Antibodies In Different Groups Research Articles

Humoral immune response to SARS-CoV-2 in five different groups of individuals at different environmental and professional risk of infection

It is partially unknown whether the immune response to severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection persists with time. To address this issue, we detected the presence of SARS-CoV-2 antibodies in different groups of individuals previously diagnosed with COVID-19 disease (group 1 and 2), or potentially exposed to SARS-CoV-2 infection (group 3 and 4), and in a representative group of individuals with limited environmental exposure to the virus due to lockdown restrictions (group 5). The primary outcome was specific anti-SARS-CoV-2 antibodies in the different groups assessed by qualitative and quantitative analysis at baseline, 3 and 6 months follow-up. The seroconversion rate at baseline test was 95% in group 1, 61% in group 2, 40% in group 3, 17% in group 4 and 3% in group 5. Multivariate logistic regression analysis revealed male gender, close COVID-19 contact and presence of COVID-19 related symptoms strongly associated with serological positivity. The percentage of positive individuals as assessed by the qualitative and quantitative tests was superimposable. At the quantitative test, the median level of SARS-CoV-2 antibody levels measured in positive cases retested at 6-months increased significantly from baseline. The study indicates that assessing antibody response to SARS-CoV-2 through qualitative and quantitative testing is a reliable disease surveillance tool.

Seroprevalence of Toxoplasmosis at a Tertiary Care Centre in North India from 2004 to 2014

AbstractPurpose: This study was carried out to determine the seroprevalence of anti-Toxoplasma gondii antibodies in different groups of patients at a tertiary care hospital in North India. Materials and Methods: Clinical and demographic data such as age and gender of patients who had undergone testing for the presence of anti-T. gondii IgG and IgM antibodies between January 2004 and October 2014 were retrospectively analysed. Results: Amongst the 8397 serum samples, an overall seropositivity of 21% (n = 1763) and IgG and IgM seropositivity of 5.7% (n = 481) and 15.3% (n = 1282) were respectively observed. Compared to the period of 2004–2012 (median seroprevalence: 23.6%), a decline in seropositivity to 9.7% in 2013 and 8.1% in 2014 was noted. A rising seroprevalence with age and a higher seroprevalence in females versus males (29.5%, n = 1179 vs. 13.3%, n = 584) were recorded. The highest seroprevalence was observed in suspected ocular toxoplasmosis (47.2%, n = 47), followed by neurological (26.8%, n = 77), human immunodeficiency virus/acquired immunodeficiency syndrome (18.9%, n = 267), post-transplant (17.1%, n = 12) and congenital (7.2%, n = 144) toxoplasmosis. In patients screened for Toxoplasma exposure, the seropositivity was 47.8% (n = 11) in transplant screening and 44.9% (n = 781) in antenatal screening. Conclusion:Toxoplasma infection is highly prevalent in the population of North India across various clinical categories of patients. Future studies focusing on continuous monitoring of seroprevalence trends and elucidation of the risk factors associated with seropositivity in more defined groups of patients are needed.

Establishment of EA-D-IgA antibody detection method and its diagnostic efficacy for nasopharyngeal carcinoma in different clinical stage

Objective To establish a serological detection method for EA-D-IgA antibody, and to evaluate its diagnostic efficacy for nasopharyngeal carcinoma in different clinical stage. Methods EA-D-IgA antibody serological detection method was established by using the polypropylene microplate with eukaryotic expression product of BMRF1 whole gene fragment of EB virus. Fifteen early stage (stage Ⅰ and Ⅱ) and 48 advanced (stage Ⅲ and Ⅳ) patients with nasopharyngeal carcinoma in Shanxi Provincial Cancer Hospital and Shanxi Dayi Hospital from April 2012 to August 2017, and serum samples from 40 patients with rhinitis who were treated at Shanxi Dayi Hospital from October 2016 to October 2017 were examined respectively by using the constructed EA-D-IgA antibody detection method. The positive detection rate of EA-D-IgA antibodies in different groups was calculated. When the patients with rhinitis were used as the differential control, the diagnostic efficacy of this index for different stages of nasopharyngeal carcinoma was evaluated. Results EA-D-IgA antibody serological method was successfully established. The positive detection rate of EA-D-IgA antibody in early nasopharyngeal carcinoma, advanced nasopharyngeal carcinoma and rhinitis control was 60.0 % (10/15), 68.3 % (33/48) and 5.0 % (2/40) respectively. The differences between early stage nasopharyngeal carcinoma and the rhinitis control, advanced nasopharyngeal carcinoma and the rhinitis control were statistically significant (χ 2 = 20.625, P = 0.000; χ2 = 37.017, P = 0.000). The difference between early nasopharyngeal carcinoma and advanced nasopharyngeal carcinoma was not statistically significant (χ 2 = 0.394, P = 0.530). When compared with the patients with rhinitis, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value was 60.0 % and 68.3 %, 95.0 % and 95.0 %, 81.8 % and 94.3 %, 86.4 % and 71.7 % respectively in early nasopharyngeal carcinoma and advanced nasopharyngeal carcinoma. Conclusion The method constructed in this study effectively improves the efficacy of EA-D-IgA antibody detection in serological diagnosis of nasopharyngeal carcinoma, which can be used as an adjunct for early diagnosis of nasopharyngeal carcinoma, yet not as a reference for clinical staging. Key words: Nasopharyngeal neoplasms; BMRF1; Eukaryotic expression; Clinical staging; Diagnostic efficiency

