Blockade of Rho-associated kinase prevents inhibition of axon regeneration of peripheral nerves induced by anti-ganglioside antibodies

Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon regeneration.Cross-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon regeneration.These effects involve the activation of the small GTPase Rho A/ROCK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so far.The aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROCK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated fibers.Our results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of Y-27632.Treatment with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous sensitivity.In contrast,the same dose showed toxic effects on the regeneration of myelinated fibers.Interestingly,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only Y-27632.Overall,these findings confirm the in vivo participation of Rho A/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal antibody.Our findings open the possibility of therapeutic pharmacological intervention targeting Rho A/Rock pathway in immune neuropathies associated with the presence of anti-ganglioside antibodies and delayed or incomplete clinical recovery after injury in the peripheral nervous system.

Atypical Guillain-Barrésyndrome with positive anti-sulfatide,anti-GT1b,and anti-GT1a antibodies:A case report

BACKGROUND The role of diverse antibodies in mediating peripheral nerve injury in Guillain-Barrésyndrome(GBS)is becoming clearer,but positivity for multiple antibodies in one case is uncommon.To our knowledge,this is the first case involving GBS with positive anti-sulfatide,anti-GT1a,and anti-GT1b antibodies.CASE SUMMARY A 20-year-old female patient was admitted to the hospital due to weakness of limbs for 5 d,and deterioration of the weakness and muscle aches for 1 d.The patient's limbs were weak,but the tendon reflexes in the part of the limbs were normal.There was no comorbid peripheral nociception or deep sensory dysfunction.She was diagnosed with GBS and was discharged after receiving intravenous human immunoglobulin pulse therapy.CONCLUSION In this article,the clinical manifestations,neurophysiological examination,and auxiliary examination findings of a GBS patient positive for multiple antibodies were analyzed to improve the identification of the disease by clinical physicians at an early stage.

Miller fisher syndrome with positive anti-GQ1b/GT1a antibodies associated with COVID-19 infection:A case report

BACKGROUND Miller fisher syndrome(MFS)is a variant of Guillain-Barrésyndrome,an acute immune-mediated peripheral neuropathy that is often secondary to viral infections.Anti-ganglioside antibodies play crucial roles in the development of MFS.The positive rate of ganglioside antibodies is exceptionally high in MFS patients,particularly for anti-GQ1b antibodies.However,the presence of other ganglioside antibodies does not exclude MFS.CASE SUMMARY We present a 56-year-old female patient who suddenly developed right blepharoptosis and progressively worsening vision in both eyes.There were flu symptoms prior to onset,and a coronavirus disease 2019 test was positive.On physical examination,the patient exhibited bilateral extraocular muscle paralysis,weakened reflexes in both limbs,and impaired coordination.The cerebrospinal fluid examination results showed no obvious abnormalities.Bilateral peroneal nerve F-waves were not extracted.Serum anti-GD1b IgG and anti-GT1a IgG antibodies were positive.The patient received intravenous methylprednisolone(1000 mg/day),with the dosage gradually decreased.Additionally,intravenous high-dose immunoglobulin treatment was administered for 5 days(0.4 g/kg/day)from day 2 to day 6 of hospitalization.The patient’s symptoms improved after treatment with immunoglobulins and hormones.CONCLUSION Positive ganglioside antibodies may be used as supporting evidence for the diagnosis;however,the diagnosis of MFS is more reliant on clinical symptoms.

Human leukocyte antigen and donor-specific antibodies in liver transplantation

In this article,we comment on an article published in a recent issue of the World Journal of Gastroenterology.We specifically focus on the roles of human leukocyte antigen(HLA)and donor-specific antibodies(DSAs)in pediatric liver transpl-antation(LT),as well as the relationship between immune rejection after LT and DSA.Currently,LT remains the standard of care for pediatric patients with end-stage liver disease or severe acute liver failure.However,acute and chronic re-jection continues to be a significant cause of graft dysfunction and loss.HLA mismatch significantly reduces graft survival and increases the risk of acute rejection.Among them,D→R one-way mismatch at three loci was significantly related to graft-versus-host disease incidence after LT.The adverse impact of HLA-DSAs on LT recipients is already established.Therefore,the evaluation of HLA and DSA is crucial in pediatric LT.

