scholarly journals Diagnostic Implications of Antigen-Induced Gamma Interferon Production by Blood Leukocytes from Mycobacterium bovis-Infected Reindeer (Rangifer tarandus)

2006 ◽  
Vol 13 (1) ◽  
pp. 37-44 ◽  
Author(s):  
W. R. Waters ◽  
M. V. Palmer ◽  
R. E. Slaughter ◽  
S. L. Jones ◽  
J. E. Pitzer ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Skin Testing ◽  
The United States ◽  
Gamma Interferon ◽  
Tuberculin Skin Testing ◽  
Blood Leukocytes ◽  
Vitro Assay ◽  
Apparent Lack ◽  
Ifn Γ

ABSTRACT The only approved method of tuberculosis (TB) surveillance of reindeer within the United States is tuberculin skin testing; however, skin testing has an apparent lack of specificity, since numerous reindeer are classified as reactors, yet Mycobacterium bovis is not isolated from tissues upon necropsy. The objective of this study was to evaluate the ability of an in vitro assay (the Cervigam assay) to detect gamma interferon (IFN-γ) produced by blood leukocytes in response to mycobacterial antigens from M. bovis-infected reindeer. Thirteen male reindeer ∼9 months of age were inoculated with 105 CFU M. bovis in their tonsillar crypts. Stimulation of whole-blood cultures with a mitogen resulted in significant production of IFN-γ compared to that by nonstimulated samples. Responses by infected reindeer to M. bovis purified protein derivative (PPD) were as much as 3.5-fold higher than those by noninfected reindeer (n = 4). Despite differences in responses to PPD by the two groups, reindeer within the noninfected group had responses of >0.1 change in optical density (ΔOD) (a level generally considered positive) to PPD. Mean responses by infected reindeer to a rESAT-6-CFP-10 fusion protein (Mycobacterium tuberculosis complex specific) were as much as 20-fold higher than respective responses by noninfected reindeer at all time points. Additionally, responses by 3/4 noninfected reindeer were <0.1 ΔOD (considered negative) at each time point. To further evaluate the specificity of the assay, samples were collected from reindeer in a TB-free herd. All reindeer had responses to mitogen; however, only 1 of 38 had a response to PPD, and none of the reindeer responded to rESAT-6-CFP-10. Together, these findings indicate that IFN-γ-based tests may prove useful for TB surveillance of reindeer.

scholarly journals Development of a Human Gamma Interferon Enzyme Immunoassay and Comparison with Tuberculin Skin Testing for Detection ofMycobacterium tuberculosis Infection

1998 ◽  
Vol 5 (4) ◽  
pp. 531-536 ◽  
Author(s):  
Nuket Desem ◽  
Stephen L. Jones
Keyword(s):  
Enzyme Immunoassay ◽  
Skin Test ◽  
Skin Testing ◽  
Gamma Interferon ◽  
Tuberculin Skin Testing ◽  
In Vitro Test ◽  
Detection Range ◽  
Ifn Γ

ABSTRACT A sensitive two-step simultaneous enzyme immunoassay (EIA) for human gamma interferon (IFN-γ) has been developed and used as an in vitro test for human tuberculosis (TB) in comparison with tuberculin skin testing. The EIA was shown to be highly sensitive, detecting less than 0.5 IU of recombinant human IFN-γ per ml within a linear detection range of 0.5 to 150 IU/ml. The assay was highly reproducible and specific for native IFN-γ. In addition, the assay detected chimpanzee, orangutan, gibbon, and squirrel monkey IFN-γs. Cross-reactions with other human cytokines or with IFN-γs derived from mice, cattle, or Old World monkeys were not evident. The assay was used to detect TB infection by incubating whole blood overnight with human, avian, and bovine tuberculin purified protein derivatives (PPDs), as well as positive (mitogen)- and negative-control preparations. The levels of IFN-γ in plasma supernatants were then determined. Blood from 10 tuberculin skin test-positive individuals responded predominantly to the human tuberculin PPD antigen and to a lesser extent to bovine and avian PPD antigens. By contrast, blood from 10 skin test-negative individuals showed minimal responses or no response to any of the tuberculin PPDs. Detectable levels of IFN-γ were present in all blood samples stimulated with mitogen. In vivo tuberculin reactivity was correlated with IFN-γ responsiveness in vitro. These results support the further study of the blood culture–IFN-γ EIA system as an alternative to skin testing for the detection of human TB infection.