Problems of Epidemiological Surveillance of West Nile Fever in Ukraine

ObjectiveTo define the problems of epidemiological surveillance of West Nile fever (WNF) in Ukraine.IntroductionFlaviviridae are one of the most widespread arboviruses in Ukraine. Mosquitoes are vectors of WNF in a majority of cases due to bites during swimming, fishing, work in suburban areas and outdoor recreation without use of individual protection from mosquitoes.A study of the species composition of bloodsucking mosquitoes is conducted in Ukraine. Existence of natural foci of WNF viruses has been well-proven all over the territory of Ukraine by testing IgG antibodies in different groups of population, including children [1]. Also, infection of mosquitoes (RNA found in Culex pipiens (including Culex pipiens f. molestus, Culiseta annulata)) was registered. Infection of I. ricinus and D. reticulates was also determined, and it acts as a factor for circulation of virus in the wild too [2].MethodsStatistical, serological and epidemiological methods were used during the study. Serological tests included reactions with IgM and IgG antibody in human serum performed using immunofluorescent and ELISA methods.ResultsIn Ukraine, the causative agent of WNF is detected in all landscapes. It is the main arboviral infection in the forest-steppe zone (53.1 % among all arboviral infections). Enzootic territories are located in 18 regions, 47 administrative districts, and 63 settlements.The majority of natural foci of WNF is located in the Dnieper left-bank steppes, and also in North-Western and Western forest-steppes. The enzootic territories are located on the East of steppe zone and on the East of forest-steppes. The smallest number of natural foci is registered in the Dnieper right-bank part of the steppes. Enzootic territories are absent in Chernivtsi, Chernihiv, Sumy, Ternopil, Luhansk, Kirovohrad Oblasts and Kyiv. Most of them are located in Zaporizhzhia with 9 administrative districts and 16 settlements; in Rivno Oblast - 7 and 9; in Kherson - 5 and 4, and in Poltava Oblasts - 2 and 4 respectively [3].During the period from 2007 to 2016, 86 cases of WNF were registered. WNF was registered in 7 oblasts (Zaporizhzhya - 40 cases, Poltava - 24, Donetsk - 16, Mykolaiv- 3, Kherson, Kharkiv, Zhytomyr Oblasts - one case in each) [4].Registration of WNF cases separately from other viral hemorrhagic fevers has been conducted in the country since 2010 (official registration of total amount of viral hemorrhagic fevers has been performed since 2005).In enzootic territories, 2 cases of the diseases were registered and were associated with ticks bites. The strains of WNV were detected in bloodsucking mosquitoes in Rivne and Zaporizhzhia Oblasts and in tick samples of Ixodes genus collected in Lviv Oblast (probably may be found in other species of tick (Argasidae and Gamazoidea) where the causative agent is kept in natural foci under unfavorable conditions).Laboratory diagnostics was conducted (mainly retrospectively) in Zaporizhzhia, Poltava, Donetsk Oblastss. All diagnoses (exception Mykolaiv Oblast in 2011, data is absent) were laboratory confirmed, including 10 cases confirmed in the State Institution Lviv Research Institute of Epidemiology and Hygiene of the Ministry of Health of Ukraine, and 3 more cases were confirmed by a private laboratory [2].In total, 129 samples of blood sera collected from patients with clinical manifestations of a fever of unknown origin were delivered to the Laboratory of Virology of Ukrainian Center for Diseases Control and Monitoring during 2016-2017. Samples were investigated using the immunofluorescent and enzyme immunoassay methods including immunoblot. West Nile virus markers such as IgM/IgG antibodies have been detected in 4 cases (Poltava oblast) [4].ConclusionsMainly, single cases were registered. It is caused by insufficient level of diagnostics in most of the regions, as a result, diseases pass under other diagnoses. Migratory birds (3 flyways of migratory birds pass through Ukraine) and local animals (crows, jackdaws, doves and other) may be the possible reservoirs of causative agent of WNF. Laboratory diagnostics need to be improved and more attention should be paid to testing of samples of blood serum from patients with suspected WNF.

