Zika virus antibody-positivity among symptomatic/asymptomatic pregnant women in the Aseer region displays pre-exposure to dengue viruses

@#Antibody cross-reactivity among flaviviruses is a major limitation in understanding the prevalence without vector control measures. In this study, we investigated the presence of Zika virus (ZIKV)-specific antibodies and the significance of their cross-reactivity with other flaviviruses, which could affect the serological specificity in both symptomatic and asymptomatic pregnant women. Among the results obtained from 217 serum samples tested for ZIKV-specific IgM and IgG, no specific predictions regarding seropositivity or exposure due to extensive cross-reactivity with dengue virus (DENV) serology could be made. Clear-cut positivity was observed in 1.8% (n = 4) and 1.0% (n = 2) for ZIKV IgM and IgG, respectively. The same samples assessed for DENV showed 1.3% (n = 3) seropositivity each for IgM and IgG levels. None of the samples were positive for ZIKV and DENV IgM or IgG. However, one sample (0.4%) tested positive for ZIKV and DENV IgM. No significant correlation was observed between DENV IgM and IgG when comparing the overlapped serotiters. On the other hand, the ZIKV IgG-positive sample showed higher serotiters for DENV IgG, indicating cross-reactivity with ZIKV but without statistical significance. Therefore, screening for the incidence of ZIKV becomes particularly challenging in a population where the presence or pre-exposure to DENV is observed. Our observations further suggest that unless flavivirus prevalence is properly addressed, determining the prevalence of ZIKV antibodies, which may be confounded with other uninvestigated flaviviruses, will be complicated.

Immunogenicity of Whole / 生物医学与环境科学（英文）

Objectives@#To evaluate the immunogenicity of @*Methods@#Protein extracts from @*Results@#Immunization with @*Conclusion@#This is the advanced study to investigate the immunogenicity of

Cross immune reaction between Mycobacteria smegmatis and Mycobacteria tuberculosis / 中华微生物学和免疫学杂志

Objective To identify the cross-reactive antigens shared by Mycobacteria smegmatis(MS) and Mycobacteria tuberculosis(MTB) and to analyze their antigenicity.Methods Bacterial antigens were extracted from strains of MS and MTB by ultrasonication.Western blot assay was performed to analyze common antigens that reacted with both of the antiserum samples against MS and MTB.The extracted bacterial antigens were mixed with incomplete Freund′s adjuvant and then were injected into muscles of mice.Cytokines secreted by murine spleen lymphocytes following stimulation with various antigens of MS and MTB were determined by ELISPOT and flow cytometry on the 7th day.IgG levels in serum samples were detected by ELISA 7 days after injection.Results There were cross-reactive antigens shared by MS and MTB.Potent humoral immune responses and cellular immunity against both MS and MTB could be induced by those cross-reactive antigens after sensitization the mice by either MS or MTB antigens.Cytokines of IL-2 and IFN-γ in CD4+ and CD8+T cells of mice stimulated with MS or MTB antigens were significantly increased as compared with those of non-sensitization group and those of Brucella antigens stimulation group.ConclusionCross-reactive antigens shared by MS and MTS can effectively promote specific immune reactions to the infection of MTB, which provides a scientific basis for the development of tuberculosis vaccines.

Involvement of cross-reactive carbohydrate determinants-specific IgE in pollen allergy testing

BACKGROUND: Specific IgE antibodies against the low-molecular-weight carbohydrate antigen that does not bridge IgE molecules on mast cells are not associated with clinical symptoms. Cross reactivity can be determined in allergen-specific IgE detection assays when the carbohydrate structures between pollen allergens and plant derived food allergens are similar; in such cases, false positive results for grain or legume allergens can be reported for pollen allergic patients who are not sensitized to those allergens. This phenomenon arises owing to the presence of cross-reactive carbohydrate determinants (CCDs). OBJECTIVE: This study aimed to assess the impact of CCD interference on the results for pollen allergen-specific IgE antibodies in the general adult population and to perform CCD inhibition tests evaluating the involvement of CCD on samples positive to pollen allergens. METHODS: Serum samples from 322 subjects were tested for IgE antibodies to pollens and CCD. The research subjects were given questionnaires about pollen allergic symptoms to help assess the presence of allergies. Allergen IgE antibodies for Japanese cedar, Japanese cypress, orchard grass, ragweed, MUXF, bromelain, horseradish peroxidase (HRP), and ascorbate oxidase (ASOD) were analyzed. RESULTS: It was observed that among individuals who tested positive to any of the pollen allergens, the positive ratio of CCD-specific IgE antibody was the highest for HRP (13.5%–50.0%). The results from the inhibition tests revealed that CCD was marginally present. Although IgE antibodies for cedar pollen did not react with CCD, IgE antibodies for Japanese cypress, orchard grass, and ragweed might be detected by the presence of CCD. CONCLUSION: The results of the inhibition tests revealed the obvious presence of CCD suggesting its involvement. Considering these findings, careful evaluation of patient IgE results should be performed for Japanese cypress, orchard grass, and ragweed.

