Absolute CD4 T-lymphocyte Counts Research Articles

Idiopathic CD4 Lymphocytopenia Manifesting as Refractory Genital Dysplasia

Idiopathic CD4 lymphocytopenia is an immunodeficiency disorder with low absolute CD4 T-lymphocyte count with no evidence of human immunodeficiency virus or other known cause. A 22-year-old woman presented with a high-grade Pap test result. Work-up demonstrated cervical intraepithelial neoplasia 3 and vaginal intraepithelial neoplasia 3 with extensive condyloma. She presented 6 months after her initial treatment with recurrent disease and was referred to the immunology department, where she was found to have profound lymphopenia. After further evaluation, idiopathic CD4 lymphocytopenia was diagnosed. Idiopathic CD4 lymphocytopenia is a rare acquired immunodeficiency. Although genital dysplasia is common in young women, this case demonstrates the importance of determining other etiologies of recurrent human papillomavirus infections and possible immunodeficiencies that may affect management and outcomes.

LettersResponse From the Authors

I read with great interest the recent publication by Nantakomol and colleagues, Affordable Technology for Enumeration of the Absolute CD4 T-Lymphocyte Count by Cell Bead Assay .1 The title and content of this publication appear very similar to a previously published article by many of these same authors.2 Moreover, if the principal difference between these two publications is the emphasis on the …

Affordable Technology for Enumeration of the Absolute CD4 T-Lymphocyte Count by Cell Bead Assay

The quantitative BD Trucount (San Jose, CA) tube method is the conventional but expensive method to quantitate CD4+T-lymphocyte (CD4) counts, and this may be beyond the means of countries with limited resources. In this study, we validated a quantitative method known as a cell-bead (CB) assay to quantitate CD4 counts in the peripheral blood of healthy subjects. The absolute CD4 count obtained from the CB method was highly correlated with those obtained from the Trucount tube ( r2 =0.98, y = 26.73 +1.01x, P <0.0001 and a mean bias of 34.8 cell/μL, limit of agreement [LOA] −34.8-104.4 cell/μL) and flow rate-based assay method ( r2 = 0.97; y =69.51 + 0.88x, P <0.0001 and a mean bias −53.5 cell/μL, LOA −149.4-42.3 cell/μL). This study demonstrates that the CB method is suitable and more affordable for CD4 quantitation. This method is inexpensive and interchangeable with the latex bead-based methods for generating absolute counts in resource-limited areas. * CB : cell-bead LOA : limit of agreement FCM : flow cytometry DP : dual-platform SP : single-platform WBC : white blood cell FR : flow rate-based calibration RBCs : red blood cells MP : microparticles EDTA : ethylene diamine tetraacetic acid FITC : fluorescein isothiocyanate PE : phycoerythrin PerCP : peridinin chlorophyll protein FSC-H : forward scatter SSC-H : side scatter CV : coefficient of variation SD : standard deviation

Enumeration of the absolute CD4 T‐lymphocyte count by cell‐bead assay

We have previously developed an alternative approach for undertaking absolute cell counting based upon flow-rate calibration using cell bead (FCB), in which cell bead (CB) can be used as a flow-rate calibration material for generating the absolute microparticle counts. Here, we extended our work of counting CD4+ T-lymphocytes in HIV-infected blood samples with the FCB method. CD4+ T-lymphocyte counts in EDTA blood samples from 30 healthy subjects and 80 HIV-1-infected patients were determined using TriTEST reagent. The absolute CD4+ T-lymphocytes were measured by FCB, and the results were compared with the absolute counting by commercial latex bead (CLB) or with flow rate-based calibration method (FR). Statistical correlation and agreement were analyzed using linear regression and Bland-Altman analysis. There was no significant difference in the absolute number of CD4+ T-lymphocyte counts enumerated by FCB when compared with those two reference methods (CLB and FR). The absolute CD4+ T-lymphocyte counts obtained from FCB method was highly correlated with those obtained from CLB [r(2)= 0.99, y = 1.04x - 12.37, P < 0.001, and mean bias 11.96 cell/microl, limit of agreement (LOA) -57.82 - 81.74 cell/microl], FR method (r(2) = 0.98; y = 0.97x - 3.13, P < 0.001, and mean bias -24.15 cell/microl, LOA -114.44 - 66.13 cell/microl). The use of FCB is comparable with the use of CLB and FR. This approach showed the effective in reducing cost for generating the absolute CD4+ T-lymphocyte counts. Such an approach should facilitate and ensure the success of the ongoing antiretroviral therapy program in resource-limited countries.