New glucocerebrosidase antibodies can advance research in the field of neurodegenerative disorders

In medical research,there are times when the introduction of a new tool can launch scientific discovery in new directions.While antibody development may be considered mundane,in the field of glucocerebrosidase(GCase)research,the dearth of validated antibodies for different applications has impeded progress in studies of disease pathogenesis and therapeutic development.The recent introduction of new,rigorously evaluated antibodies can now propel research into the link between glucocerebrosidase and Parkinson’s disease(PD)as well as aspects of the pathobiology of Gaucher disease(Jong et al.,2024).

Expanding role of antibodies in kidney transplantation

The role of antibodies in kidney transplant(KT)has evolved significantly over the past few decades.This role of antibodies in KT is multifaceted,encompassing both the challenges they pose in terms of antibody-mediated rejection(AMR)and the opportunities for improving transplant outcomes through better detection,prevention,and treatment strategies.As our understanding of the immunological mechanisms continues to evolve,so too will the approaches to managing and harnessing the power of antibodies in KT,ultimately leading to improved patient and graft survival.This narrative review explores the multifaceted roles of antibodies in KT,including their involvement in rejection mechanisms,advancements in desensitization protocols,AMR treatments,and their potential role in monitoring and improving graft survival.

Serological surveillance for SARS-CoV-2 antibodies among students,faculty and staff within a large university system during the pandemic

BACKGROUND At the end of December 2019,the world faced severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),which led to the outbreak of coronavirus disease 2019(COVID-19),associated with respiratory issues.This virus has shown significant challenges,especially for senior citizens,patients with other underlying illnesses,or those with a sedentary lifestyle.Serological tests conducted early on have helped identify how the virus is transmitted and how to curb its spread.The study hypothesis was that the rapid serological test for SARS-CoV-2 antibodies could indicate the immunoreactive profile during the COVID-19 pandemic in a university population.AIM To conduct active surveillance for serological expression of anti-SARS-CoV-2 antibodies in individuals within a university setting during the COVID-19 pandemic.METHODS This sectional study by convenience sampling was conducted in a large university in Niteroi-RJ,Brazil,from March 2021 to July 2021.The study population consisted of students,faculty,and administrative staff employed by the university.A total of 3433 faculty members,60703 students,and 3812 administrative staff were invited to participate.Data were gathered through rapid serological tests to detect immunoglobulin(Ig)M and IgG against SARS-CoV-2.Theχ²or Fisher's exact test was used to conduct statistical analysis.A 0.20 significance level was adopted for variable selection in a multiple logistic regression model to evaluate associations.RESULTS A total of 1648 individuals were enrolled in the study.The proportion of COVID-19 positivity was 164/1648(9.8%).The adjusted logistic model indicate a positive association between the expression of IgM or IgG and age[odds ratio(OR)=1.16,95%CI:1.02-1.31](P<0.0024),individuals who had been in contact with a COVID-19-positive case(OR=3.49,95%CI:2.34-5.37)(P<0.001),those who had received the COVID-19 vaccine(OR=2.33,95%CI:1.61-3.35)(P<0.001)and social isolation(OR=0.59,95%CI:0.41-0.84)(P<0.004).The likelihood of showing a positive result increased by 16%with every ten-year increment.Conversely,adherence to social distancing measures decreased the likelihood by 41%.CONCLUSION These findings evidenced that the population became more exposed to the virus as individuals discontinued social distancing practices,thereby increasing the risk of infection for themselves.

Automatic Evaluation of Test Strips for Anti-Ganglioside Antibodies in Patients with Guillain-BarréSyndrome Using EUROLineScan Software

Campylobacter jejuni infection has been implicated in the pathogenesis of Guillain-Barré syndrome (GBS) due to production of humoral immune response against neural antigens. A case-control study was performed in a tertiary care teaching hospital for the estimation of anti-ganglioside antibodies in GBS patients and their controls. Blood samples were collected from 59 GBS cases, 58 neurological controls (NC) and 60 non-neurological control (NNC) patients for automatic estimation of IgG and IgM antibodies to seven gangliosides using EUROLineScan software. Antibodies of IgG class for GM1 were highly significant in GBS (p = 0.000) and NC (p = 0.031) compared to NNC. However GBS group was not significant (p = 0.413) compared to NC. For GM2 ganglioside, GBS and NC groups were significant (p = 0.000) compared to NNC, but GBS group was not significant (p = 0.999) compared to NC. For GM3 ganglioside, GBS and NC groups were significant (p = 0.000) compared to NNC;but GBS group was insignificant (p = 0.858) compared to NC with similar trend for all other ganglioside antibodies. When IgM class of antibodies was evaluated for GM1, GBS group was not significant (p = 0.604) whereas NC group was significant (p = 0.000) compared to NNC. GBS group was not significant compared to NC (p = 0.011). The trend was the same for GM2 antibodies. For GM3, GBS group was significant (p = 0.010) and NC was near significant (p = 0.055) compared to NNC. However GBS group was not significant (p = 0.808) compared to NC. No groups were significant (p > 0.05) in relation to the remaining gangliosides except for GQ1b where GBS group (p = 0.001) and NC group were significant (p = 0.000) compared to NNC. GBS group was also significant (p = 0.001) compared to NC and NNC. Anti-gangliosides antibodies were present in highly significant levels in the GBS group, though they were also present in the non-paralytic neurological control patients compared to the non-neurological control group.

