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ABSTRACT: The IL-12p40/IL-12Rbeta1 and IFN-gammaR1/IFN-gammaR2/STAT1 signaling pathways are important for clearing intracellular bacteria. Genetic defects within these pathways are associated with increased susceptibility to intracellular pathogens. Among these, IL-12Rbeta1 deficiency is the most common defect and leads to infections with Salmonella and Mycobacterium spp. We report a child who presented with Cryptococcal osteomyelitis and history of disseminated Mycobacterial infection and recurrent Salmonella septicemia. Flow cytometry showed defective expression of IL-12Rbeta1. Mutation analysis revealed a novel compound heterozygous mutation of IL12RB1, c.625C>T, p.Q209X was found in exon 7 on the paternal allele and c.710delC, p.P237HfsX5 was found in exon 8 on the maternal allele. As these mutations each result in a stop codon before the last spliceable exon, the transcripts likely underwent nonsense mediated decay, leading to a lack of IL12Rbeta1 expression on the cell surface and eradicating signaling via the IL12 signaling pathway.
Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 03/2012; 30(1):79-82. · 0.65 Impact Factor
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ABSTRACT: Enumeration of CD4+ T-lymphocytes is important in the management of HIV. However, standard laboratory systems based on flow cytometry are expensive, complicated, and thus unavailable to most resource-limited settings where a low-cost and fully automated point-of-care CD4 testing system is required. In attempts to address this issue, a study was conducted to validate the Alere PIMA point-of-care CD4 test.
Duplicate values of the absolute number of CD4+ T-lymphocytes in 203 HIV-infected blood samples obtained using the PIMA system were compared with the two predicate single-platform FACSCount and the dual-platform FACSCan (Becton Dickinson Biosciences).
The overall absolute CD4+ T-lymphocyte count obtained using the PIMA system correlated highly with the FACSCount (r = 0.957; mean bias, -54.2 cells/μL; limit of agreement, -190.9 to +82.5 cells/μL) and the FACSCan (r = 0.957; mean bias -44.0 cells/μL; limit of agreement, -179.7 to +91.6 cells/μL). Good correlation and low biases were also observed for samples with CD4+ T-lymphocyte count ranges of 0 to 200 and 0 to 350 cells/μL. Additionally, there was no significant difference in absolute CD4+ T-lymphocyte counts noted between the duplicate samples using the PIMA system.
This new point-of-care product is a simple and reliable system and should contribute significantly to the simplification of performing CD4 testing and thus increase access for patients in resource-limited settings. The inability to obtain values for the frequency (%) of CD4+ T-lymphocyte count is one limitation of the PIMA system, the addition of which would be of value for clinical staging or monitoring in HIV-infected pediatric patients.
JAIDS Journal of Acquired Immune Deficiency Syndromes 06/2011; 58(2):141-7. · 4.43 Impact Factor
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ABSTRACT: The frequency and absolute number of CD4+ T-lymphocytes continue to be one of the major clinical markers for management of HIV/AIDS. The present standard dual-platform (DP) three-color and two-color PanLeucogating flow cytometric (FCM) methods for most developing countries are either expensive if manufacturers' monoclonal antibody reagents are used or limited due to an insufficient supply of generic reagents. Clearly, more affordable FCM methods are needed.
To develop a novel DP FCM method using biotin-streptavidin-fluorochrome labeling in combination with the two standard DP methods for 4 different white blood cells (WBC) using only one monoclonal antibody reagent.
The percentage of CD4+ T-lymphocytes in 116 HIV-infected blood samples was determined using our new method. Results were compared with the two standard methods. Correlation and agreement of the pair method were determined using linear regression, Bland-Altman and percent similarity analysis.
Our study showed that percentage of CD4+ T-lymphocyte values obtained from the new method correlated highly with the standard three-color and the two-color methods (r2 = 0.95 {n=52} and 0.97 {n=64}). The mean bias and percent similarity for the new method compared with the two standard methods were -0.53% (limit of agreement {LOA}:-5.22% to +4.16% with percent similarity of 99.28; and -0.22% with LOA of -3.42% to +2.98%, the percent similarity of 98.15, respectively.
Our FCM method using biotin to label 4 different WBC samples followed by streptavidin staining is reliable for determination of CD4+ T-lymphocytes. Such an approach will significantly reduce the cost for monitoring HIV-infected patients in resource-limited settings.
Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 06/2011; 29(2):190-9. · 0.65 Impact Factor
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ABSTRACT: Enumeration of CD4+ T lymphocytes is important in management of HIV-infected patients. However, CD4 testing by current gold standard bead-based flow cytometer (FCM) system is expensive for developing countries. This study compared 2 affordable volumetric FCMs with the 3 predicate FCM systems. CD4+ T-lymphocyte counts on blood samples from 150 HIV-1-infected Thai patients were determined in parallel by 5 FCM systems: the 2 single-platform volumetric FCM systems, Guava and CyFlow(green); the 2 standard single-platform bead-based systems (2-color FACSCount and the TriTEST/TruCOUNT tube using a FACSCalibur FCM); and the dual-platform TriTEST system. Correlation and agreement were analyzed using linear regression and Bland-Altman analysis. Results from these 2 volumetric systems gave similar results and excellent correlation: R2 > 0.93; mean biases ranged from +6.3 to +24.1 cells per microliter more for the Guava. In contrast, the CyFlow(green) showed the lowest values with R2 > 0.97; mean biases ranged from -9.8 to -27.6 cells per microliter. This indicates that the absolute CD4+ T-lymphocyte counts determined by CyFlow(green) are < FACSCount < DP TriTEST < TriTEST/TruCOUNT < Guava. Although the use of these 2 volumetric FCMs could make CD4+ T-lymphocyte enumeration more affordable in resource-poor settings, variations among these systems should be considered if these are to be interchanged.
JAIDS Journal of Acquired Immune Deficiency Syndromes 12/2008; 49(4):339-47. · 4.43 Impact Factor
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ABSTRACT: Absolute CD4+ T-lymphocyte counts are used in the initiation and monitoring of antiretroviral therapy in HIV-infected patients. Becton Dickinson's (BD) FACSCount system was introduced 12 years ago as a dedicated instrument for enumeration of absolute CD4+ T-lymphocytes. However, this system does not provide percent CD4+ T-lymphocyte that is the required monitoring parameter in pediatric patients. We evaluated a new BD FACSCount CD4 software and reagents for simultaneous percent and absolute CD4+ T-lymphocytes in HIV-infected blood.
Percent and absolute CD4+ T-lymphocytes in 149 HIV-infected blood samples were determined using a new FACSCount system. Results of percent and absolute CD4+ T-lymphocytes were compared between the dual-platform (DP) method, using BD FACScan flow cytometer plus hematology analyzer and the standard FACSCount system. Correlation and agreement were analyzed using linear regression and Bland-Altman analysis.
Percent CD4+ T-lymphocyte values obtained from the new FACSCount system correlated well with DP FACScan method (r2 = 0.977, P < 0.0001). Mean bias was only -0.36% [limit of agreement (LOA): -2.52% to +1.80%] and percent similarity was 101.36%. For absolute CD4+ T-lymphocyte, the new system correlated highly with standard FACSCount system (r2 = 0.986, P < 0.0001), with a percent similarity of 98.2. Mean bias was +3.39 cells/microl with LOA of -52.53 cells/mul to +59.31 cells/microl.
This new FACSCount system is a simple and reliable system for enumeration of absolute and percent CD4+ T-lymphocytes. Having one system giving both results should reduce the cost and thus increase access to CD4 testing for pediatric and adult patients.
Cytometry Part B Clinical Cytometry 01/2008; 74 Suppl 1:S98-106. · 2.53 Impact Factor
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ABSTRACT: We evaluated a boy who had multiple Salmonella septicemia, Aspergillus pneumonia and brain abscesses. His nitroblue tetrazolium (NBT) test was reportedly abnormal. The dihydrorhodamine (DHR) flow cytometry assay was compatible with typical X-linked chronic granulomatous disease (X-CGD). CYBB analysis revealed a novel complex mutation atggacg --> ttca in exon 12 (base pairs 1532-1538). As a result, 3 amino acids Tyr 511, Gly 512 and Arg 513 were deleted and replaced by 2 amino acids, Phe and Gln. The DHR and mutation analysis of his mother showed normal DHR pattern and no mutations in exon 12 of CYBB gene. In conclusion, any children with multiple Salmonella and Aspergillus infection should be suspected of CGD. NBT test, DHR assay and gene analysis are helpful toolsto confirm the diagnosis e v en i n the case of de novo mutation.
Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 12/2007; 25(4):249-52. · 0.65 Impact Factor
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Sureerat Pongpreuksa,
Orathai Jirapongsananuruk,
Deborah Noack,
Siribangon Boonchoo, Charin Thepthai,
Kulkanya Chokephaibulkit,
Nualanong Visitsunthorn,
Pakit Vichyanond,
Voravich Luangwedchakarn,
Surachai Likasitwattanakul,
Surapon Piboonpocanun
World Allergy Organization Journal 10/2007;
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ABSTRACT: Various assays are used to enumerate peripheral blood absolute CD4+ T-lymphocytes. Flow cytometry is considered the gold standard for this purpose. However, the high cost of available flow cytometers and monoclonal antibody reagents make it difficult to implement such methods in the resource-poor settings. In this study, we evaluated a cheaper, recently developed single-platform microcapillary cytometer for CD4+ T-lymphocyte enumeration, the personal cell analyzer (PCA), from Guava Technologies.
CD4+ and CD8+ T-lymphocyte counts in whole blood samples from 250 HIV-1 infected Thais were determined, using a two-color reagent kit and the Guava PCA, and compared with the results obtained with two reference microbead-based methods from Becton Dickinson Biosciences: the three-color TruCOUNT tube method and the two-color FACSCount method. Statistical correlations and agreements were determined using linear correlation and Bland-Altman analysis.
Absolute CD4+ T-lymphocyte counts obtained using the Guava PCA method highly correlated with those obtained using TruCOUNT method (R(2) = 0.95, mean bias +13.1 cells/microl, limit of agreement [LOA]-117.9 to +144.1 cells/microl) and the FACSCount method (R2 = 0.94, mean bias = +33.2 cells/microl, LOA-101.8 to +168.3 cells/microl). Absolute CD8+ T-lymphocyte counts obtained using the Guava PCA method also highly correlated with those obtained with the two reference methods (R(2) = 0.92 and 0.88, respectively).
This study shows that the enumeration of CD4+ T-lymphocytes using the Guava microcapillary cytometer PCA method performed well when compared with the two reference bead-based methods. However, like the two reference methods, this new method needs substantial technical expertise.
Cytometry Part B Clinical Cytometry 10/2007; 72(5):387-96. · 2.53 Impact Factor
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ABSTRACT: The current method of CD4 enumeration in Thailand, based on the three-tube, three-color method recommended by the Centers for Disease Control and Prevention, is expensive and thus unavailable to most patients who have the human immunodeficiency virus (HIV). Less expensive, simpler protocols (i.e., PanLeucogating and primary CD4 gating) have been described but require more published validation data to gain widespread acceptance. We describe a multicenter evaluation of the PanLeucogating method.
The PanLeucogating method using generic reagents was evaluated in comparison with the standard three-tube, three-color method using commercial reagents. Percentage of CD4+ T cells among lymphocytes and absolute CD4+ T-cell counts were determined in 611 HIV-infected individuals recruited from four sites. Linear regression and Bland-Altman tests were used for statistical analysis.
The correlation of percentage of CD4+ T cells and absolute CD4+ T-cell counts obtained with the PanLeucogating strategy and the standard predicate method was high (r2 = 0.96 and 0.95, respectively, for the entire study population and r2 > 0.95 and 0.93, respectively, for each study group). Absolute CD4+ T-cell counts of the overall study pool and of the two subdivisions of absolute CD4+ T-cell counts (i.e., 0-250 cells/microl and > 250 cells/microl) derived from the two methods demonstrated excellent agreement, with mean biases of +18 cells/microl, +11 cells/microl, and +24 cells/microl, respectively.
These observations demonstrate that CD4 enumeration by PanLeucogating is reliable and can be performed to an identical standard in a quality-assured network of collaborating laboratories as a new cost-effective approach to HIV monitoring.
Cytometry Part B Clinical Cytometry 05/2005; 65(1):29-36. · 2.53 Impact Factor
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ABSTRACT: In Thailand, over one million people have been infected with HIV since the beginning of the epidemic. This has created a great burden on the country's limited health care budget. Monitoring CD4+ T-lymphocytes is important to determine the success of any antiretroviral therapy as well as HIV vaccine trials. However, the high cost of CD4 counts makes monitoring of every HIV-infected patient impossible in Thailand. Therefore, the development of affordable strategies is necessary in order to allow more HIV infected persons to access CD4 testing to control the disease. The current standard methods for enumeration of CD4+ T-lymphocytes are performed on whole blood by flow cytometric immunophenotyping using the 6-tube 2-color and 3-tube 3-color panels recommended by the Centers for Diseases Control (CDC). In this study, percentage CD4+ T-lymphocyte values (from 142 HIV-seropositive patients and 26 anti-HIV negative adult blood donors) generated by the use of just 2 reagents (CD45/CD4) in a 1-tube 2-color panel employing side scatter/CD45 morphospectral gating were compared to those obtained by state of the art methods. We also compared the use of generic monoclonal antibody reagents with commercial reagents and found the results to be comparable with an overall correlation coefficient (r) of more than 0.95 for both CD4+ and CD8+ T-lymphocytes. Bland-Altman analysis of the mean CD4 values plotted against the difference in values between the generic reagents and the commercial reagents showed no bias. The 1-tube 2-color method using generic monoclonal antibody reagents potentially permits more affordable but reliable CD4 testing and therefore could increase access for more HIV-infected patients in resource-poor countries.
Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 07/2003; 21(2):105-13. · 0.65 Impact Factor
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ABSTRACT: Infection is very common in thalassemia and is one of the major causes of death. To date, it is not quite clear why these patients are susceptible to infection. In this study, lymphocyte immunophenotyping for CD3+ (T-cells), CD3+CD4+ (T-helper/inducer cells), CD3+CD8+ (T-suppressor/cytotoxic cells), CD3−CD19+ (B-cells), and CD3−CD16/56+ (natural killer cells) subsets and expression of the activation antigen CD69 on CD3+CD4+ and CD3+CD8+ T-cells were determined in the whole blood of thalassemia patients, using a three-color flow cytometric technique. Results showed that only splenectomized β-thalassemia/hemoglobin (Hb) E patients displayed a marked increase in absolute number of all lymphocytes. In addition, splenectomized β-thalassemia/Hb E showed a significantly lower percentage of CD3+ cells, with a corresponding increase in CD19+ cells. These differences, when compared with normal subjects and other thalassemia patients, may be attributed to splenectomy. -thalassemia patients, on the other hand, showed no significant difference from the normal group. While lymphocyte subsets in splenectomized β-thalassemia/Hb E patients showed an abnormal distribution, T-cell activation in these patients was not different from the activation seen in normal subjects. This implies that thalassemia patients, during the steady state of disease, appear to have normal T-lymphocyte function with only moderate abnormalities of T- and B-lymphocyte subsets.Cytometry (Comm. Clin. Cytometry) 42:11–17, 2000. © 2000 Wiley-Liss, Inc.
Cytometry 02/2000; 42(1):11 - 17.
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Voravich Luangwedchakarn,
Orathai Jirapongsaranuruk,
Julie E NiemeLa, Charin Thepthai,
Kulkanya Chokephaibulkit,
Sanya Sukpanichnant,
Punchama Pacharn,
Nualanong Visitsunthorn,
Pakit Vichyanond,
Surapon Piboonpocanun,
Thomas A Fleisher
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ABSTRACT: Genetic defects of interleukin (IL)-12/23-and interferon (IFN)-gamma-mediated immunity can cause increased susceptibility to intracellular microbes. Among these defects, a mutation of the gene encoding the IL-12 receptor beta1 (IL-12Rbeta1) is the most common worldwide. A 12-year old Thai boy with pre-existing neurofibromatosis type 1 (NF1) was evaluated for primary immunodeficiency after a history of tuberculous lymphadenitis, recurrent Salmonella infections and nocardiosis. Flow cytometry of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) revealed a defect in the IL-12Rbeta1 surface expression. A genetic study showed a novel nonsense homozygous mutation of the IL12RB1 gene in exon 4 (402C > A), confirming the diagnosis of IL-12Rbeta1 deficiency. This is the first case report of a primary IL-12Rbeta1 deficiency in Thailand with the interesting finding of a coexisting NF1.
Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 27(2-3):161-5. · 0.65 Impact Factor
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ABSTRACT: Burkholderia pseudomallei is the causative agent of melioidosis, a severe and potentially fatal infectious disease in humans known to be endemic in Southeast Asia and northern Australia. The infection is also increasingly recognized in various animal species with a potential to spread to humans. With the potential as a biological warfare agent, specific serodiagnosis of melioidosis for surveillance in large populations at risk, humans or animals, would be highly valuable. In this study, a competitive enzyme-linked immunosorbent assay (ELISA) using a lipopolysaccharide-specific monoclonal antibody was developed. The assay provides high specificity, based on a previously described monoclonal antibody to a specific epitope on the lipopolysaccharide (LPS) of B. pseudomallei. The assay sensitivity of 96.0% and specificity of 100% were achieved at a cutoff value of 50% inhibition in human culture-proven melioidosis cases. An optimal cutoff value of 65% inhibition for sera from a melioidosis endemic area was obtained by ROC analysis and resulted in an assay specificity of 86.2%, while maintaining assay sensitivity of 92.0%. A potential application of the assay in the serodiagnosis of melioidosis in animal species was also evaluated usina dolphin sera with satisfactory results.
Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 23(2-3):127-32. · 0.65 Impact Factor
