scholarly journals Evaluation of a Low-Cost Strategy for Enumerating CD4 Lymphocyte Absolute Count and Percentage Using the FACSCalibur Flow Cytometer in HIV-Infected Patients from a Resource-Limited Setting

ISRN AIDS ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Gerardo Alvarez-Uria ◽  
Raghuprakash Reddy ◽  
Srinivasulu Reddy ◽  
Praveen K. Naik ◽  
Manoranjan Midde
Keyword(s):  
Flow Cytometer ◽  
Cd4 Cells ◽  
Absolute Count ◽  
Reduction Strategy ◽  
Resource Limited ◽  
Deming Regression ◽  
Facscalibur Flow Cytometer ◽  
The Cost ◽  
Cd4 Cell ◽  
Cd4 Lymphocytes

Enumeration of CD4 lymphocytes is essential for the clinical management of HIV-infected patients, but it can be difficult to afford in developing countries. In this study we evaluated a reagent reduction strategy for reducing the cost of enumerating CD4 cell absolute count and percentage using the FACSCalibur flow cytometer (Becton Dickinson). We compared the protocol recommended by the manufacturer with a protocol that used half of the usual amount of CD3/CD4/CD45 monoclonal antibody reagent in 100 samples from HIV-infected patients in a rural hospital in India. The concordance correlation coefficient between the two protocols was 0.976 for CD4 cell count and 0.984 for CD4 cell percentage. We did not find significant bias when performing Deming regression or Bland-Altman analysis. Sensitivity and specificity were 97% and 98.5% for identifying patients with less than 200 CD4 cells/μL, 98.1% and 93.8% for identifying patients with less than 350 CD4 cells/μL, and 100% and 94.7% for identifying patients with less than 25% CD4 cells, respectively. This reagent reduction strategy can be used for reducing the cost of enumerating CD4 lymphocytes in high-volume laboratories from resource-limited settings.

Proportion of IL-17A Producing CD4+ Cells Increases in Response to Alloreactivity as Part of a Network Involving Memory and Regulatory Cells Post HSCT.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1160-1160
Author(s):  
Andrzej Lange ◽  
Dorota Dlubek ◽  
Krzysztof Suchnicki ◽  
Sylwia Madej ◽  
Eliza Turlej
Keyword(s):  
Cell Population ◽  
Conflicts Of Interest ◽  
Disease Onset ◽  
Wilcoxon Test ◽  
Cd4 Cells ◽  
Similar Time ◽  
Ifn Gamma ◽  
Hematopoietic Stem ◽  
Cd4 Cell ◽  
Cd4 Lymphocytes