Organizing Pneumonia in A Patient Double-Positive for ANCA and Anti-GBM Antibodies:A Case Report

Both anti-glomerular basement membrane(GBM)disease and the anti-neutrophil cytoplasmic antibody(ANCA)-associated vasculitis(AAV)are common causes of pulmonary-renal syndrome.Organizing pneumonia(OP),a special pattern of interstitial lung disease,is extremely rare either in AAV or anti-GBM disease.We report an old woman presented with OP on a background of co-presentation with both ANCA and anti-GBM antibodies.

Role of C-Peptide in Relation to Levels of Anti-GAD and Islet Cell Antibodies in Characterizing Types of Diabetes in the Young, in Eastern India

Background: Measuring fasting C-peptide (FCP) and antibodies against Glutamic acid decarboxylase (GADA) and Islet cell antibodies (ICA) are not so commonly explored in children and young adults. Objectives: To assess the levels of FCP, GADA and ICA in subjects below the age of 25 years with DM and compare their levels to differentiate between Autoimmune and Non-Autoimmune Type 1 DM. Methodology: Blood samples of 93 subjects diagnosed with DM, reporting to the tertiary care hospital, were analysed for ICA, GADA and FCP. Receiver operating characteristics (ROC) curves were analysed to check the ability of autoimmune markers, BMI and C-peptide to differentiate between Autoimmune (Ai) and Non-Autoimmune (NonAi) diabetes. Results: 30/93 (32.2%) were positive for anti-GAD ab and/or ICA and categorised as Autoimmune (Ai), the most common antibody being, anti-GAD ab (80%) in them. The level of FCP among Ai compared to NonAi, was significantly low (p 20.75 nmol/l) as a very dependable test for diagnosing Ai, Type 1 DM, in children and young adults. Its sensitivity and specificity are in the range of 86.2% and 96.8% respectively. Low level of C-peptide (Conclusion: This study revealed predominant positivity for anti-GAD ab (80%) among Ai+ patients. ROC analysis shows GADA above 20.75 nmol/l and Fasting C-peptide < 0.36 nmol/l as a good indicator for diagnosing Ai in children and young adults.

Role of GM3 ganglioside in the pathology of some progressive human diseases and prognostic importance of serum anti-GM3 antibodies

Glycosphingolipids(gangliosides)have been characterized as important biological molecules with a key role as regulators in many physiological processes on cellular,tissue,organ,and organism levels.The deviations in their normal amounts,production,and metabolism are very often related to the development of many multi-factor socially important diseases.GM3 ganglioside,as a small molecule,plays important roles in the cascade regulatory pathways in the pathology of many disorders like neurodegenerative diseases,autoimmune diseases,inflammation,diabetes,malignant transformation,and others.Ganglioside GM3 and its derivatives are membrane-bound glycosphingolipids composed of an oligosaccharide head structure containing one sialic acid residue.These molecules transduce signals involved in cell surface events,including the phosphorylation of transmembrane receptors.This ganglioside is the most widely distributed among tissues,and it serves as a precursor for most of the more complex ganglioside species.GM3 inhibits the function of fibroblast growth factor receptor,and cell growth is regulated by GM3-enriched microdomain.GM3 is thought to inhibit immunologic functions,such as the proliferation and production of cytokines by T cells.On the other hand,the anti-ganglioside antibodies(AGAs)are important in many acquired demyelinating immunemediated neuropathies,like Multiple sclerosis(MS),Guillain–Barrésyndrome(GBS)and its variation,Miller–Fisher syndrome(MFS)and could be suggested as important diagnostic and prognostic markers about the describe diseases and their etiology.We show that the complexes of anti-ganglioside antibodies to GM3(detected by ELISA)may be useful diagnostic and prognostic tool markers for autoimmune diseases,neurodegenerative disorders,malignancy,diabetes,and inflammation.Our pilot studies suggest increased serum IgG anti-GM3 antibodies titers in patients with secondary progressive MS(SPMS),throat cancer,elder people with diabetes(89–96 years),old Lewis rats(30–33 months),and in the serum of subjected on lead intoxication BALB/c mice treated by salinomycin.We observed no changes in the titers in healthy elder people(89–96 years),in 70-year-old woman on dialysis,in relapsing-remitting MS(RRMS)patients on long-term treatment with Glatiramer acetate,Laquinimod,and Interferons,as well as in 18–22 months old Wistar rats and subjected on lead intoxication BALB/c mice treated by monensin and dimercaptosuccinic acid(DMSA).Considerable decrease of serum GM3 in early MS correlate with early damage and severe destruction of the blood–brain barrier,which provides impetus to initiate early therapy.