scholarly journals Effects of Different Tuberculin Skin-Testing Regimens on Gamma Interferon and Antibody Responses in Cattle Experimentally Infected with Mycobacterium bovis

2006 ◽  
Vol 13 (3) ◽  
pp. 387-394 ◽  
Author(s):  
M. V. Palmer ◽  
W. R. Waters ◽  
T. C. Thacker ◽  
R. Greenwald ◽  
J. Esfandiari ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Antibody Production ◽  
Positive Response ◽  
Skin Testing ◽  
Gamma Interferon ◽  
Antibody Responses ◽  
Confirmatory Test ◽  
Tuberculin Skin Testing ◽  
Holstein Calves ◽  
Ifn Γ

ABSTRACT Although tuberculin skin testing has been a hallmark of bovine tuberculosis eradication campaigns, it lacks sensitivity, can be confounded by exposure to nontuberculous mycobacteria, and cannot be repeated for 60 days due to desensitization. To overcome these difficulties, an effective whole-blood cellular immunoassay for bovine gamma interferon (IFN-γ) has been developed. The IFN-γ test is commonly used in conjunction with tuberculin skin testing as a confirmatory test following a positive response to the caudal fold test (CFT). The present study was conducted to determine the effect of different tuberculin skin-testing regimens on IFN-γ and antibody production by using calves that were experimentally infected with Mycobacterium bovis. Holstein calves were CFT tested 60 days after inoculation and the comparative cervical test (CCT) was conducted 7 (7-day CCT) or 55 (55-day CCT) days after the CFT. In both the 7-day CCT and 55-day CCT groups, IFN-γ responses increased 3 days after the CFT; this was immediately followed by a decrease to pre-skin test levels 7 days after the CFT. In both groups, the application of the CCT at 7 or 55 days after the CFT resulted in no significant increase in IFN-γ production. The administration of the CFT and the CCT to M. bovis-inoculated cattle boosted antibody responses to M. bovis PPD, rMPB83, ESAT-6, and the fusion protein Acr1-MPB83. The boosting effect was more pronounced in the 55-day CCT group. Increases in either IFN-γ or antibody production were not seen in noninoculated cattle. Measurement of both IFN-γ and antibody responses after skin testing may be useful in identifying M. bovis-infected cattle; however, the timing of collection of such samples may influence interpretation.

scholarly journals Virulent Mycobacterium fortuitum Restricts NO Production by a Gamma Interferon-Activated J774 Cell Line and Phagosome-Lysosome Fusion

2002 ◽  
Vol 70 (10) ◽  
pp. 5628-5634 ◽  
Author(s):  
Tânia Regina Marques da Silva ◽  
Juliana Ribeiro de Freitas ◽  
Queilan Chagas Silva ◽  
Cláudio Pereira Figueira ◽  
Eliana Roxo ◽  
...  
Keyword(s):  
Gamma Interferon ◽  
No Production ◽  
Mycobacterium Fortuitum ◽  
Vitro Assay ◽  
J774 Cells ◽  
Nitrogen Radicals ◽  
Ifn Γ ◽  
Phagosome Fusion ◽  
J774 Cell Line