Clinical significance of different antiphospholipid antibody isotypes in systemic lupus erythematosus

Objective To investigate the prevalence and clinical significance of different subtypes (IgG, IgM and IgA) of anticardiolipin antibodies (aCL) and anti-β2-glycoprotein I antibodies (aβ 2GP1), as well as lupus anticoagulant (LA) in systemic lupus erythematosus (SLE). Methods IgG/IgM/IgA, IgG, IgM, IgA aCL and anti-β2GP1 were tested by enzyme-linked immunosorbent assay (ELISA) in 100 patients with SLE (42 patients were diagnosed as secondary antiphospholipid syndrome), 44 healthy controls and 32 patients with other connective tissue diseases excluding SLE and antiphospholipid syndrome (APS). Meanwhile, LA was tested by modified Dilute Russell′s viper venom time (dRVVT). The correlation between antiphospholipid antibodies and clinical manifestation was analyzed by Spearman correlation analysis.The postiverate of antiphospholipid antibodies in SLE patients, health controls and patients with other connective tissue diseases were compared by chi square test. The concentrations of antiphospholipid antibodies in different groups were compared using independent sample Kruskal Wallis test. The diagnostic efficacy of antiphospholipid antibodies in SLE patients was analyzed by crosstable using clinical diagnosis of APS as gold standard. P<0.05 was considered statistically significant. Results The prevalence of IgG aCL(χ2=15.031 ,P<0.001), IgA/G/M (χ2=11.678, P=0.003) and IgA (χ2=6.17, P=0.036) anti-β2GP1 were significantly higher in patients with SLE than in the other two groups. IgA/G/M (r=0.207, P=0.039), IgG (r=0.230, P=0.021) and IgA (r=0.217, P=0.030) aCL, IgA/G/M (r=0.218, P=0.029) and IgA (r=0.255, P=0.01) anti-β2GP1, as well as LA (r=0.233, P=0.02) were associated with thrombotic events. IgA/G/M anti-β2GP1 (r=0.22, P=0.029) and LA (r=0.254, P=0.011) were associated with pathological pregnancy. 23.1% (6/26) aCL positive SLE patients were IgM and/or IgA aCL positive. 53.6% (15/28) anti-β2GP1 positive SLE patients were IgM and/or IgA anti-β2GP1 positive. In SLE patients, the specificity and sensitivity of IgA/G/M aCL for APS were 98.3% and 26.2%, respectively. The specificity and sensitivity of IgA/G/M anti-β2GP1 were 84.5% and 40.5%, respectively. The specificity of at least two isotypes positive for APS (both aCL and anti-β2GP1 were 98.3%), was higher than IgG aCL (94.8%) or anti-β2GP1 (93.1%). The sensitivity of at least one isotype of aCL (47.6%) or anti-β2GP1 (42.9%) positive for APS were higher than IgG aCL (40.5%) and anti-β2GP1 (21.4%). Conclusions IgG and IgM aCL together would be better than IgA/G/M aCL for APS screening. IgA/G/M anti-β2GP1 would be better for APS screen due to higher sensitivity and strong association with thromboembolic events and pathologic pregnance. IgA aCL or anti-β2GP1 was associated with thromboembolic events. IgA aCL or anti-β2GP1 would be useful for APS diagnosis in IgG and IgM aCL or anti-β2GP1 negative patients. （Chin J Lab Med,2014,37:597-602） Key words: Lupus erythematosus, systemic; Antiphospholipid syndrome; Immunoglobulins; Antibodies, anticardiolipin; beta 2-Glycoprotein I; Lupus coagulation inhibitor

Epidemiological Investigation of Measles in Sera of Healthy People in Heilongjiang Province, China

Serological samples of healthy people were collected to obtain the levels of measles antibodies in different groups of people in Heilongjiang Province, China. Using quantitative enzyme-linked immunosorbent assays to measure the antibody levels, we found the lowest antibody positive rate and the lowest geometric mean concentration values in healthy people aged 15-39. This group is the population at high risk for adult measles in Heilongjiang Province, and is the focus of measles elimination work. The new challenges for the eventual elimination of measles will be to address immunization strategies in this segment of the population in order to control the incidence.