Periodontitis and Inflammation: Plasma High Titer Naturally Occurring Anti-Glucan Antibodies Form Immune Complex with Streptococcus mutans Antigen

Atheromatous plaques usually contain antigens of the periodontitis-causing bacteria Streptococcus mutans though molecular mechanism of this incorporation remains unknown. Since vascular adhesion and inflammatory potential of Immune Complexes (IC) are known we investigated the naturally occurring plasma antibodies that recognize major antigens from S. mutans. S. mutans-binding plasma proteins (SMBP) prepared by affinity chromatography on a column of heat-killed S. mutans could recognize α- and β-linked glucose in dextran and yeast respectively but not galactose in glycoproteins. SMBP contained only three proteins, each corresponding in electrophoretic mobility to standard plasma IgG, IgA or IgM. The major positively and negatively charged protein antigens (PSMAg and NSMAg) isolated from S. mutans by electrophoresis and ion exchange chromatography respectively were recognized sugar-reversibly by the anti-β-glucan antibody (ABG) and though less avidly, by the dextran-binding immunoglobulin (DIg) in normal plasma. NSMAg addition resulted in near doubling of IC-bound immunoglobulins in immunoglobulin-rich fraction of plasma. IC isolated from above fraction after NSMAg addition had substantially more IgA and IgM content than total plasma immunoglobulins. IC formation by NSMAg was significantly inhibited by ABG- and DIg-specific sugars or by selective withdrawal of ABG or DIg from plasma. ABG and DIg being relatively high titer plasma antibodies IC formation with them suggested a possible route for vascular adhesion and damage by S. mutans and its antigens. Further, high IgA content of these ICs indicated their susceptibility to tissue uptake through cell surface galectin-1 for which IgA is the lone immunoglobulin ligand.

CYTOTOXICITY OF INDIRECT IMMUNOTOXIN MEDIATED BY ANTI-GASTRIC CANCER MONOCLONAL ANTIBODIES ON TUMOR CELLS

In the present study, an indirect assay was employed to investigate 5 anti-gastric cancer monoclonal antibodies for their cytotoxic potential as ricin A chain-containing immunotoxins. The tumor cell, were treated with dilutions of tested antibody followed by ricin A chain coupled to goat anti-mouse immunoglobulin. The cytotoxic effect was determined with tetrazolium colorimetric assay. The results showed that among the 5 antibodies chosen, MGb2 and MG7 could be well used for preparation of effective A chain immunotoxins.

Autoantibodies related to ataxia and other central nervous system manifestations of gluten enteropathy

Gluten ataxia and other central nervous system disorders could be linked to gluten enteropathy and related autoantibodies.In this narrative review,we focus on the various neuro-logical manifestations in patients with gluten sensitivity/celiac disease,immunological and autoimmune mechanisms of ataxia in connection to gluten sensitivity and the autoantibodies that could be used as a biomarker for diagnosing and following.We focused on the anti-gliadin antibodies,antibodies to different isoforms of tissue transglutaminase(TG)(anti-TG2,3,and 6 antibodies),anti-glycine receptor antibodies,anti-glutamine acid decarboxylase antibodies,anti-deamidated gliadin peptides antibodies,etc.Most studies found a higher prevalence of these antibodies in patients with gluten sensitivity and neurological dysfunction,presented as different neurological disorders.We also discuss the role of a gluten-free diet on the clinical improvement of patients and also on imaging of these disorders.