ABSTRACT The virulence of different isolates of Mycobacterium has been associated with two morphologically distinguishable colonial variants: opaque (SmOp) and transparent (SmTr). In this report we used an in vitro assay to compare macrophage (Mφ) responses to SmOp and SmTr Mycobacterium fortuitum variants, taking advantage of the fact that these variants were derived from the same isolate. Cells preactivated or not with gamma interferon (IFN-γ) were infected with SmOp or SmTr M. fortuitum. We showed that SmOp and SmTr induced different levels of nitric oxide (NO) production by IFN-γ-stimulated Mφ. Indeed, the amount of IFN-γ-induced NO production by J774 cells was 4.8 to 9.0 times higher by SmOp (23.1 to 37.7 μM) compared to SmTr infection (3.9 to 4.8 μM) (P = 0.0332), indicating that virulent SmTr bacilli restricted NO production. In addition, IFN-γ-induced NO production by Mφ was higher when correlated with reduction of only avirulent SmOp bacillus viability. SNAP (S-nitroso-N-acetyl-dl-penicillamine)-induced NO production did not modify SmTr viability, indicating its resistance to nitrogen radicals. Electron microscopy studies were performed to evaluate the capacity of phagosomes to fuse with lysosomes labeled with bovine serum albumin-colloidal gold particles. By 24 h postinfection, 69% more phagosome-containing SmOp variant had fused with lysosomes compared to the SmTr-induced phagosomes. In conclusion, these data indicate that virulent SmTr bacilli may escape host defense by restricting IFN-γ-induced NO production, resisting nitrogen toxic radicals, and limiting phagosome fusion with lysosomes.

scholarly journals Development and Evaluation of a Real-Time Reverse Transcription-PCR Assay for Quantification of Gamma Interferon mRNA To Diagnose Tuberculosis in Multiple Animal Species

2007 ◽  
Vol 14 (12) ◽  
pp. 1563-1571 ◽  
Author(s):  
Noel P. Harrington ◽  
Om P. Surujballi ◽  
W. Ray Waters ◽  
John F. Prescott
Keyword(s):  
Mrna Expression ◽  
Real Time ◽  
Reverse Transcription ◽  
Skin Testing ◽  
Gamma Interferon ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sequence Information ◽  
Tuberculin Skin Testing ◽  
Reverse Transcription Pcr ◽  
Ifn Γ

ABSTRACT Tuberculosis of free-ranging and captive wildlife, including species implicated in the maintenance and transmission of Mycobacterium bovis, is a difficult disease to diagnose and control. Historically, diagnosis of tuberculosis has relied largely upon assays of cell-mediated immunity (CMI), such as tuberculin skin testing. This approach, however, is problematic or impractical for use with many wildlife species. Increasingly, in vitro diagnostic tests, including gamma interferon (IFN-γ)-based assays, are replacing or complementing skin testing of cattle and humans. Analogous assays are unavailable for most wildlife because of a lack of species-specific immunological reagents. This report describes the development and validation of a whole-blood assay to quantify antigen-specific IFN-γ mRNA expression by quantitative real-time reverse transcription-PCR. Oligonucleotide primers and probes were designed and tested for reactivity towards several susceptible species of interest with respect to tuberculosis infection. The assay was subsequently optimized to quantify the IFN-γ mRNA expression in elk and red deer (Cervus elaphus) and was evaluated for its ability to detect mycobacterial antigen-specific responses of experimentally tuberculosis-infected animals. The assay was a simple, rapid, and sensitive measure of antigen-specific CMI. The IFN-γ mRNA responses correlated well with IFN-γ protein production and showed performance in determining an animal's infection status superior to that of either lymphocyte proliferation or IFN-γ protein enzyme-linked immunosorbent assay methods. An additional advantage is the ease with which the assay can be modified to reliably quantify IFN-γ expression by using consensus sequences of closely related species or of other species for which IFN-γ sequence information is available.

scholarly journals T-Cell mRNA Expression in Response to Mycobacterium bovis BCG Vaccination and Mycobacterium bovis Infection of White-Tailed Deer

