scholarly journals Characteristics of convalescent plasma donors and their antibody titers in Bangladesh

2021 ◽  
Vol 8 (4) ◽  
pp. 480
Author(s):  
Ponkaj K. Datta ◽  
M. Mujibur Rahman ◽  
Ahmedul Kabir ◽  
M. Mazharul Hoque ◽  
Motlabur Rahman ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Qualitative Test ◽  
The Mean ◽  
Randomized Control ◽  
Donor Criteria ◽  
Donor Plasma

Background: Convalescent plasma is considered a promising therapy for severe COVID-19 disease. It is collected from the voluntary donors. Measurement of the antibody titer is necessary before transfusion to predict the outcome in the recipients. Characteristics of the convalescent plasma donors in Bangladesh and their antibody titers are not known.Methods: Convalescent plasma was collected from the voluntary donors who survived the COVID-19 disease to transfuse to the severe COVID-19 patients under a randomized control trial. Total IgG antibody titer was measured in the donor plasma by indirect enzyme-linked immunosorbent assay. Data was collected in a preformed questionnaire before donor plasma collection.Results: The median age is 32 (18-55) years.  Fever, cough, sore throat, diarrhea was most common among 68.3% of the symptomatic participants and the remaining 31.7% were asymptomatic at the time when they were RT-PCR positive. Overall, 57.1% of participants had mild symptoms, 11.1% had moderate symptoms and none had severe symptoms. Participants’ antibody titers were measured 41.68±14.072SD days after the RT-PCR positive date.  Rapid qualitative test could not detect antibody in 11 (17.5%) potential donors. Of the remaining 52 (82.5%) antibody positive participants titer was measured in 43 participants and found 1:320 in 17 (27.0%) (n=63), 1:160 in another 17 (27.0%) (n=63) and 1:80 in rest of the 9 (14.28%) (n=63) Participants. The mean titer of the donors who were hospitalized during their illness (1:274.29) was statistically significantly higher (p=0.043, CI>95%). The mean titer was also higher in female than in male, symptomatic than asymptomatic participants and in donors of A positive blood group. However, these finding are not statistically significant. Antibody titer does not correlate with time of RT-PCR negativity from initial RT-PCR positivity, time from RT-PCR positivity to titer date, age and body mass index.Conclusions: All RT-PCR positive COVID-19 patients subsequently may not develop antibody. Although antibody titer among hospitalized symptomatic patients was significantly higher, further study is needed to recommend optimal convalescent plasma donor criteria. 

scholarly journals Anti-S. typhi Vi IgG levels in children with and without typhoid vaccinations

2014 ◽  
Vol 54 (5) ◽  
pp. 284
Author(s):  
Sriandayani Sriandayani ◽  
Tonny H. Rampengan ◽  
Hesti Lestari ◽  
Novie Rampengan
Keyword(s):  
Typhoid Fever ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Igg Antibody ◽  
Protective Antibody ◽  
Significant Difference ◽  
Antibody Titers ◽  
The Mean ◽  
And Gender ◽  
Antibody Levels

Background Typhoid fever is endemic to Indonesia, with an annual incidence of 13/10,000 people. Vaccination has been shown to be an effective method to prevent typhoid fever. Of several vaccine types, the polysaccharide Vi vaccine is the most commonly used typhoid vaccine in developing countries. Results of previous studies remain inconclusive on the necessity of revaccination every 3 years.Objective To compare the mean serum anrioody titers of anti-S. typhi Vi IgG and the proportion of children with protective antibody levels between children with and without typhoid Vi vaccination.Methods We conducted a cross-secrional study at Tuminring District, 11anado from June to September 2012. Data was analyzed using independent T-test and Fisher's test. Serum anti-S. typhi Vi IgG levels were measured by enzyme-linked immunosorbent assay (ELISA) method.Results Seventy-six subjects were divided into two groups: 38 children who had received the typhoid Vi vaccination more than 3 years prior to this study and 38 children who never had typhoid vaccinations as a control group. No statistically significant difference in age and gender was found between the two groups. The mean serum anti-Vi IgG level was 0.55 ug/mL (SD 0.58; 95%CI 0.36 to 0.74) in the vaccinated group, significantly higher than that of the control group [0.31 ug/mL (SD 0.12); 950/£1 0.17 to 0.44; P􀂥0.0381. The proportion of children with protective antiNi antioody level was higher in the vaccinated group (23.7%) than in the control group  (10.5%), howevet; this difference was not statistically significant (P=0.128).Conclusion The mean serum anti-S. typhi Vi IgG antibody level in children who had been vaccinated more than 3 years prior to the study is higher than in children who had never received typhoid vaccinations. Nevertheless, the mean antibody titers are generally non-protective in ooth groups. Also, the proportion of children with protective antibody levels is not significantly different between the two groups.