Abstract Abstract 1160 Poster Board I-182 Acute GvHD is a major factor affecting the outcome of hematopoietic stem cell transplantation (HSCT). In this study the focus was on the presence of IL-17-producing lymphocytes in patients post-HSCT with respect to FoxP3-positive lymphocytes and those with IFNgamma generation potential. The cytoplasmic expressions of IL-17, FoxP3, and IFN-gamma were studied in stimulated PBMCs (brefeldin A, Ionomycin, and PMA) of alloHSCT patients (43 patients, median age: 45 yrs, range; 1.0-64 yrs, with 41 hematological malignancies and 2 SCID).The cells were labeled with CD4, IL-17A, IFN-gamma, and FoxP3 MoAbs and analyzed in the CD4+ lymphocyte subpopulation. Twenty patients received MUD and 23 SIB transplants. Twenty developed aGvHD, among them 7 patients with aGvHD seen at a later stage after hematological reconstitution and 4 patients with recurrent clinical manifestation of aGvHD. It was found that: (1) the percentage of IL-17-producing CD4+ lymphocytes was higher in patients without aGvHD at the beginning of hematological reconstitution than in healthy controls (0.65±0.11% vs. 0.19±0.06%, p=0.02), (2) aGvHD cases with disease onset at the time of hematological reconstitution had lower proportions of IL-17A-producing CD4+ lymphocytes than those without aGvHD at a similar time after HSCT (0.31±0.1% vs. 0.65±0.11%, p=0.04), (3) when individual patients were followed it became apparent that the proportion of IL-17A-producing CD4+ lymphocytes, increased one week prior to aGvHD compared with the preceding observation (1.16±0.43% vs. 0.77±0.33%) and then a significant decrease was seen when symptoms became apparent (1.16±0.43% vs. 0.36±0.16%, p=0.017, Wilcoxon Test), (4) a high degree of correlation was found between the percentages of CD4+IL-17A+ and IFNgamma+CD4+ lymphocytes in blood at the time of hematological recovery (r=0.55, p=0.007), (5) patients with a higher percentage of IL-17A-producing cells in the CD4+ cell population more frequently had a higher proportion of FoxP3 in CD4+ cells (chi2=5.67, p=0.017), (6) the percentage of IFNgamma-producing CD4+ cells correlated with the proportion of FoxP3+ cells in the CD4+ cell population (r=0.48, p=0.02), and (7) the percentage of IL-17A-generating CD4+ cells rather inversely correlated with the proportion of CCR7+ lymphocytes in the blood of patients at the beginning of hematological recovery (r=-0.35, p=0.10). In conclusion Allogeneic HSCT induces the generation of IL-17A by CD4+ lymphocytes, especially in populations with lower proportions of naïve (CCR7+) lymphocytes, in response to alloantigens (the highest values were seen prior to the overt manifestation of aGvHD), which correlates with an increase in FoxP3+CD4+ cells. IL-17A-producing cells are likely to contribute to target organ lesions as they disappear from the blood at the time of overt manifestation of aGvHD. Supported by Grant no. 2P05E 037 30 from the Polish Ministry of Science & Higher Education. Disclosures No relevant conflicts of interest to declare.

scholarly journals Activation of CD4 cells by fibronectin and anti-CD3 antibody. A synergistic effect mediated by the VLA-5 fibronectin receptor complex.

1989 ◽  
Vol 170 (4) ◽  
pp. 1133-1148 ◽  
Author(s):  
T Matsuyama ◽  
A Yamada ◽  
J Kay ◽  
K M Yamada ◽  
S K Akiyama ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Synergistic Effect ◽  
Culture System ◽  
Receptor Complex ◽  
Cd4 Cells ◽  
Fibronectin Receptor ◽  
Serum Free ◽  
Cell Adhesive ◽  
Cd4 Cell ◽  
Cd4 Lymphocytes

In this study, fibronectin synergized with anti-CD3 antibody to promote CD4 cell proliferation in a serum-free culture system. The cell-adhesive domain plus additional regions of the fibronectin molecule are involved in this synergy. Anti4B4(CDw29) antibody blocked the activation of CD4 cells in this system. Furthermore, it is the VLA-5 protein within the set of molecules recognized by anti-4B4 that serves as a fibronectin receptor on the CD4 lymphocytes. The VLA-5 fibronectin receptor was mainly expressed on CD4+ CD45R-CDw29+ cells and may in part contribute to the unique function of these cells.

scholarly journals Modeling of the change in CD4 lymphocyte counts in patients before and after administration of the human immunodeficiency virus protease inhibitor indinavir.

1997 ◽  
Vol 41 (2) ◽  
pp. 449-453 ◽  
Author(s):  
D S Stein ◽  
G L Drusano
Keyword(s):  
Cell Count ◽  
Rate Constants ◽  
Half Life ◽  
Cd4 Cells ◽  
Cd4 Cell Count ◽  
Immunodeficiency Virus ◽  
The Mean ◽  
Cd4 Lymphocyte ◽  
Cd4 Cell ◽  
Cd4 Lymphocytes