Serial CD4 and CD8 T-lymphocyte counts and associated mortality in an HIV-2-infected population in Guinea-Bissau.

In an urban community in Guinea-Bissau, we followed a cohort of human immunodeficiency virus type 2 (HIV-2) seropositive individuals (N = 47) and seronegative controls (N = 82). T-lymphocyte subset determinations were done in 1988, 1990, and 1992. Serial determinations of CD4 percentages, CD8 percentages, and CD4/CD8 ratios for the same individual were stable for 31 seropositive and 51 seronegative individuals with repeated measurements. We found no significant differences in the changes during a 2- or 4-year period in CD4 percentages, CD8 percentages, absolute CD8 T-lymphocyte counts, CD4/CD8 ratio, white blood cell counts, lymphocyte percentages, and absolute lymphocyte counts for HIV-2-seropositive compared with HIV-2-seronegative individuals. Only absolute CD4 T-lymphocyte counts changed more for the HIV-2-seropositive than for HIV-2-seronegative individuals (p = 0.037). HIV-2-infected individuals who lived with an HIV-2-infected spouse had a lower CD4/CD8 ratio and had higher mortality than HIV-2 infected individuals who lived with an uninfected spouse. However, there were no significant differences in immunological and hematological values for the 8 HIV-2 seropositive individuals who died and the 39 who survived in the 8-year follow-up period. In conclusion, progression of immunosuppression in HIV-2 infection seems to be slower than in HIV-1 infection and may not be inevitable in all individuals.

Pancreatitis in pediatric human immunodeficiency virus infection

Because pancreatitis has been reported frequently in adults with human immunodeficiency virus infection, we sought to determine the incidence of pancreatitis in children with acquired immunodeficiency syndrome by reviewing all records of children with AIDS, their serum amylase and lipase levels, and the factors associated with pancreatitis through a case-control analysis. During a 6-year period pancreatitis developed in 9 (17%) of 53 pediatric patients with AIDS. Six children had vertical transmission of infection and three patients had acquired HIV infection through contaminated blood products. Pancreatitis developed at a median age of 5.2 years (range 1.2 to 20 years). All patients had vomiting and abdominal pain. When the patients were first seen, lipase values were elevated more than amylase values (p = 0.028). Amylase and lipase levels declined at comparable rates. In the case-control analysis, pentamidine isethionate was significantly associated with pancreatitis (p = 0.02); the risk was greater in patients who received pentamidine isethionate and had absolute CD4 T-lymphocyte counts less than 100 cells/mm3 (p = 0.001). Infections associated with the onset of pancreatitis included cytomegalovirus (4), Cryptosporidium (1), Pneumocystis carinii pneumonia (3), and Mycobacterium avium intracellulare (1). Coinfection with cytomegalovirus was associated with a protracted course in four children. Ultrasonographic examination demonstrated biliary ductal dilatation 6 months after the onset of pancreatitis in one child. Seven children have died at a mean of 8 months after the initial onset of pancreatitis; the one living child has survived 5 months from the onset of pancreatitis. We conclude that pancreatitis is common in pediatric patients with AIDS and may be related to pentamidine isethionate exposure, especially when absolute CD4 T-lymphocyte counts are less than 100 cells/mm3. Serum amylase levels do not always accurately predict the onset of pancreatitis; serum lipase levels should be measured in children with symptoms. The onset of pancreatitis in an HIV-infected child is a poor prognostic indicator.