scholarly journals Antibody level of New Zealand children immunized with the triple vaccine DTP (diphtheria-tetanus-pertussis)

1988 ◽  
Vol 101 (2) ◽  
pp. 405-410 ◽  
Author(s):  
R. C. H Lau
Keyword(s):  
New Zealand ◽  
Immunosorbent Assay ◽  
Antibody Level ◽  
Herd Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Immunization Strategy ◽  
The Mean ◽  
Antibody Levels

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.

scholarly journals Detection of antibodies to recombinant truncated flagellin and sonicated whole cell antigen of Burkholderia pseudomallei in acute melioidosis and in healthy Bangladeshi individuals

2020 ◽  
Vol 14 (1) ◽  
pp. 47-52
Author(s):  
Md Shariful Alam Jilani ◽  
Tang Thean Hock ◽  
Sraboni Mazumder ◽  
Fahmida Rahman ◽  
Md Mohiuddin ◽  
...  
Keyword(s):  
Rural Areas ◽  
Burkholderia Pseudomallei ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Igg Antibody ◽  
Whole Cell ◽  
Cell Antigen ◽  
The Mean

Background and objectives: Several types of Burkholderia pseudomallei antigens have been used to determine the antibody response in acute and asymptomatic cases. In the present study, we have detected immunoglobulin G (IgG) antibody to recombinant truncated flagellin antigen (RTFA) of B. pseudomallei in the sera of acute melioidosis cases and healthy individuals from melioidosis endemic areas of Bangladesh by indirect enzyme-linked immunosorbent assay (ELISA). In parallel, IgG antibody to sonicated whole cell antigen (SWCA) of B. pseudomallei was determined to compare with anti-RTFA antibody. Methodology: Serum samples from culture confirmed melioidosis cases and from healthy individuals aged 21 years and above residing in melioidosis endemic rural areas were included in the study. Serum IgG antibody to RTFA and SWCA of B. pseudomallei was determined by indirect ELISA. Results: Out of 8 culture confirmed acute melioidosis cases, 7 (87.5%) and 8 (100%) were positive for anti-B. pseudomallei IgG antibodies by RTFA and SWCA methods respectively. Among 361 healthy individuals, the rate of seropositivity by RTFA-ELISA was significantly less than that of SWCA-ELISA (16.1% versus 26.8%; p = 0.001). The mean optical density (OD) of RTFA-ELISA of positive cases was significantly less than that of SWCA-ELISA in both melioidosis and healthy individuals (0.79±0.11 versus 2.4±0.08, p = 0.0001; 0.67±0.01 versus 1.27±0.02, p = 0.0001). The sensitivity and specificity of RTFA-ELISA were 88.9% and 100% respectively. Conclusion: Findings of the study suggest that multiple or combination of antigens should be used to study the seroprevalence of B. pseudomallei infection in a community. Also, prospective study is necessary to find out the duration of persistence of antibodies to different antigenic components of B. pseudomallei after exposure. Ibrahim Med. Coll. J. 2020; 14(1): 47-52

scholarly journals Pneumococcal Type 22F Polysaccharide Absorption Improves the Specificity of a Pneumococcal-Polysaccharide Enzyme-Linked Immunosorbent Assay

2001 ◽  
Vol 8 (2) ◽  
pp. 266-272 ◽  
Author(s):  
Nelydia F. Concepcion ◽  
Carl E. Frasch
Keyword(s):  
Correlation Coefficient ◽  
Immunosorbent Assay ◽  
Pneumococcal Vaccination ◽  
Correlation Coefficients ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Functional Activities ◽  
Antibody Titers ◽  
The Common ◽  
Elisa Inhibition