We investigated the relationships between changes in CD4 lymphocytes counts over 24 weeks after the initiation of therapy with indinavir at dosages of > or = 2.4 g/day (n = 15) in human immunodeficiency virus-positive patients and compared them to the baseline values. Starting CD4 count were linked to the time-weighted average CD4 cell count (return) through a nonlinear effect model. The diminution of destruction of CD4 cells after the initiation of indinavir therapy was estimated by fitting simultaneous differential equations to the data by using a linked lymph node (LN)-blood (BL) (two-compartment) system in which there is a constant rate of generation (R), first-order transfer rate constants (KLN-BL and KBL-LN) of compartment exchange, and first-order rate constants of CD4 destruction in the absence and presence of indinavir (KLN-OUT1 and KLN-OUT2). The half-life of CD4 lymphocytes was calculated from the rate constants by standard two-compartment methods. The CD4 lymphocyte counts at the start and return were linked in a sigmoid-Emax model were the maximal effect (Emax) was at 574.6 cells/microliters and 50% of the effect occurred at 157.1 cells/microliters (r2 = 0.94; P < 0.001). The mean +/- standard deviation (median) KLN-OUT2 was 0.574 +/- 0.202 (0.589), indicating that indinavir decrease the destruction of CD4 cells by circa 41 to 42%. The mean (median) CD4 half-life was 11.5 +/- 5.72 day (10.3 days). In multivariate analysis, KLN-OUT2 was significantly correlated with starting the CD4 cells count and the change in the CD4 cell count on therapy. The relationship between CD4 lymphocyte half-life and the starting CD4 lymphocyte count was hyperbolic, with a rapid increase in half-life as the CD4 count decreased. On the basis of the calculated half-life, the average production (destruction) of CD4 lymphocytes was approximately 3 x 10(9) cells/day, with an individual variation of 44-fold. These findings suggest that (i) the CD4 lymphocyte cell count at the start is significantly correlated to both the decrease in the destruction rate of CD4 cells and the degree of change in the CD4 lymphocytes on therapy, (ii) the lower the initial CD4 lymphocyte count, the higher the amount of CD4 lymphocyte turnover and the lower the ability of the immune system to increase absolute CD4 lymphocyte levels after viral suppression, consistent with a decreased regenerative capacity with progression of disease; and (iii) the increase in CD4 lymphocytes is likely secondary to the expansion of proliferating pool of cells since our determinations are based on 24 weeks of effect.

scholarly journals A Population-Specific Optimized GeneXpert Pooling Algorithm for Chlamydia trachomatis and Neisseria gonorrhoeae To Reduce Cost of Molecular Sexually Transmitted Infection Screening in Resource-Limited Settings

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Sarah Connolly ◽  
William Kilembe ◽  
Mubiana Inambao ◽  
Ana-Maria Visoiu ◽  
Tyronza Sharkey ◽  
...  
Keyword(s):  
Trichomonas Vaginalis ◽  
Molecular Testing ◽  
Resource Limited Settings ◽  
Syphilis Infection ◽  
Syndromic Management ◽  
Sexually Transmitted ◽  
Factors Associated ◽  
Resource Limited ◽  
The Cost ◽  
Low Prevalence

ABSTRACT The sexually transmitted infections (STIs) chlamydia (CT) and gonorrhea (NG) are often asymptomatic in women and undetected by syndromic management, leading to complications such as pelvic inflammatory disease, infertility, and ectopic pregnancy. Molecular testing, such as the GeneXpert CT/NG assay, is highly sensitive, but cost restraints preclude implementation of these technologies in resource-limited settings. Pooled testing is one strategy to reduce the cost per sample, but the extent of savings depends on disease prevalence. The current study describes a pooling strategy based on identification of sociodemographic and laboratory factors associated with CT/NG prevalence in a high-risk cohort of Zambian female sex workers and single mothers conducted from 2016 to 2019. Factors associated with testing positive for CT/NG via logistic regression modeling included city, younger age, lower education, long-acting reversible contraception usage, Trichomonas vaginalis infection, bacterial vaginosis, and incident syphilis infection. Based on these factors, the study population was stratified into high-, intermediate-, and low-prevalence subgroups and tested accordingly—individually, pools of 3, or pools of 4, respectively. The cost per sample was reduced from $18 to as low as $9.43 in the low-prevalence subgroup. The checklist tool and pooling approach described can be used in a variety of treatment algorithms to lower the cost per sample and increase access to molecular STI screening. This is particularly valuable in resource-limited settings to detect and treat asymptomatic CT/NG infections missed by traditional syndromic management.