2009 ◽  
Vol 16 (8) ◽  
pp. 1139-1145 ◽  
Author(s):  
Tyler C. Thacker ◽  
Mitchell V. Palmer ◽  
W. Ray Waters
Keyword(s):  
T Cell ◽  
Mrna Expression ◽  
Mycobacterium Bovis ◽  
Lesion Group ◽  
Effective Vaccine ◽  
Blood Leukocytes ◽  
Visible Lesion ◽  
Gata3 Expression ◽  
Ifn Γ

ABSTRACT Understanding immune responses of white-tailed deer (WTD) to infection with Mycobacterium bovis provides insight into mechanisms of pathogen control and may provide clues to development of effective vaccine strategies. WTD were vaccinated with either M. bovis BCG strain Pasteur or BCG strain Danish. Both vaccinees and unvaccinated controls were subsequently inoculated with virulent M. bovis via the intratonsillar route. Real-time PCR was used to assess T-cell mRNA expression in peripheral blood leukocytes (PBL) from animals following vaccination and infection. Recall T-cell responses were measured by assessing the relative expression of gamma interferon (IFN-γ), T-cell-specific T-box transcription factor (Tbet), interleukin 12p40 (IL-12p40), IL-12p35, IL-23p19, FoxP3, IL-17, and GATA3 in PBL stimulated in vitro with purified protein derivative (PPD) of M. bovis or a recombinant fusion protein, ESAT6-CFP10. Animals vaccinated with BCG Danish expressed more IFN-γ and Tbet than either BCG Pasteur-vaccinated animals or unvaccinated controls. BCG Pasteur-vaccinated animals expressed more GATA3 than either group. After infection, unvaccinated controls expressed more Tbet and IL-12p40 than vaccinated animals. BCG Pasteur-vaccinated animals expressed more GATA3 than either the unvaccinated controls or the BCG Danish-vaccinated animals after infection. Animals were divided into pathology groups to correlate gene expression with severity of pathology. Animals in the visible lesion group expressed more Tbet and IFN-γ than animals that were culture negative, while Tbet and IFN-γ expression in the culture-positive, no-visible-lesion group was intermediate. GATA3 expression inversely correlated with pathology. Overall, expression of immune response genes correlated more closely with pathology than vaccination treatment.

scholarly journals Cell-Mediated Immune Response to Tuberculosis Antigens: Comparison of Skin Testing and Measurement of In Vitro Gamma Interferon Production in Whole-Blood Culture

2001 ◽  
Vol 8 (2) ◽  
pp. 339-345 ◽  
Author(s):  
Rohit K. Katial ◽  
Joyce Hershey ◽  
Tejashiri Purohit-Seth ◽  
John T. Belisle ◽  
Patrick J. Brennan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Culture Filtrate ◽  
Whole Blood ◽  
Skin Testing ◽  
Gamma Interferon ◽  
Delayed Type Hypersensitivity ◽  
Noninvasive Test ◽  
Soluble Cell ◽  
Ifn Γ