ABSTRACT The specificity of the immune response to the 23-valent pneumococcal-polysaccharide (PS) vaccine in healthy adults and to a pneumococcal conjugate vaccine in infants was examined by measuring immunoglobulin G (IgG) antibody titers by enzyme-linked immunosorbent assay (ELISA) and the opsonophagocytosis assay. ELISA measures total antipneumococcal IgG titers including the titers of functional and nonfunctional antibodies, while the opsonophagocytosis assay measures only functional-antibody titers. Twenty-four pairs of pre- and post-pneumococcal vaccination sera from adults were evaluated (ELISA) for levels of IgG antibodies against serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F. Twelve of the pairs were also examined (opsonophagocytosis assay) for their functional activities. The correlation coefficients between assay results for most types ranged from 0.75 to 0.90, but the correlation coefficient was only about 0.6 for serotypes 4 and 19F. The specificities of these antibodies were further examined by the use of competitive ELISA inhibition. A number of heterologous polysaccharides (types 11A, 12F, 15B, 22F, and 33A) were used as inhibitors. Most of the sera tested showed cross-reacting antibodies, in addition to those removed by pneumococcal C PS absorption. Our data suggest the presence of a common epitope that is found on most pneumococcal PS but that is not absorbed by purified C PS. Use of a heterologous pneumococcal PS (22F) to adsorb the antibodies to the common epitope increased the correlation between the IgG ELISA results and the opsonophagocytosis assay results. The correlation coefficient improve from 0.66 to 0.92 for type 4 and from 0.63 to 0.80 for type 19F. These common-epitope antibodies were largely absent in infants at 7 months of age, suggesting the carbohydrate nature of the epitope.

Detection of Respiratory and Enteric Shedding of Bovine Coronaviruses in Cattle in an Ohio Feedlot

2002 ◽  
Vol 14 (4) ◽  
pp. 308-313 ◽  
Author(s):  
Mustafa Hasoksuz ◽  
Armando E. Hoet ◽  
Steven C. Loerch ◽  
Thomas E. Wittum ◽  
Paul R. Nielsen ◽  
...  
Keyword(s):  
Agricultural Research ◽  
Clinical Signs ◽  
Feedlot Cattle ◽  
N Gene ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Fecal Shedding ◽  
Enteric Infections ◽  
Antibody Titers ◽  
Feedlot Calves

Recently, bovine coronavirus (BCV) has been isolated from new cattle arrivals to feedlots, but the association between respiratory and enteric infections with BCV in feedlot cattle remains uncertain. Fecal and nasal swab samples from 85 Ohio Agricultural Research and Development Center (OARDC) feedlot cattle averaging 7 months of age were collected at arrival (0) and at 4, 7, 14, and 21 days postarrival (DPA). An antigen capture enzyme-linked immunosorbent assay (ELISA) was used to detect concurrent shedding of BCV in fecal and nasal samples. All samples ELISA positive for BCV were matched with an equal number of BCV ELISA-negative samples and analyzed by reverse transcription-polymerase chain reaction (RT-PCR) of the N gene. Paired sera were collected at arrival and 21 DPA and tested for antibodies to BCV using an indirect ELISA. Information on clinical signs, treatments provided, and cattle weights were collected. The overall rates of BCV nasal and fecal shedding were 48% (41/85) and 53% (45/85) by ELISA and 84% (71/85) and 96% (82/85) by RT-PCR, respectively. The peak of BCV nasal and fecal shedding occurred at 4 DPA. Thirty-two cattle (38%) showed concurrent enteric and nasal shedding detected by both tests. Eleven percent of cattle had antibody titers against BCV at 0 DPA and 91% of cattle seroconverted to BCV by 21 DPA. The BCV fecal and nasal shedding detected by ELISA and RT-PCR were statistically correlated with ELISA antibody seroconversion ( P < 0.0001); however, BCV fecal and nasal shedding were not significantly related to clinical signs. Seroconversion to BCV was inversely related to average daily weight gains ( P < 0.06). Twenty-eight respiratory and 7 enteric BCV strains were isolated from nasal and fecal samples of 32 cattle in HRT-18 cell cultures. These findings confirm the presence of enteric and respiratory BCV infections in feedlot calves. Further studies are needed to elucidate the differences between enteric and respiratory strains of BCV and their role in the bovine respiratory disease complex of feedlot cattle.

scholarly journals Protective Immune Responses to the 42-Kilodalton (kDa) Region of Plasmodium yoelii Merozoite Surface Protein 1 Are Induced by the C-Terminal 19-kDa Region but Not by the Adjacent 33-kDa Region

2002 ◽  
Vol 70 (2) ◽  
pp. 820-825 ◽  
Author(s):  
Niklas Ahlborg ◽  
Irene T. Ling ◽  
Wendy Howard ◽  
Anthony A. Holder ◽  
Eleanor M. Riley
Keyword(s):  
Gene Segment ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Merozoite Surface Protein 1 ◽  
Antibody Titers ◽  
Processing Product