Prevalence of HTLV-I Compared to HIV-1 and HIV-1 Antibodies in Different Groups on the Ivory Coast (West Africa)

Different Ivorian population groups were comparatively tested for antibodies to HTLV-1, HIV-1, and HIV-2. They included 1,334 healthy individuals, 176 unselected medical patients in regional hospitals, 149 female prostitutes, and 65 males with a sexually transmitted disease (STD) collected in 1987 from four regions (east, north, west, and central). The HTLV-1 prevalence averaged 1 to 2.7% in the different regions, without significant increase in sexually overexposed groups. Furthermore, in Dabou Protestant Hospital, 60 km west of Abidjan, 414 blood donors, 109 asymptomatic HIV-positive individuals, and 181 AIDS clinical cases were also tested. While a significant increase in the prevalence of HTLV-1 antibodies was observed only in AIDS patients. HIV-1 and HIV-2 prevalence increased, as expected, from a low rate (2.4%) in the general population to an intermediate rate (13-15%) in blood donors and unselected hospitalized patients and to a high rate (35%) in prostitutes and STD male patients.

Prevalence of HTLV-I Compared to HIV-1 and HIV-1 Antibodies in Different Groups on the Ivory Coast (West Africa)

Prevalence of HTLV-I Compared to HIV-1 and HIV-1 Antibodies in Different Groups on the Ivory Coast (West Africa)

Anti‐pre‐S antibodies in different groups of patients with hepatitis B virus infection

The anti-pre-S antibody in the samples of sera from normal healthy persons and patients with different clinical types of liver diseases due to hepatitis B virus (HBV) infection was detected by a newly established enzyme-linked immunosorbent assay technique. This test is a blocking assay where anti-pre-S antibody in the patient's serum blocks subsequent addition of horse radish peroxidase-labelled polymerized human serum albumin (pHSA) to the pHSA-receptor site of HBsAg molecules fixed on a solid surface. Anti-pre-S activity was not detected in any from 95 healthy persons who were negative for all HBV-markers or from 105 healthy HBV carriers. In 12 sera from HBV vaccine recipients, anti-pre-S activity was noted in higher proportions compared with anti-HBs, after both the second and third doses of vaccine. Anti-pre-S activity was detected in small proportions of HBsAg positive sera from acute viral hepatitis (4.2%) and chronic active hepatitis (10%). In subacute viral hepatitis patients, the anti-pre-S antibody was totally absent. However, anti-pre-S activity was recorded in high proportions of HBsAg-positive sera from patients with cirrhosis of liver (57.2%) and fulminant hepatitis (41.6%). The anti-pre-S antibodies were assumed to be implicated in the clearance of HBV particles from circulation without causing tissue damage.

Antisperm antibodies in infertile and homosexual men: relationship to serologic and clinical findings

The incidence and significance of antisperm antibodies in different groups of men were evaluated by a modified enzyme-linked immunosorbent assay. In serum, 4.0% of dermatologic patients (n = 223), 9.6% of andrologic patients (n = 178), and 28.6% of homosexual men (n = 42) were positive for IgG and/or IgM antibodies. In seminal fluids, 7.3% of the andrologic patients had IgA (and IgG) antibodies to spermatozoa. Only 1 of 29 positive men had antibodies both in serum and in seminal fluid. No correlation between antisperm antibodies and IgG/IgM concentrations was found in serum, whereas in seminal plasma men with antisperm antibodies showed higher IgG/IgA concentrations than men without (IgA, 3.2 versus 1.7 mg/dl; IgG, 9.8 versus 6.3 mg/dl). It is concluded that there is a high incidence of antisperm antibodies among homosexual men, probably because of contact of spermatozoa with the immune system by passive anal intercourse. There is little correlation between antisperm antibodies in serum and seminal plasma of infertile men because of a lack of relevant antibody transfer from the serum and the formation of local antibodies in seminal plasma. Antisperm antibodies in seminal fluid are associated with elevated local IgG and IgA concentrations.

Epstein-Barr Virus early antigen titer by immunofluorescence in microplates

For the titration of antibodies directed against Epstein-Barr Virus early antigen (EBV-EA) we describe a method in microplates with the Microtiter System (Cooke Engineering Co., Alexandria, Va). Using this technique, which allows rapid epidemiological investigations, we have titered anti-EBV-EA antibodies in different groups of patients and controls, and particularly in group which had recent contact with infectious mononucleosis. In this group the percentage of individuals having antibodies directed against the EBV-EA antigen was significantly higher than in the group of controls.

Distribution of Parainfluenza Antibodies in Different Groups of Population

Summary A study of parainfluenza antibodies in different population groups from the U. S. A., Italy and India, has shown that parainfluenza type 3 antibody is the most widely distributed among the three different populations, followed by type 1 and type 2. Evidence has been presented that the frequency of each parainfluenza antibody is similar in all three populations. All subjects with neutralizing antibodies also possessed the hemagglutination-inhibiting antibody, whereas the contrary was not always observed. No correlation was found between the presence of hemadsorption type 2 and Sendai antibody in individual sera.