Dengue hemorrhagic fever in a Japanese traveler who had preexisting Japanese encephalitis virus antibody

A patient, an adultJapanese traveler who had just returned from Thailand, had developed denguehemorrhagic fever (DHF). A primary infection of dengue virus (DENV) wasconfirmed, in particular, DENV serotype 2 (DENV-2) via the detection of the virusgenome, a significant increase in its specific neutralizing antibody and the isolationof DENV-2. DHF is often observed following a secondary infection from another serotypeof dengue virus, particularly in children, but this case was a primaryinfection of DENV. Japan is a non-endemic country of dengue disease. Instead,only Japanese encephalitis (JE) is known to be an endemic flavivirus family. Inthis study, IgG antibody against Japanese encephalitis virus (JEV) was detected.JEV belongs to the family of dengue virus and prevails in Japan, particularly inKyushu. Among many risk factors for the occurrence of DHF, a plausiblecandidate could be a cross-reactive antibody-dependent enhancement (ADE)mechanism by JEV antibody. This indicates that most Japanese travelers, wholive in non-endemic areas of dengue, particularly in Kyushu, should payattention to the occurrence of DHF.

Dengue Hemorrhagic Fever in a Japanese Traveler with Pre-existing Japanese Encephalitis Virus Antibody

An adult Japanese man who had just returned from Thailand developed dengue hemorrhagic fever (DHF). A primary infection of dengue virus (DENV) was confirmed, specifically DENV serotype 2 (DENV-2), on the basis of the detection of the virus genome, a significant increase in the neutralizing antibody and the isolation of DENV-2. DHF is often observed following a secondary infection from another serotype of dengue virus, particularly in children, but this case was a primary infection of DENV. Japan is a non-endemic country for dengue disease. In fact, only Japanese encephalitis (JE) is known to be a member of the endemic flavivirus family. In this study, IgG antibody against Japanese encephalitis virus (JEV) was detected. JEV belongs to the family of dengue virus and prevails in Japan, particularly Kyushu. Among many risk factors for the occurrence of DHF, a plausible candidate could be a cross-reactive antibody-dependent enhancement (ADE) mechanism caused by JEV antibody. This indicates that most Japanese travelers who living in dengue non-endemic areas, particularly Kyushu, should be aware of the occurrence of DHF.

Experience on Identification of Cross-Reactive Group Specificity Performed by Anti-human Globulin Panel Reactive Antibody Tests / 대한진단검사의학회지

BACKGROUND: Panel reactive antibody (PRA) is to screen and identify HLA antibody. Majority of antibody specificities in high-PRA are directed against cross reactive group (CREG). Thus, this study was to know the advantage of identifying CREG specificity and whether antibody specificities are changed according to CREG classification. METHODS: HLA class I antibodies were identified from 159 sera from 108 patients in Asan Medical Center, who had shown more than 5% PRA by anti-human globulin (AHG)-complement-dependent cytotoxicity (CDC). Tail analysis-based computer program was developed to identify specificities, applying both Rodey (R-ABC) and Takemoto (T-ABC) classification. The results were also compared with those obtained when without CREG application (ABC). RESULTS: Among 151 cases in which HLA specificities was identified, the frequency of CREG specificity was 22.5% in R-ABC and 27.2% in T-ABC. Eleven cases showed CREG specificities only in one classification. However, the individual antigen specificities in one hand were all included in the CREG identified in the other hand. CREG specificities in samples with PRA >50% (60%) were more frequently identified than those in samples with PRA < or =50% (9%) (in R-ABC, P<0.0001). Without applying CREG to interpretation, specificity was not identified in 9 cases. CONCLUSIONS: Application of CREG enhanced the rate of antibody identification. Antibody specificities of those cases where CREG specificities were different between Rodey and Takemoto classifications were almost the same when compared at the individual antigen level. Therefore, it was thought that it makes no difference to use any one of these two classifications in interpreting PRA.

Application of human leukocyte antigen and cross-reactive group matching in clinical renal transplantation / 中华泌尿外科杂志

Objective To investigate the application and significance of human leukocyte antigen (HLA) and cross reactive groups(CREGs) matching in clinical renal transplantation. Methods A total of 312 cases of kidney transplantation were divided into two groups.In one group of 149 cases of kidney transplantations,ClassⅠCREGs matching criteria were applied instead of conventional HLA A,B matching which had two A,B mismatches(MM).In the other group of 163 cases of kidney transplantation there were A,B 0～2MM by the conventional criteria.The graft survival rate at 1 year and incidence of acute rejection within 1 month after transplantation were compared between the 2 groups. Results The percentages of HLA Ⅰ antigens 0,1,2MM were 16.7%,41.6% and 34.2% by CREGs matching criteria,and were 6.7 %,21.5% and 71.8% by conventional matching criteria.The matching rates in CREGs 0,1MM group were significantly higher than those in corresponding conventional matching group ( P 0.05);however,the incidence rate of CREGs 0MM group was obviously lower than that of A,B 2MM group ( P 0.05 ),but the rate of CREGs 0MM group was obviously higher than that of A,B 2MM group ( P