ABSTRACT Vaccination of mice with the 42-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP142) or its 19-kDa C-terminal processing product (MSP119) can elicit protective antibody responses in mice. To investigate if the 33-kDa N-terminal fragment (MSP133) of MSP142 also induces protection, the gene segment encoding MSP133 was expressed as a glutathione S-transferase (GST) fusion protein. C57BL/6 and BALB/c mice were immunized with GST-MSP133 and subsequently challenged with the lethal P. yoelii YM blood stage parasite. GST-MSP133 failed to induce protection, and all mice developed patent parasitemia at a level similar to that in naive or control (GST-immunized) mice; mice immunized with GST-MSP119 were protected, as has been shown previously. Specific prechallenge immunoglobulin G (IgG) antibody responses to MSP1 were analyzed by enzyme-linked immunosorbent assay and immunofluorescence. Despite being unprotected, several mice immunized with MSP133 had antibody titers (of all IgG subclasses) that were comparable to or higher than those in mice that were protected following immunization with MSP119. The finding that P. yoelii MSP133 elicits strong but nonprotective antibody responses may have implications for the design of vaccines for humans based on Plasmodium falciparum or Plasmodium vivax MSP142.

scholarly journals A Modified Enzyme-Linked Immunosorbent Assay for Measurement of Antibody Responses to Meningococcal C Polysaccharide That Correlate with Bactericidal Responses

1998 ◽  
Vol 5 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Dan M. Granoff ◽  
Susan E. Maslanka ◽  
George M. Carlone ◽  
Brian D. Plikaytis ◽  
George F. Santos ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Geometric Mean ◽  
Correlation Coefficients ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Avidity ◽  
Igg Antibody ◽  
Standard Assay ◽  
Bactericidal Antibody ◽  
Antibody Titers

ABSTRACT The standardized enzyme-linked immunosorbent assay (ELISA) for measurement of serum immunoglobulin G (IgG) antibody responses to meningococcal C polysaccharide has been modified to employ assay conditions that ensure specificity and favor detection primarily of high-avidity antibodies. The modified and standard assays were used to measure IgG antibody concentrations in sera of toddlers vaccinated with meningococcal polysaccharide vaccine or a meningococcal C conjugate vaccine. The results were compared to the respective complement-mediated bactericidal antibody titers. In sera obtained after one or two doses of vaccine, the correlation coefficients, r, for the results of the standard assay and bactericidal antibody titers were 0.45 and 0.29, compared to 0.85 and 0.87, respectively, for the modified assay. With the standard assay, there were no significant differences between the geometric mean antibody responses of the two vaccine groups. In contrast, with the modified assay, 5- to 20-fold higher postvaccination antibody concentrations were measured in the conjugate than in the polysaccharide group. Importantly, the results of the modified assay, but not the standard ELISA, paralleled the respective geometric mean bactericidal antibody titers. Thus, by employing conditions that favor detection of higher-avidity IgG antibody, the modified ELISA provides results that correlate closely with measurements of antibody functional activity that are thought to be important in protection against meningococcal disease.

scholarly journals A Paradoxical Screening Serological Assay for the Diagnosis of Whipple’s Disease (infection with Tropheryma whipplei)

2021 ◽  
Author(s):  
K.C. Liew ◽  
Chelsea Nguyen ◽  
Nilakshi T Waidyatillake ◽  
John Stenos ◽  
Aaron Walton ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Characteristic Curve ◽  
Tropheryma Whipplei ◽  
Whipple’S Disease ◽  
Igg Antibody ◽  
Whipple's Disease ◽  
Serological Assay ◽  
Igm Antibody ◽  
Antibody Titers