A nanobody-based blocking enzyme-linked immunosorbent assay for detecting antibodies against pseudorabies virus glycoprotein E

Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA)has been used to distinguish gE-deleted vaccine-immunized pigs from wild-type virus-infected pigs to eradicate PR in some countries.Nanobody has the advantages of small size and easy genetic engineering and has been a promising diagnostic reagent.However,there were few reports about developing nanobody-based ELISA for detecting anti-PRV-gE antibodies.In the present study,the recombinant PRV-gE was expressed with a bacterial system and used to immunize the Bactrian camel.Then,two nanobodies against PRV-gE were screened from the immunized camel by phage display technique.Subsequently,two nanobody-HRP fusion proteins were expressed with HEK293T cells.The PRV-gE-Nb36-HRP fusion protein was selected as the probe for developing the blocking ELISA(bELISA)to detect anti-PRV-gE antibodies.Through optimizing the conditions of bELISA,the amount of coated antigen was 200 ng per well,and dilutions of the fusion protein and tested pig sera were separately 1:320 and 1:5.The cut-off value of bELISA was 24.20%,and the sensitivity and specificity were 96.43 and 92.63%,respectively.By detecting 233 clinical pig sera with the developed bELISA and a commercial kit,the results showed that the coincidence rate of two assays was 93.99%.Additionallly,epitope mapping showed that PRV-gE-Nb36 recognized a conserved conformational epitope in different reference PRV strains.Simple,great stability and low-cost nanobody-based bELISA for detecting anti-PRV-gE antibodies were developed.The bELISA could be used for monitoring and eradicating PR.

Antibodies Targeting a Conserved Surface Polysaccharide Are Protective Against a Wide Range of Microbial Pathogens Producing β-1-6-Linked Poly-N-Acetylglucosamine(PNAG)

The b-1-6-linked poly-N-acetylglucosamine(PNAG)polymer is a conserved surface polysaccharide produced by many bacteria,fungi,and protozoan(and even filarial)parasites.This wide-ranging expression makes PNAG an attractive target for vaccine development,as it potentially encompasses a broad range of microorganisms.Significant progress has been made in discovering important properties of the biology of PNAG expression in recent years.The molecular characterization and regulation of operons for the production of PNAG biosynthetic proteins and enzymes have been studied in many bacteria.In addition,the physiological function of PNAG has been further elucidated.PNAG-based vaccines and PNAG-targeting antibodies have shown great efficacy in preclinical research.Furthermore,clinical tests for both vaccines and antibodies have been carried out in humans and economically important animals,and the results are promising.Although it is not destined to be a smooth road,we are optimistic about new vaccines and immunotherapeutics targeting PNAG becoming validated and eventually licensed for clinical use against multiple infectious agents.

Establishment of an indirect immunofluorescence assay for the detection of African swine fever virus antibodies

African swine fever(ASF)continues to cause enormous economic loss to the global pig industry.Since there is no safe and effective vaccine,accurate and timely diagnosis of ASF is essential to implement control measures.Indirect immunofluorescence assay(IFA)is a gold standard serological method recommended by the World Organization for Animal Health(WOAH).In this study,we used primary fetal kidney cells to establish a wild boar cell line(BK2258)that supported the efficient replication of ASF virus(ASFV)SD/DY-I/21 and showed visible cytopathic effect(CPE).Moreover,using BK2258,we established a sensitive and specific IFA for ASFV antibody detection.To standardize and evaluate the performance of this assay,we used serum samples from pigs infected with the low virulent genotype I SD/DY-I/21 and genotype II HLJ/HRB1/20,and immunized with the vaccine candidate HLJ/18-7GD,field samples,and negative serum samples.The IFA reacted with the ASFV-positive sera and displayed bright fluorescence foci.There was no non-specific green fluorescence due to cellular senescence or other cell damage-causing factors.Compared to a commercial indirect enzyme-linked immunosorbent assay(iELISA),ASFV antibodies were detected 1–4 days earlier using our IFA.The detection limits of the IFA and iELISA for the same ASFV-antibody positive serum samples were 1:25,600 and 1:6,400,respectively,indicating that the IFA is more sensitive than iELISA.The newly established IFA was highly specific and did not cross-react with sera positive for six other important porcine pathogens(i.e.,Classical swine fever virus(CSFV),Porcine reproductive and respiratory syndrome virus(PRRSV),Porcme circovirus type 2(PCV2),Pseudorabies virus(PRV),Foot-and-Mouth disease virus type O(FMDV/O),and Porcine epidemic diarrhea virus(PEDV)).This study thus provides a sensitive,specific,and reliable detection method that is suitable for the serological diagnosis of ASF.