Application of Human Leukocyte Antigen Matching in Highly Sensitized Recipients of Renal Allografts / 中国医师杂志

40%)were observed in HLA CREGs matching and outcome of post-transplantation.Results Patients with 0,1,2 or 3 mismatching(MM) of HLA CREGs+DR were 4(28%), 6(44%)and 4(28%)cases respectively according to the the rule of CREGs matching and no case had 3～6 MM.However the cases of 0,1,2,3 and 4 MM were 1(7%),3(21%),5(36%)and 5(36%)respectively by the standard of conventional HLA antigen matching,without 4～6 MM and only 4 cases had shared 0～1MM.Only 9 patients were developed into acute rejection, and were reversed by OKT3 treatment after transplantation.Renal function was returned to normal in all patients.Conclusions Using CREGs matching criteria would significantly increase the chance of recipients to receive well-matched kidney and provide more chance for waiting recipients.Suitable HLA matching could play an important role in reducing the incidence of acute rejection and improving graft survival in sensitized patients.

Influence of Mismatching in HLA Cross-Reactive Group on the Graft Survival after Unrelated Kidney Transplantation / 대한임상병리학회지

BACKGROUND: Kidney transplantation(KT) from unrelated donors has been increasing in Korea in recent years. However, the number of HLA antigen mismatches in unrelated donor KTis larger compare with that in related donor KT. Recently, some studies have reported that cross-reactive group(CREG) matching would improve graft outcome. METHODS: We studied a total of 277 cases of kidney transplants from unrelated donors(cadaver donor 195 cases, living unrelated donor 82 cases) in our center from March 1992 to August 1998. HLA class I antigens were assigned to 10 CREG antigens based on the amino acid residue system of Takemoto. HLA-DR antigens were assigned to 10 broad HLA antigens. Antigens present in donor but not in recipient were considered as mismatches. The survival analysis was carried out by Kaplan-Meier method and differences in survival rates were tested by log-rank test. RESULTS: Mean numbers of mismatches in HLA and CREGs were 4.0 and 2.9. Mismatched numbers of CREG-A,B and 5 year survival rates showed a linear association(P=0.01), but those of HLA-A,B did not show a linear association(P=0.88). Probability of finding zero or one CREG mismatched recipients in unrelated KT was 53%(146 cases). A significant statistic difference was noted in survival rates between zero or one and two or more CREG mismatched group(P=0.01). CONCLUSION: Zero or one CREG mismatched group had better survival in unrelated living or cadaveric KT. Applying CREG matching strategy to recipient selection, graft survival will be significantly improved in unrelated living or cadaveric KT.

Establishment of an HLA-matched Platelet Donor Registry for the Management of Patients with Platelet Refractoriness / 대한수혈학회지

BACKGROUND: Heavily transfused patients commonly become refractory to platelet transfusion. Patients with platelet refractoriness due to HLA alloimmunization need HLA-matched platelet transfusion. We have established an hospital-based donor registry of HLA-typed platelet donors for the first time in Korea and evaluated the possibility of HLA-matched platelet supplies. METHODS: A total of 450 donors were registered and typed for HLA class I (A, B, C) antigens. A computer program was developed and used for the donor registry and HLA-matched donor search. A simulation study was performed on the availability of HLA-matched platelets for 100 patients from a pool of 450 donors. The availability of HLA-matched and cross reactive epitope group (CREG)-matched donors were analysed for HLA-A, B antigens. The CREGs defined by Fuller, Rodey, and UCLA criteria were used. RESLUTS: Among 100 patients, 63% had HLA-identical or HLA-matched (match grade: A, B1U, B2U) donors with only a low number of donors (mean 1.4) available per patient. Including CREG-matches (match grade: B1X, B2UX, B2X), majority (98%) of the patients had HLA- or CREG-matched (match grade: A~B2X) platelet donors with a higher number of donors (mean 26.6~40.5 by different CREG criteria) available per patient. Majority (86-98%) of the patients had 20 or more A~B4X matched donors, and about two thirds (61-74%) of the patients had 20 or more A~B2X matched donors. However, the number of ABO-identical matched donors was less than 30% of the total HLA- or CREG-matched donors. CONCLUSION: We established an HLA-matched platelet donor registry and using a donor pool size of < 500 donors, attainable in an hospital-based donor registry, the possibility of HLA-matched platelet supplies was confirmed in this study. However, for more satisfactory and ABO-matched platelet supplies a larger pool size is needed.