ABSTRACT Although delayed-type hypersensitivity skin testing with tuberculin purified protein derivative (PPD) is the standard for tuberculosis screening, its variability suggests the need for a more sensitive, noninvasive test. An in vitro whole-blood assay has been proposed as an alternative. Using health care worker volunteers, we confirmed the correlation between PPD skin test (PPD-ST) results (positive, induration of >15 mm) and a standardized gamma interferon (IFN-γ) assay, QuantiFERON-TB (Q-IFN), manufactured by CSL Biosciences in Australia, and we evaluated Mycobacterium tuberculosisculture subfractions as potential substitutes for PPD. Twenty healthy volunteers with positive PPD-ST results and 20 PPD-ST-negative controls were enrolled. Whole blood was cultured with human PPD antigens (HuPPD), Mycobacterium avium complex (MAC) PPD, phytohemagglutinin (PHA), and four M. tuberculosis culture subfractions: low-molecular-weight culture, filtrate, culture filtrate without lipoarabinomannan, soluble cell wall proteins, and cytosolic proteins, all developed from M. tuberculosis strain H37RV. Secretion of IFN-γ (expressed as international units per milliliter) was measured by an enzyme immunoassay. The PPD or subculture fraction response as a percentage of the PHA response was used to determine positivity. Sixteen of 20 PPD-ST-positive individuals were classified as M. tuberculosis positive by Q-IFN, and 1 was classified as MAC positive. Sixteen of 20 PPD-ST-negative individuals were M. tuberculosis negative by Q-IFN, 2 were MAC positive, and 2 were M. tuberculosis positive. The tuberculosis culture subfractions stimulated IFN-γ production in PPD-ST-positive volunteers, and significant differences could be seen between the two PPD-ST groups with all subfractions except soluble cell wall protein; however, the response was variable and no better than the Q-IFN PPD. The agreement between the Q-IFN test and the PPD-ST was good (Cohen's kappa = 0.73). The Q-IFN assay can be a useful tool in further studies of immune responses to M. tuberculosisantigens.

scholarly journals Use of Recombinant ESAT-6:CFP-10 Fusion Protein for Differentiation of Infections of Cattle by Mycobacterium bovis and by M. avium subsp. avium and M. avium subsp. paratuberculosis

2004 ◽  
Vol 11 (4) ◽  
pp. 729-735 ◽  
Author(s):  
W. R. Waters ◽  
B. J. Nonnecke ◽  
M. V. Palmer ◽  
S. Robbe-Austermann ◽  
J. P. Bannantine ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Fusion Protein ◽  
Mycobacterium Bovis ◽  
Mycobacterium Avium ◽  
Infected Cattle ◽  
Mycobacterial Species ◽  
Blood Leukocytes ◽  
Necrosis Factor Alpha ◽  
Ifn Γ

ABSTRACT Immunological diagnosis of Mycobacterium bovis infection of cattle is often confounded by cross-reactive responses resulting from exposure to other mycobacterial species, especially Mycobacterium avium. Early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) are dominant gamma interferon (IFN-γ)-inducing antigens of tuberculous mycobacteria, and they are absent from many environmental nontuberculous mycobacteria. Because M. avium exposure is the primary confounding factor in the diagnosis of M. bovis-infected animals, in vitro responses to a recombinant ESAT-6:CFP-10 (rESAT-6:CFP-10) fusion protein by blood leukocytes from cattle naturally exposed to M. avium or experimentally challenged with Mycobacterium avium subsp. avium or Mycobacterium avium subsp. paratuberculosis were compared to responses by M. bovis-infected cattle. Responses to heterogeneous mycobacterial antigens (i.e., purified protein derivatives [PPDs] and whole-cell sonicates [WCSs]) were also evaluated. Tumor necrosis factor alpha (TNF-α), IFN-γ, and nitric oxide responses by M. bovis-infected cattle to rESAT-6:CFP-10 exceeded (P < 0.05) the corresponding responses by cattle naturally sensitized to M. avium. Experimental infection with M. bovis, M. avium, or M. avium subsp. paratuberculosis induced significant (P < 0.05) IFN-γ and nitric oxide production to WCS and PPD antigens, regardless of the mycobacterial species used for the preparation of the antigen. Responses to homologous crude antigens generally exceeded responses to heterologous antigens. Nitric oxide and IFN-γ responses to rESAT-6:CFP-10 by blood leukocytes from M. bovis-infected calves exceeded (P < 0.05) the corresponding responses of noninfected, M. avium-infected, and M. avium subsp. paratuberculosis-infected calves. Despite the reported potential for secretion of immunogenic ESAT-6 and CFP-10 proteins by M. avium and M. avium subsp. paratuberculosis, it appears that use of the rESAT-6:CFP-10 fusion protein will be useful for the detection of tuberculous cattle in herds with pre-existing sensitization to M. avium and/or M. avium subsp. paratuberculosis.