Allogenic Stem Cell Transplantation and COVID-19 Antibodies: Mechanistic Insights and Recipient Concerns

Collecting umbilical cord stem cells is widely practiced due to its numerous benefits. Over the past decade, umbilical cord stem cells (UCSCs) have shown effectiveness in treating various conditions, such as bone pathologies, neuropsychiatry disorders, hereditary diseases, and metabolic disorders. However, factors like immunization affect the quantity and quality of cord harvesting. Studies suggest that antibodies from the mother pass through the umbilical cord to protect the infant against infections. Cleaning the umbilical cord before stem cell extraction is crucial to maintain sterility and cell integrity. Vaccinating a female donor, including for COVID-19, typically does not directly affect the stem cells. Although vaccines aim to trigger an immunological response, they generally do not affect the donor’s stem cells.

Evaluation of the Concentration of Anti-Spermatozoa Antibodies in Seminal Plasma of Normozoosperms and Azoosperms of Patients at the Pasteur Institute of Cote d’Ivoire

Under normal circumstances, spermatozoa are protected from the immune system by the blood-testis barrier. The breakdown of this barrier is the origin of the synthesis of antisperm antibodies (ASA). The presence of sperm agglutinates in semen is characteristic of ASA. But is the presence of agglutinates in semen necessarily linked to the level of ASA in semen? The objective of this study was to assess the concentration of anti-sperm antibodies (ASA) in normozoosperms and infertile men with azoospermia. The biological material consisted of samples of human sperms: 30 samples with azoospermia and 32 with normozoospermia. The ASA assay was performed in seminal plasma using the DRG® Sperm Antibody ELISA (seminal plasma) kit (EIA-4249). The reading was carried out using a microplate reader at 450 nm. Data analysis was performed using Graph Pad Prism 7 software. The results obtained showed that the difference in ASA concentration between these two categories of sperm was not significant, with an average ASA level of 31.54 ± 2.45 U/mL in azoospermic ejaculate and 27.63 ± 1.51 U/mL in normozoosperms. Statistical analysis showed higher ASA concentrations in azoosperms with 6.67% of these declared positive. The ASA positivity rate made it possible to distinguish secretory azoospermias from obstructive ones. Also, the presence of ASA is not necessarily linked to the presence of agglutinates in the semen.

Human leukocyte antigen compatibility and incidence of donorspecific antibodies in pediatric liver transplant recipients

BACKGROUND Antibody-mediated rejection following liver transplantation(LT)has been increasingly recognized,particularly with respect to the emergence of de novo donor-specific antibodies(DSAs)and their impact on graft longevity.While substantial evidence for adult populations exists,research focusing on pediatric LT outcomes remains limited.AIM To investigate the prevalence of human leukocyte antigen(HLA)mismatches and DSA and evaluate their association with rejection episodes after pediatric LT.METHODS A cohort of pediatric LT recipients underwent HLA testing at Santa Casa de Porto Alegre,Brazil,between December 2013 and December 2023.Only patients who survived for>30 days after LT with at least one DSA analysis were included.DSA classes I and II and cross-matches were analyzed.The presence of de novo DSA(dnDSA)was evaluated at least 3 months after LT using the Luminex®single antigen bead method,with a positive reaction threshold set at 1000 MFI.Rejection episodes were confirmed by liver biopsy.RESULTS Overall,67 transplanted children were analyzed;61 received grafts from living donors,85%of whom were related to recipients.Pre-transplant DSA(class I or II)was detected in 28.3%of patients,and dnDSA was detected in 48.4%.The median time to DSA detection after LT was 19.7[interquartile range(IQR):4.3-35.6]months.Biopsyproven rejection occurred in 13 patients at follow-up,with C4d positivity observed in 5/13 Liver biopsies.The median time to rejection was 7.8(IQR:5.7-12.8)months.The presence of dnDSA was significantly associated with rejection(36%vs 3%,P<0.001).The rejection-free survival rates at 12 and 24 months were 76%vs 100%and 58%vs 95%for patients with dnDSA anti-DQ vs those without,respectively.CONCLUSION Our findings highlight the importance of incorporating DSA assessment into pre-and post-transplantation protocols for pediatric LT recipients.Future implications may include immunosuppression minimization strategies based on this analysis in pediatric LT recipients.