ABSTRACTWhipple’s disease (WD) is a rare infection due to Tropheryma whipplei. Following in-vitro cultivation of T. whipplei, an indirect-immunofluorescence serological assay (IFA) was developed. We tested the hypothesis that this assay could be used to either identify WD patients, or rule out WD, in patients in whom the diagnosis is being considered, based on the antibody titers of their IgM and IgG antibody responses. In this small study fourteen WD patients and 22 healthy volunteers’ sera were obtained from across Australia. All specimens were coded and de-identified before testing. A patient with an IgG antibody titer of ≤1:16 may have WD [sensitivity 57% (8/14) and specificity close to 100% (22/22)]. High IgM antibody titers (≥1:256) were more common in WD patients [sensitivity 50% (7/14) and specificity 86% (19/22)] than in controls. The area under Receiver-Operator-Characteristic curve for IgG in the IFA assay was 0.84 (95% CI 0.69-1.00). At an IgG antibody titer of ≤1:16 the Youden’s index was 0.57. WD patients’ under-produce IgG antibody to T.whipplei but are more likely to over-produce IgM antibodies. This screening IFA serological assay may be clinically useful in detecting those with a possible diagnosis of WD. Patients with an IgG antibody titer of ≤1:16 and an IgM antibody titer of ≥1:256 may have WD and should proceed to a tissue biopsy and PCR for confirmation. Further validation of this assay, by increasing the sample size, by testing it in patients with non-WD disease and trialing in other countries should be undertaken.

scholarly journals Development of Enzyme Linked Immunosorbent Assay for humoral immuneresponse and infection monitoring of anthrax

2020 ◽  
Vol 71 (1) ◽  
pp. 1935
Author(s):  
H. R. NOURI ◽  
H. RAZZAZ ◽  
M. TAGHDIRI ◽  
K. TADAYON ◽  
S. R. BANIHASHEMI
Keyword(s):  
Protective Antigen ◽  
Critical Role ◽  
Lethal Factor ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Elisa Kit ◽  
Gram Positive Bacteria ◽  
Anthrax Lethal Factor ◽  
Antibody Titers ◽  
Immune Assays

Immune assays were taken into consideration to diagnose and quantify metabolites such as antigen and antibody. Enzyme-Linked Immunosorbent Assays (ELISAs), which are used to detect antigens and antibodies, generated several periods of infectious and vaccination conditions. There is an extensive range of commercial infectious disease ELISA kits useful for the detection of human and animal IgG, IgA, IgM antibodies and microorganism antigens. Anthrax is one of the serious infectious diseases caused by rod-shaped, gram-positive bacteria known as Bacillus anthracis. Subunit or attenuated vaccines applied against anthrax disease increase the antibody against the Protective Antigen (PA) which has a critical role as a toxin of B. anthracis. Herein, the ELISA was developed using PA domain 4 and anthrax Lethal Factor to detect IgG antibody in serum. Besides, the level of anti-LF antibodies were determined as a complementary test to measure variance in antibody titers associated with vaccination or infection that leads to detection of anthrax in livestock. The results show that we developed high-quality ELISA kit that can be used to test immunogenicity of vaccines and infections in mice. We tried to develop the Anti- PA4 ELISA kit and conduct the validation studies to evaluate the fluctuation level of the antibody in the anthrax vaccine and distinction between disease and vaccination in mice.

scholarly journals An enzyme-linked immunosorbent assay for platelet compatibility testing

Blood ◽  
1983 ◽  
Vol 62 (4) ◽  
pp. 744-749 ◽  
Author(s):  
JD Tamerius ◽  
JG Curd ◽  
P Tani ◽  
R McMillan
Keyword(s):  
Antibody Titer ◽  
Immunosorbent Assay ◽  
Clinical Laboratory ◽  
Clinical Problem ◽  
Enzyme Linked Immunosorbent Assay ◽  
Microtiter Plates ◽  
Volunteer Donor ◽  
Antibody Titers ◽  
Test Serum ◽  
Selection Of

Abstract The selection of platelet donors for patients who are refractory to random donor platelets often presents a difficult clinical problem. We describe an enzyme-linked immunosorbent assay (ELISA) for evaluating alloantibodies in refractory patients. Platelets from prospective donors are immobilized on microtiter plates and, after incubation with test serum and washing, platelet-bound IgG is detected with enzyme- linked anti-human IgG. Platelets from 46 prospective donors were tested. Twenty-two were judged compatible (reciprocal of the antibody titer less than 16) and, of these, 15 were used as platelet donors; each gave a measurable platelet increment after transfusion. The magnitude of the response was roughly proportional to the assay results. Platelets from donors giving antibody titers less than 4 resulted in platelet increments at 1 hr ranging from 4,890 to 22,200 (median 12,600), while platelets from donors giving titers of 8 or 16 resulted in lesser increments (550–4548). Conversely, 5 of the 24 patients found incompatible by the assay (titer greater than 16) gave no platelet increment, and in 3 instances, the recipient developed fever and chills after the transfusion. The assay is sensitive, simple, and adaptable to the clinical laboratory. Platelets from volunteer donor panels can be plated and stored for up to 6 mo.

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