new drugs recently developed or under development is to search in the sections of kidney transplantation still not completely covered by the drugs on the market.These unmet needs are the prevention of delayed graft function(DGF),the protection of the graft over the long time and the desensitization of preformed anti human leukocyte antigen antibodies and the treatment of the acute antibody-mediated rejection.These needs are particularly relevant due to the expansion of some kind of kidney transplantation as transplantation from non-heart beating donor and in the case of antibody-incompatible grafts.The first are particularly exposed to DGF,the latter need a safe desensitization and a safe treatments of the antibody mediated rejections that often occur.Particular caution is needed in treating these drugs.First,they are described in very recent studies and the follow-up of their effect is of course rather short.Second,some of these drugs are still in an early phase of study,even if in well-conducted randomized controlled trials.Particular caution and a careful check need to be used in trials launched 2 or 3 years ago.Indeed,is always necessary to verify whether the study is still going on or whether and why the study itself was abandoned.

Study of antigen and antibody reaction in electrochemical reactions with ellipsometric spectroscopy

IN the study of antigen and antibody reaction with ellipsometric spectroscopy, most researchers calculated the thickness of antibody film, absorbance and film constant by mathematic models.But by using simple mathematic models, it is very hard to describe accurately the real state of the system. Huang and Ord proposed a new physical measurement (optical tracking rate,Vop), indicating the total change of △, Ψ in study of oxidation and reduction reaction of the iron electrode in alkaline solution. Many experimental results showed that the spectral peaks in Vop～t figure correspond to the turning points on the polarization curve. This work

Evaluate the prevalence and trend of hepatitis B and hepatitis C in Nahavand: west of Iran, 2013–2017

Viral hepatitis is a global threat to public health and one of the leading causes of death worldwide.Often,acute viral cases in children and adults are associated with viral hepatitis A,B,C,D and E,or co-infection with two types of hepatitis.Infection with these viruses is a global health problem and continuous efforts are in place to identify infected people through targeted screening,preventing new infections through vaccination,monitoring and treating people at risk for complications of all types of hepatitis.The aim of this study was to determine the evaluate the prevalence and trends of hepatitis B and C infection in the Nahavand city during 5 consecutive years(2013–2017).The total number of patients with hepatitis B and C was 141 persons from March 2013 to March 2017,of these,101 had hepatitis B,and 40 had hepatitis C.The prevalence of hepatitis B and C was higher in men than women.The percentage frequency hepatitis B in the city in the last five years was 0.05 percent.11 cases(10.89%)pregnant women and Six cases(5.9%)receiving blood(blood transfusions)in Hepatitis B was observed.the prevalence of hepatitis C was 0.2%at the end of 2017.The study on the cause of hepatitis C in Nahavand has shown that 21(52.5%)of the total of 40 people were infected with addiction.The interesting point in this report is that according to reports from viral hepatitis testing questionnaires,24 of 101 people with type B hepatitis have 23.7%of people with a history of complete vaccination of hepatitis B and one person(0.9%)had incomplete vaccination.A significant relationship was found between the level of education and the prevalence of hepatitis(P=0.005).

The positive influence the Onchocerciasis Elimination Program for the Americas has had on Africa programs

A recent article Is onchocerciasis elimination in Africa feasible by 2025:a perspective based on lessons learnt from the African control programmesH in Infectious Diseases of Poverty claimed that undue influence on African programs by concepts developed by the Onchocerciasis Elimination Program of the Americas(OEPA)is detrimental to stopping mass drug administration(MDA)in Africa.This claim is made despite a record year for MDA stoppage in four African countries of>3.5 million treatments in 2018,far exceeding any past OEPA or African Program for Onchocerciasis Control(APOC)stop MDA success.