scholarly journals Optimization of a Whole-Blood Gamma Interferon Assay for Detection of Mycobacterium bovis-Infected Cattle

2009 ◽  
Vol 16 (8) ◽  
pp. 1196-1202 ◽  
Author(s):  
Irene Schiller ◽  
W. Ray Waters ◽  
H. Martin Vordermeier ◽  
Brian Nonnecke ◽  
Michael Welsh ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Mycobacterium Bovis ◽  
Whole Blood ◽  
Intradermal Injection ◽  
Gamma Interferon ◽  
Blood Collection ◽  
Cell Mediated Immune Response ◽  
Delayed Initiation ◽  
Ifn Γ

ABSTRACT Antigens of Mycobacterium bovis elicit a cell-mediated immune response upon intradermal injection in cattle. In vitro, such antigens stimulate the production of gamma interferon (IFN-γ) by bovine T cells in whole-blood culture (IFN-γ assay). We have analyzed various parameters of the in vitro IFN-γ assay, ranging from blood sampling to execution of the IFN-γ test, in view of potential simplifications of the assay. Here, we show that IFN-γ responses may be reduced under certain animal handling/holding conditions and that a delayed time from blood collection to culture may lead to a reduced in vitro IFN-γ response. Delayed initiation of culture in a purified-protein-derivative-based assay (24 h compared to 8 h after blood collection), however, resulted in a significant improvement of specificity (97% compared to 85%), whereas there was only a modest reduction of sensitivity (from 96% to 90%), which was statistically not significant. Furthermore, we show that the stimulation temperature needs to be 33°C or higher; that carbon dioxide is not required for stimulation; and that various plate formats, ranging from 24 to 96 wells per plate, can be utilized. The produced IFN-γ is stable at 4°C for 28 days as well as after repeated freeze-thaw cycles. Thus, stimulation of samples may be initiated in the field without the need for a carbon dioxide source, and bovine IFN-γ is stable under various routine laboratory temperature scenarios. These findings demonstrate opportunities for improvements in the bovine IFN-γ test platform and flexibilities in test application.

scholarly journals Results of Multiple Diagnostic Tests forMycobacterium avium subsp. paratuberculosis in Patients with Inflammatory Bowel Disease and in Controls

2000 ◽  
Vol 38 (12) ◽  
pp. 4373-4381 ◽  
Author(s):  
Michael T. Collins ◽  
Gorm Lisby ◽  
Claus Moser ◽  
Debra Chicks ◽  
Steen Christensen ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Diagnostic Tests ◽  
Ex Vivo ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vitro Assay ◽  
Inflammatory Bowel ◽  
Ifn Γ