scholarly journals Effect of 2 Models of Care and Factors Predicting Patients’ Adherence to Doctor’s Appointment Attendance in Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria

2016 ◽  
Vol 16 (3) ◽  
pp. 296-302 ◽  
Author(s):  
Roseline Iberi Aderemi-Williams ◽  
Fola Tayo ◽  
Aba Sagoe ◽  
Mathew P. Zachariah
Keyword(s):  
Models Of Care ◽  
University Teaching ◽  
Adherence Rate ◽  
State University ◽  
Cd4 Cells ◽  
Model Of Care ◽  
Appointment Attendance ◽  
Drinking Habits ◽  
Resource Limited ◽  
Predictors Of Adherence

Background: Provision of antiretroviral therapy in resource limited settings has put pressure on the available infrastructure. Objectives: The study examined patients’ adherence to Doctor’s appointment attendance after an intervention changing the model of care and factors that predicted adherence. Methods: Observational study was carried out over four years. The model of care was changed in the last year and the effect assessed. SPSS version 15.0 was used for analysis. Predictors of adherence were determined using logistic regression model. Results: Over half 148 (59.7%) of the patients were females, with a mean age of 40.4±8.8 years and baseline CD4 cells of 143.5±92.7cells/microliters. “Adherence” rates were 51.3% in 2007, 35.9% in 2008 and 14.9% in 2009 giving patients’ average adherence to Doctor’s appointment attendance of 34.03%. Intervention changing the model of care in 2010 recorded an adherence rate of 93.1%. Conclusions: The change in model of care greatly improved patients’ “adherence”. Patients’ knowledge of management, adherence, and smoking and drinking habits were identified as statistically significant predictors of adherence.

scholarly journals Comparative evaluation of cost effective extraction free molecular technique for detection of SARS-CoV-2 with reference to standard VTM based RT-qPCR method

2021 ◽  
Author(s):  
Megh Singh Dhakad ◽  
Sanjib Gogoi ◽  
Ansu Kumari ◽  
Aashish Kumar Singh ◽  
Manoj B. Jais ◽  
...  
Keyword(s):  
Detection Method ◽  
Cost Effective ◽  
Molecular Technique ◽  
Rt Pcr ◽  
Index Method ◽  
Resource Limited ◽  
Qpcr Method ◽  
Kappa Value ◽  
The Cost ◽  
Higher Sensitivity

Background and Objectives: The entire globe is undergoing an unprecedented challenge of COVID-19. Considering the need of rapid and accurate diagnostic tests for SARS-CoV-2, this study was planned to evaluate the cost effective extraction free RT-PCR technique in comparison to the standard VTM based RT-qPCR method. Materials and Methods: Paired swabs from nasopharynx and oropharynx were collected for SARS-CoV-2 testing, from 211 adult patients (≥18 years) in VTM and plain sterile tubes (dry swabs). These samples were processed and RT-qPCR was carried out as per standard protocols. Results: 54.5% of the patients were females and 45.5% were males with sex ratio 1:1.19 (M: F). 38.86% were symptomatic, of which fever (86.59%), cough (79.23%) and breathlessness (46.34%) were the most common symptoms. The positivity by VTM based method and index method was 31.27% and 13.27% respectively. Of the 27 inconclusive results from index method, 37.04% were positive, 48.15% were negative by VTM based method. However, in 40 inconclusive results by VTM based method, 90% were negative and rest remained inconclusive by index method. The sensitivity and specificity of the index method were 39.39% and 85.71% respectively. The overall agreement between VTM based method and index method was 49.59% with estimated Kappa value of 0.19. Conclusion: VTM based method showed higher sensitivity compared to the index method. The higher positivity by VTM based method, suggests that VTM based method could plausibly be a better detection method of SARS-CoV-2. Still, the index method might add value in a resource limited setups for detection of SARS-CoV-2.  

