Normal values for the different classes of venous blood mononuclear cells defined by monoclonal antibodies

T cell subset profile in healthy Zambian adults at the University Teaching Hospital

Introduction

Symptom-free human immunodeficiency virus antibody-negative Zambian adults (51 subjects, aged 20 to 62 years, 33.3% women and 66.7% men) were studied to establish T cell subset reference ranges.

Methods

We carried out across sectional study at the University Teaching Hospital, Lusaka. Blood samples were collected from healthy donor volunteers from hospital health care staff, between February and March 2015. Immunopheno typing was undertaken to characterize Tcell subsets using the markers CD3, CD4, CD8, α4β7, Ki67, CD25, CCR7, CD54RA, CD57, CD28, CD27 and HLA-DR.

Results

Among 51 volunteers, Women had significantly higher absolute CD4 count (median 1042; IQR 864, 1270) than in men (671; 545, 899) (p=0.003). Women also had more CD4 cells expressing homing, naïve, effector and effector memory T cell subsets compared to men. However, in the CD8 population, only the effector cells were significantly different with women expressing more than the males.

Conclusion

We provide early reference range for T cell subsets in Zambian adults and conclude that among the African women some T cell subsets are higher than men.

Lymphocyte subset analyses in healthy adults vaccinated with yellow fever 17DD virus

In this study the kinetics of humoral and cellular immune responses in first-time vaccinees and re-vaccinees with the yellow fever 17DD vaccine virus was analyzed. Flow cytometric analyses were used to determine percentual values of T and B cells in parallel to the yellow fever neutralizing antibody production. All lymphocyte subsets analyzed were augmented around the 30th post vaccination day, both for first-time vaccinees and re-vaccinees. CD3+ T cells increased from 30.8% (SE +/- 4%) to 61.15% (SE +/- 4.2%), CD4+ T cells from 22.4% (SE +/- 3.6%) to 39.17% (SE +/- 2%) with 43% of these cells corresponding to CD4+CD45RO+ T cells, CD8+ T cells from 15.2% (SE +/- 2.9%) to 27% (SE +/- 3%) with 70% corresponding to CD8+CD45RO+ T cells in first-time vaccinees. In re-vaccinees, the CD3+ T cells increased from 50.7% (SE +/- 3%) to 80% (SE +/- 2.3%), CD4+ T cells from 24.9% (SE +/- 1.4%) to 40% (SE +/- 3%) presenting a percentage of 95% CD4+CD45RO+ T cells, CD8+ T cells from 19.7% (SE +/- 1.8%) to 25% (SE +/- 2%). Among CD8+CD38+ T cells there could be observed an increase from 15 to 41.6% in first-time vaccinees and 20.7 to 62.6% in re-vaccinees. Regarding neutralizing antibodies, the re-vaccinees presented high titers even before re-vaccination. The levels of neutralizing antibodies of first-time vaccinees were similar to those presented by re-vaccinees at day 30 after vaccination, indicating the success of primary vaccination. Our data provide a basis for further studies on immunological behavior of the YF 17DD vaccine.

Normal values of CD4 and CD8 lymphocyte subsets in healthy indian adults and the effects of sex, age, ethnicity, and smoking

BACKGROUND

Information on lymphocyte populations (T, B, and natural killer cells) and subpopulations (CD4 and CD8) in India is generally lacking. Measurement of T-cell subsets is important in India for evaluating disease stage and progression in individuals with the human immunodeficiency virus (HIV). Hence, this study was conducted to provide normal ranges of absolute and percentage values of CD4 and CD8 T-lymphocyte subsets and the ratio of CD4 to CD8 in normal Indian adults.

METHODS

Flow cytometric analysis (EPICS-XL) was used to determine the range of T-lymphocyte subpopulations in normal Indian blood donors at Command Hospital and the Armed Forces Medical College, Pune, India. The reference population consisted of 94 healthy HIV-seronegative blood donors. T-lymphocyte subsets were analyzed with two-color immunophenotyping of peripheral blood lymphocytes with the use of a lysed whole-blood technique and enumerated.