Mycobacterium avium subsp. paratuberculosishas been incriminated as a cause of Crohn's disease (CD); however, studies to date have been relatively small and generally only used a single diagnostic assay. The objective of the study was to reexamine the association of M. avium subsp.paratuberculosis and CD using multiple diagnostic tests. Five methods were used to detect M. avium subsp.paratuberculosis infections in 439 inflammatory bowel disease (IBD) patients and 324 control subjects in the United States and Denmark. Most assays were adaptations of diagnostic tests for this infection performed routinely on animals. PCR for IS900, a genetic element unique to M. avium subsp.paratuberculosis, was positive significantly more often on resected bowel and lymph node tissues from CD patients (19.0%) and ulcerative colitis (UC) patients (26.2%) than from controls (6.3%) (P < 0.05). Positive IS900 PCR results occurred more often in U.S. than in Danish IBD patients, 32.0 versus 13.3% (P = 0.025). The majority of Danish patients were bacillus Calmette-Guérin (Mycobacterium bovisBCG) vaccinated (CD, 77.5%; UC, 86.6%; controls, 83.0%) whereas none of the U.S. patients with IBD and only 2% of U.S. controls were vaccinated. Among Danish IBD patients, positive PCR findings were four times more common among subjects who were not BCG vaccinated (33.3%) than among BCG vaccinates (8.8%, P = 0.02). Culture of the same tissues tested by PCR using modified BACTEC 12B medium failed to grow M. avium subsp. paratuberculosisfrom patients or controls. U.S. CD patients had the highest serological evidence (enzyme-linked immunosorbent assay [ELISA] for serum antibodies) of M. avium subsp. paratuberculosisinfection (20.7% of patients positive) which was higher than for all UC patients studied (6.1%) or healthy controls (3.8%,P < 0.005). Among Danish patients alone, however, no significant differences in rates of ELISA-positive results among CD, UC, or control patients were found. For 181 study subjects, both IS900 PCR and ELISA were performed. Although 11 were ELISA positive and 36 were PCR positive, in no instance was a patient positive by both tests, suggesting that these states are mutually exclusive. Evaluation of cytokine-mediated immune responses of IBD patients was complicated by the influence of immunosuppressive therapy given most IBD patients. Gamma interferon (IFN-γ) release by peripheral blood leukocytes after M. avium purified protein derivative PPD antigen stimulation showed significantly lower responses in CD patients than in UC patients or controls in both U.S. (by ex vivo assay) and Danish (by in vitro assay) populations (P< 0.05). Interleukin-5 responses were not different among CD, UC, or control groups. Collectively, the PCR, ELISA, and IFN-γ tests forM. avium subsp. paratuberculosis together with the unexpected observation that BCG vaccination influenced M. avium subsp. paratuberculosis detection, lead us to conclude that M. avium subsp. paratuberculosis, or some similarly fastidious mycobacterial species, infects at least a subset of IBD patients. Whether the infection is primary (causal) or secondary, it may contribute to the etiopathogenesis of IBD.

scholarly journals Preliminary Evaluation of Whole-Blood Gamma Interferon Release for Clinical Assessment of Cellular Immunity in Patients with Active Coccidioidomycosis

2005 ◽  
Vol 12 (6) ◽  
pp. 700-704 ◽  
Author(s):  
Neil M. Ampel ◽  
Daniel K. Nelson ◽  
Suzette Chavez ◽  
Kathryn A. Naus ◽  
Amanda B. Herman ◽  
...  
Keyword(s):  
Cellular Immunity ◽  
Whole Blood ◽  
The United States ◽  
Gamma Interferon ◽  
Clinical Severity ◽  
Skin Tests ◽  
Delayed Type Hypersensitivity ◽  
Ifn Γ ◽  
Cellular Immune

ABSTRACT Assessment of the cellular immune response in coccidioidomycosis has epidemiologic and prognostic importance. Measurement of delayed-type hypersensitivity to skin testing has been used in the past to determine cellular immunity in coccidioidomycosis. However, no skin tests are currently available in the United States. Assay of gamma interferon (IFN-γ) release in whole blood in response to incubation with antigen has been used to assess cellular immunity in tuberculosis. We used a similar assay using the coccidioidal antigen preparation T27K to measure the in vitro cellular immune responses among a cohort of 69 subjects with active coccidioidomycosis. IFN-γ release was bimodal, with concentrations above and below 5 IU/ml. Using multivariate logistic regression, underlying disease and disseminated or chronic pulmonary coccidioidomycosis was significantly associated with the release of IFN-γ at a concentration of <5 IU/ml (P = 0.02 or 0.05, respectively). In addition, the release IFN-γ concentration was <5 IU/ml in all subjects with a clinical severity score of ≥6 (P = 0.02). The release IFN-γ concentration correlated with expression of CD69 on T lymphocytes in an in vitro assay using T27K as the antigen (Spearman's rho = 0.59; P < 0.01). These results suggest that the IFN-γ release assay with T27K as the antigen may be a useful clinical test for assessing cellular immunity in patients with active coccidioidomycosis.

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