scholarly journals Fast sorting of CD4+ T cells from whole blood using glass microbubbles

TECHNOLOGY ◽  
2015 ◽  
Vol 03 (01) ◽  
pp. 38-44 ◽  
Author(s):  
Chia-Hsien Hsu ◽  
Chihchen Chen ◽  
Daniel Irimia ◽  
Mehmet Toner
Keyword(s):  
T Cells ◽  
T Lymphocyte ◽  
Whole Blood ◽  
Specific Binding ◽  
Target Cells ◽  
Cd4 Cells ◽  
Specific Antibodies ◽  
Resource Limited ◽  
Aids Diagnosis ◽  
Better Than

The isolation of CD4 positive T lymphocyte (CD4+) from peripheral blood is important for monitoring patients after HIV infection. Here, we demonstrate a fast isolation strategy for CD4+ cells that involves mixing blood and glass microbubbles. After the specific binding of target cells to the microbubbles carrying specific antibodies on their surface, target cells will spontaneously float to the top of the blood vial and can be quickly separated. Using this strategy, we demonstrate that the isolation of CD4+ cells in less than 5 minutes and with better than 90% efficiency. This strategy for cell isolation based on buoyancy and glass microbubbles is quick and inexpensive, minimizes blood handling, does not require magnetic fields, or centrifugation equipment, and could lead to new, efficient strategies for AIDS diagnosis in resource-limited areas.

scholarly journals IS IT SAFE AND COST SAVING TO DEFER THE CD4+ CELL COUNT MONITORING IN STABLE PATIENTS ON ART WITH MORE THAN 350 OR 500 CELLS/µL?

2019 ◽  
Vol 11 (1) ◽  
pp. e2019063
Author(s):  
Benedetto Maurizio Celesia ◽  
Andrea Marino ◽  
Rosa Fontana del Vecchio ◽  
Roberto Bruno ◽  
Filippo Palermo ◽  
...  
Keyword(s):  
Cell Count ◽  
Mean Value ◽  
Cd4 Count ◽  
Cd4 Cells ◽  
Cd4 Cell Count ◽  
The Third ◽  
Cd4 Lymphocyte ◽  
Mean Cost ◽  
Cd4 Cell

Background CD4 lymphocyte cell count represents the main immunological marker used to monitor HIV infection. However, frequent monitoring may be unnecessary, could cause anxiety to the patient as well as burdening healthcare with extra expenses.   Objectives and methods To analyse the probability of maintaining a safe number of CD4 in HIV-positive subjects under treatment with ≥350 cells/µl at baseline during a three-year follow up. We conducted a retrospective study performing three analyses with Kaplan-Meyer method considering: 1) all patients independently from their viral load (VL); 2) patients with 500 > CD4 ≥ 350 cells/µl versus (vs) CD4 ≥ 500 cells/µl at baseline; 3) patients with VL < 20 copies/ml vs VL > 20 copies/ml.   Results 253 subjects were enrolled. The median CD4 count was 623 (489-805) cells/µl. Subjects maintaining ≥ 350 cells/µl in the first, second and third year were respectively 238 (94.1%), 229 (90.5%) and 226 (89.3%), independently from VL. Within subjects with ≥ 350 CD4/µl vs ≥ 500 CD4/µl at baseline, those who maintained ≥ 350 cells/µl until the third year were respectively 241 (95.3%) and 158 (98.1%). The probability of maintaining these values in the third year was 89.3% for those who had CD4 ≥ 350/µl at baseline and 98.1% for those who had CD4 ≥ 500/µl. This probability was around 90% vs 99% for subjects with HIV-RNA above or below 20 copies/ml. Secondly, we tried to estimate the costs of CD4 determinations in a three-year period (from April 1, 2013 to March 31, 2016). We analysed respectively 343 subjects in the first period, 364 in the second and 383 in the third, with a median value of 500 CD4/µl during the research time taken into account. We found a mean value of about two determinations patient/year (2.41 in 2013/2014; 2.32 in 2014/2015; 2.18 in 2015/2016), with a significant decrease between the first and the last period (p<0.001). The mean cost patient/year was €101.51 in the first year, €97.61 in the second, €92.00 in the third (p<0,001). Assuming to extend these procedures to all our patients with stable CD4 cells/µl and monitoring CD4 cell count once in a year, it could be possible to obtain an overall saving of €19,152/year.   Conclusions A very high percentage of subjects maintained a high and safe number of CD4 cells (>350 cells/µl) during a three-year follow up. It could be possible to save up to 66% of the costs by reducing the number of CD4 count determinations in a year, to have other favourable consequences as well, releasing new resources for patient’s management.