RESULTS

For normal values of various blood components, we found mean values of 2114 cells/microl for total lymphocytes, 865 cells/microl (40.2%) for CD4(+) lymphocytes, 552 cells/microl (31.3%) for CD8(+) lymphocytes, and 1.7 for the CD4:CD8 ratio. The 95% confidence intervals for the same parameters were 1115-4009 cells/microl, 430-1740 cells/microl (30.75-49.60%), 218-1396 cells/microl (20.06-42.52%), and 0.39-3.02 respectively. Females had significantly higher CD4 counts (P < 0.05), percentage of CD4 lymphocytes (P < 0.01), and CD4:CD8 ratio (P < 0.01). Males had a significantly higher percentage of CD8 lymphocytes (P < 0.01). They also had higher CD8 counts that did not reach significance. Age, ethnicity (Dravidian versus Aryan), smoking, alcohol consumption, and the interval between drawing the blood sample and its analysis were factors that did not produce statistically significant differences in the T-cell subsets studied.

CONCLUSIONS

When compared with other published series, the CD4 and CD8 values in healthy Indians were no different from those reported in the West. These observations have important clinical implications for the use of T-lymphocyte subset measurements in India, especially in the management of HIV infection. The normal ranges established by this study can be used as a reference for decisions made in clinical practice.

Two-colour immunoenzymatic technique using sequential staining by APAAP to evaluate two cell antigens

AIMS

To extend the alkaline phosphatase-antialkaline phosphatase (APAAP) immunoenzyme single stain method to a more generally applicable double stain technique. This will allow two primary antibodies of the same isotype of IgG and specifically the nuclear antigen bromodeoxyuridine (BRdU) to be evaluated with a cell surface antigen identifier.

METHOD

Sequential applications of the APAAP method showed two antigen sites by different dye couplings to a common alkaline phosphatase substrate, producing blue and red reaction products on the same slide. Antigens on different cell populations as well as those in different compartments of the same cell were analysed. The method allowed a surface antigen monoclonal to be revealed first, using an optimal fixative, before alcohol/gluteraldehyde fixation was used to start the second (BRdU) staining sequence.

RESULTS

An analysis of double staining of T lymphocyte subsets (CD4 and CD8) showed no significant difference in the order of application of the primaries (n = 10) and no significant difference from their corresponding single stain results (n = 50), confirming the validity of the technique where antigens are exclusively distributed. Other examples, including antigens distributed in different compartments of the same cell, displayed discrete staining which implied validity.

CONCLUSION

Double staining by APAAP with this technique seems to be applicable to those cases where antigens are exclusively distributed and includes cases where different compartments of the same cell are stained. It is especially useful in revealing antigens that require different fixation and preparation--that is DNA incorporated BRdU with a surface antigen. But it does seem to have a limited ability to produce a dual colour at a common site.

Nature of the mononuclear infiltrate and the mechanism of muscle damage in juvenile dermatomyositis and Duchenne muscular dystrophy

Normal skeletal muscle does not express class I MHC antigens. In contrast, these antigens are strongly expressed at the periphery of muscle fibres in patients with juvenile dermatomyositis (JDM) and Duchenne muscular dystrophy (DMD). Interferons can induce the expression of class I antigens, but in this study interferon-gamma could not be detected in JDM muscle biopsy specimens using four different immunocytochemical techniques. However, an infiltrate of mononuclear cells capable of synthesising interferons was present in biopsies from JDM and DMD patients. The predominant cell types detected in both diseases were macrophages and T lymphocytes, these two cell types comprising more than 80% of the infiltrating mononuclear cells. A striking predominance of CD4+ helper/inducer T cells was observed. The majority of these cells expressed class II MHC antigens and were, therefore, considered to be activated. Additional evidence for the functional activity of CD4+ T cells was derived from the finding that it was this population of cells from JDM biopsies which proliferated in response to interleukin-2 in vitro. T cell subsets in peripheral blood were also investigated in JDM and DMD patients. Only in the case of JDM were any significant differences from normal observed, where a significant reduction in the number of peripheral blood CD8+ T cells resulted in an elevation of CD4+/CD/8+ ratios. The role of CD4+ T cells and aberrant class I MHC antigen expression in mediating muscle damage in JDM and DMD is discussed.

