Introduction

Atopic dermatitis (AD) was first introduced in 1933 by Hill and Sulzberger in recognition of this close association between AD and respiratory allergy(₁). The concept that AD has an immunologic basis is supported by the observation that patients with primary T-cell immunodeficiency disorders are frequently associated with elevated serum IgE levels and eczematoid skin lesions indistinguishable from AD(₂). Cluster designation of monoclonal antibodies (cluster of differentiation (CD) designated from 1^st to 8^th workshops on international human leukocyte differentiation antigens with total number of (247) CDs(₃). Leukocytes express distinct assortments of molecules on their cell surfaces, many of which reflect either different stages of their lineage-specific differentiation or different states of activation or inactivation. Leukocyte cell surface molecules are routinely detected with anti- leukocyte monoclonal antibodies (mAbs). Using different combination of mAbs, it is possible to chart the cell surface immunophenotypes of different leukocyte subpopulations, including the functionally distinct mature lymphocyte subpopulations of B-cells, helper T-ells (TH), cytotoxic T-cells (Tc), and Natural Killer (NK) cells(₃). The dermal cellular infiltrate in AD mainly consists of CD₄ ⁺ and CD₈ ⁺ T-cells with a CD₄/CD₈ ratio similar to peripheral blood levels(₄). In recent studies, CD₈ ⁺ CLA⁺ T-cells in induction of immunoglobulin E (IgE) and prolonged eosinophil survival(₅).

The aim of the present study is evaluate/ or determine immunophenotyping of AD patients by measuring concentration of clusters of differentiation (CDs) in patients suffering from atopic dermatitis.

Materials and Methods

5 mls of venous blood were collected by aseptic venipuncture from (108) AD patients and the control group (100 healthy persons) in sterile glass tubes containing 10 IU/ml of sodium heparin or EDTA (anticoagulated tubes). All steps of CD marker procedure were carried according to instructions of supplied company (Bio source Int., Belgium)(₆,₇), that include three main steps:

1. Isolation of mononuclear (MN) cells (lymphocytes) by density gradient centrifugation using lymphoprep to give a lymphocyte concentration of 1-2 x10⁷ cell/ml.

2. Measuring the lymphocyte count and viability by trypan blue exclusion test. More than 95% of lymphocyte viability was ensured to perform the immunophenotyping analysis(₈).

3. Determine the specificity and concentration of known fluorescent monoclonal antibodies (McAbs) by immunoflorescence technique.

We used four McAbs in the present study :

Anti-CD₃-McAb Anti-CD₄-McAb Anti-CD₈-McAb Anti-CD₁₉-McAb

A reaction was considered positive when cells have multiple fluorescent dots on the membrane or homogenous bright green membrane fluorescence(₇).

Statistical analysis

Results

The mean of CDs concentration (CD₃, CD₄, CD₈ and CD₁₉) of AD patients are (82.2, 55.7, 28.7 and 21.9) % of + ve lymphocytes respectively while the means of CDs concentration of healthy / or control group are (74.2, 40.3, 18.5 and 13.1) % of +ve lymphocytes of above CDs respectively. Fig (1)

The concentration of CDs (CD3, CD4, CD8 and CD19) had a highly values or means than those for healthy/ or control group in (65.7%, 75.9%, 94.4% and 68.5%) of AD patient respectively with significant differences (P< 0.05).

The statistical similarity analysis of CDs illustrated that CD3, CD4 and CD8 had similarity ranged between 94-97%, and CD19 splitted from its in similarity ratio near 63.86%. Fig (2).

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Discussion

Our results showed a significant elevation of various types of studied CDs value, those results were compatible and confirmed by the results of other studies that evidenced correlation between various CDs and atopic dermatitis(₉,₁₀,₁₁,₁₂). While, there are many other studies interested in other CDs such as CD23, CD24, CD26, CD28, CD30, CD45,CD83, CD137 and CD153(₁₃,₁₄,₁₅,₁₆,₁₇).

The importance of study CDs and their reactions with atopic dermatitis is interrupt with CD functions and their affecting role in immunopathology of allergic and /or atopic diseases(₃). CD3 was associated with T-cell antigen receptor. Required for cell surface expression of and signal transduction by TCR, cytoplasmic domains contain ITAM motifs and bind Cytoplasmic tyrosine kinase(₁₈). CD4 is coreceptor for MHC class II molecules. Bind Lek on cytoplasmic face of membrane. Receptors for HIV-1 and HIV-2(₁₉). CD8 is coreceptor for MHC class I molecules. Binds Lek on cytoplasmic face of membrane(₂₀). And CD19 forms complex with CD21 (CR2) and CD81 (TAPA-1), coreceptor for B-cells-cytoplasmic domin. Binds cytoplasmic tyrosine kinases and PI-3 kinase(₂₁).

Conclusion

We conclude that there is an elevation of concentrations of all studied CDs of patients with atopic dermatitis in comparison with control / or healthy individuals.

Correspondence to

IHSAN EDAN AL-SAIMARY; Assist. Prof. Dept. Microbiology, Coll. Medicine, Univ. Basrah, PO BOX 696 Ashar, Basrah, IRAQ E-mail: Ihsanalsaimary@yahoo.com