scholarly journals Mitochondrial Ca2+ and membrane potential, an alternative pathway for Interleukin 6 to regulate CD4 cell effector function

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Rui Yang ◽  
Dario Lirussi ◽  
Tina M Thornton ◽  
Dawn M Jelley-Gibbs ◽  
Sean A Diehl ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Inflammatory Diseases ◽  
Alternative Pathway ◽  
Effector Function ◽  
Cd4 Cells ◽  
Cd4 Cell ◽  
Cell Effector Function ◽  
Cell Effector

IL-6 plays an important role in determining the fate of effector CD4 cells and the cytokines that these cells produce. Here we identify a novel molecular mechanism by which IL-6 regulates CD4 cell effector function. We show that IL-6-dependent signal facilitates the formation of mitochondrial respiratory chain supercomplexes to sustain high mitochondrial membrane potential late during activation of CD4 cells. Mitochondrial hyperpolarization caused by IL-6 is uncoupled from the production of ATP by oxidative phosphorylation. However, it is a mechanism to raise the levels of mitochondrial Ca2+ late during activation of CD4 cells. Increased levels of mitochondrial Ca2+ in the presence of IL-6 are used to prolong Il4 and Il21 expression in effector CD4 cells. Thus, the effect of IL-6 on mitochondrial membrane potential and mitochondrial Ca2+ is an alternative pathway by which IL-6 regulates effector function of CD4 cells and it could contribute to the pathogenesis of inflammatory diseases.

scholarly journals Assessing the Potential Deployment of Biosensors for Point-of-Care Diagnostics in Developing Countries: Technological, Economic and Regulatory Aspects

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 119 ◽  
Author(s):  
Daniel Migliozzi ◽  
Thomas Guibentif
Keyword(s):  
Developing Countries ◽  
Technological Development ◽  
Point Of Care ◽  
Medical Personnel ◽  
Developed Countries ◽  
Key Factors ◽  
Resource Limited ◽  
Point Of Care Diagnostics ◽  
Successful Case ◽  
The Cost

Infectious diseases and antimicrobial resistance are major burdens in developing countries, where very specific conditions impede the deployment of established medical infrastructures. Since biosensing devices are nowadays very common in developed countries, particularly in the field of diagnostics, they are at a stage of maturity at which other potential outcomes can be explored, especially on their possibilities for multiplexing and automation to reduce the time-to-results. However, the translation is far from being trivial. In order to understand the factors and barriers that can facilitate or hinder the application of biosensors in resource-limited settings, we analyze the context from several angles. First, the technology of the devices themselves has to be rethought to take into account the specific needs and the available means of these countries. For this, we describe the partition of a biosensor into its functional shells, which define the information flow from the analyte to the end-user, and by following this partition we assess the strengths and weaknesses of biosensing devices in view of their specific technological development and challenging deployment in low-resource environments. Then, we discuss the problem of cost reduction by pointing out transversal factors, such as throughput and cost of mistreatment, that need to be re-considered when analyzing the cost-effectiveness of biosensing devices. Beyond the technical landscape, the compliance with regulations is also a major aspect that is described with its link to the validation of the devices and to the acceptance from the local medical personnel. Finally, to learn from a successful case, we analyze a breakthrough inexpensive biosensor that is showing high potential with respect to many of the described aspects. We conclude by mentioning both some transversal benefits of deploying biosensors in developing countries, and the key factors that can drive such applications.

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