Determination of lymphocyte subpopulations by enzyme immunoassay. Comparison with conventional fluorescence microscopy

An enzyme immunoassay for measuring lymphocyte subpopulations was evaluated and the results compared with those obtained with conventional fluorescence microscopy, using two different panels of antibodies. The enzyme immunoassay is a photometric method which expresses the results using a standard curve with known amounts of cells. The method was reproducible and accurate. The intra-assay variation for the standard curve ranged from 3.2 to 5.7% and the interassay variation from 9.5 to 13.8%. The intra-assay variation for clinical samples ranged from 3.3 to 8.2%. Results obtained with the enzyme immunoassay and with conventional fluorescence microscopy showed a significant correlation (P less than 0.05) for all the subclasses of lymphocytes tested using two different panels of monoclonal antibodies. We conclude that the choice of method should be related to the particular needs and manpower in the laboratory.

Mononuclear cell infiltration in central portions of human astrocytomas

The mononuclear cell infiltration in the central portion of human low- and high-grade astrocytomas has been examined using monoclonal antibodies to cell surface differentiation antigens. There was no significant difference between the number of T cells, B cells, or macrophages. The OKT8+ (suppressor/cytotoxic) T cell population was the major lymphocyte subset in the infiltrates. There was, however, indirect evidence for a proportion of the total OKT8+ cells being natural killer cells. Overall, there was a significant difference in the number of macrophages compared to the total lymphoid cell population. Several cell types seem to play an equal role in the cellular and humoral immune response within the center of the tumors, as distinct from that occurring at the periphery.

Impaired low-density lipoprotein receptor activity in chronic B-lymphocytic leukaemia cells

Cellular degradation of 125I-labelled low-density lipoprotein (LDL) was analysed in freshly isolated blood mononuclear cells from 26 patients with chronic B-lymphocytic leukaemia (CLL) and 8 healthy subjects, and in cells following 1, 2 and 3 d of culture in medium containing 10% human lipoprotein-deficient serum (LPDS). Fresh CLL cells had lower LDL degradation rates than mononuclear cells from healthy subjects (p less than 0.01). The LDL degradation rates increased during culture (p less than 0.001), but to a lesser degree in CLL cells than in normal blood mononuclear cells (p less than 0.001). The cellular degradation rate of 125I-LDL was markedly inhibited by an excess of unlabelled LDL, indicating that most of the 125I-LDL that was degraded had been internalized following binding to the high-affinity cell surface receptor. There was a positive correlation between the LPDS-induced LDL degradation of CLL cells and the thymidine uptake in CLL cell cultures with (r = 0.70, p less than 0.001) and without (r = 0.59, p less than 0.01) the B cell mitogen, Epstein-Barr virus. The results indicate that LDL receptors might be involved in the regulation of CLL cell proliferation.

Lymphocyte subsets and activation antigens in a reference population: a flow cytometric study using single and double antibody staining

The transferrin receptor (TR), the HLA DR antigen (DR), and the antigen binding OKT10 (T10) are present on activated lymphocyte populations. The authors have studied their expression and that of antigens defined by eight commercial monoclonal antibodies on peripheral blood lymphocytes of 50 healthy hospital workers aged 23-60 years. A whole blood lysis technique was employed and cells were enumerated on a flow cytometer. The percentage of cells bearing the three activation antigens were generally low: mean values for T10 being 7.2%; for TR 1.8%; and for DR 8.8%. There was, however, considerable variability, with occasional subjects having 20% or more cells positive for one of the three antigens. High values of one activation antigen did not correspond with high values of another in the same subject. Nor was there correlation of the presence of activation antigens with the occurrence of cells bearing T11, T4, T8, Leu 1, Leu 2a, Leu 3a, or Leu 7. Double labelling with the following pairs of fluorescein (FITC) and phycoerythrin (PE) labeled antibodies: Leu 2a, DR; Leu 3a, DR; Leu 3a, Leu 2a; TR, DR, indicated that simultaneous expression of the corresponding antigens do not normally occur on lymphocytes of healthy individuals. Double labelling with B1 and DR in five subjects indicated the presence of B1 (+) DR (-) cell population. No pattern of relationship could be detected among common clinical variables or HLA type and an increased expression of activation antigens.

Unusual myeloid leukaemia in patient with Hodgkin's disease

An unusual case of leukaemia in a patient with Hodgkin's disease is described. The leukaemic blast cell population was typified by the presence of a substantial proportion of binucleate and multinucleate cells, many of which had the morphological features of Sternberg-Reed cells. The circulating and bone marrow blast cells were shown by immunophenotyping to be of myeloid origin.

Lymphocyte surface marker studies in the diagnosis of unexplained lymphocytosis

Fifty-six patients with unexplained lymphocytosis were investigated with a panel of antibodies to lymphocyte surface antigens. In 23 the distribution of cell surface markers suggested reactive lymphocytosis. The remaining 33 patients showed a distribution of cell surface markers that indicated or suggested a diagnosis of B-cell lymphoproliferative disease. Two illustrative case reports show how such studies performed early in the investigation of unexplained lymphocytosis may permit earlier diagnosis of the underlying mechanism.

Lack of prognostic significance of T-lymphocyte subset counts in B-cell chronic lymphocytic leukaemia

In the 50 newly diagnosed, unselected, untreated B-CLL patients, the absolute numbers of blood T cells, T-helper cells, and T-suppressor/cytotoxic cells were by flow cytometric counting of mononuclear cells labelled with the monoclonal antibodies Leu5 (T cells), Leu3a (T-helper cells), and Leu2a (T-suppressor/cytotoxic cells). These estimations and the serum concentrations of IgG, IgA, and IgM were correlated to clinical stage (International Workshop System) and pretreatment observation time. For all patients together, the mean counts of Leu5+, Leu3+, and Leu2+ cells were significantly increased compared with the mean counts in 12 healthy controls (Mann-Whitney). In patients with advanced disease (stage B + C), both T-subset mean cell counts were significantly increased, whereas in patients with early-stage disease (stage A), although some high T-helper cell counts were noted, only the T-suppressor/cytotoxic mean cell count increase reached significance. Thus a trend was observed of a more frequent T-suppressor/cytotoxic cell predominance in early-stage disease, which is the opposite of the findings in most other prognostic studies. However, there was no significant difference in pre-treatment observation time according to T-helper: T-suppressor cell ratio below vs. above 1.0, irrespective of stage, whereas according to clinical stage, the pretreatment observation time in stage A was highly significantly longer than in stage B + C (logrank test). Thus, no independent prognostic significance of T-subset counts was found as judged by pretreatment observation time. No correlation was found between the occurrence of hypogammaglobulinaemia, T-subset ratios or T-subset counts.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful remission induction with deoxycoformycin in elderly patients with T-helper prolymphocytic leukaemia

Two elderly patients with prolymphocytic leukaemia (PLL) of T helper phenotype were treated with the adenosine deaminase inhibitor--deoxycoformycin--and achieved remission. The first patient has remained in an unmaintained remission for over a year. The second patient, treated with a regime which produced less side effects, subsequently relapsed in skin and lymph nodes and died. In view of the rarity of this condition a multi-centre assessment of the effectiveness of deoxycoformycin is indicated. T-lymphocyte colony formation in both cases was found to be reduced. Co-culture of the patients' lymphocytes with nonadherent mononuclear cells from normal individuals also showed inhibition of T-colony formation indicating that lack of nutrients or accessory cells was not responsible for low T-colony forming capacity.