أصل و خصائص الخلايا المذيلة في اللايشمانيا الجلدية

الملخص EN

Objective: Cutaneous leishmania attacks the epithelium and the derm.

It causes a dirty ulcer filled with cells and dead tissues, in addition to fluids and the defending cells represented by macrophages, leukocytes, lymphocytes and plasma cells.

The parasite components are also present.

Previously, all small monocytes taken from the leishmaniasis lesion and seen by the microscope were classified under the categories of lymphocytes or plasma cells.

The purpose of this work was to apply an intense microscopic study to the lymphocytes found in cutaneous leishmania and to reclassify them.

When a distinct cell is identified, the origin of this cell is to be defined and then, its role in cutaneous leishmania is to be declared.

Methods: The studied sample consisted of 50 patients, males and females infected with cutaneous leishmania.

In this study, microscopic slides were prepared from the secretion coming from the skin lesion and stained for the direct smear with wright stain.

As for the histological samples, they were stained with Heamatoxilin-Eosin (HE) stain and later, with LCA stain (which is an immuno-chemical stain specific for lymphocytes) and CD3 (an immuno-chemical stain specific for T-lymphocytes).

A comparative cytomorphologic study was conducted to those mononuclear cells presented with cytoplasmic protrusion, among the different preparations, with the different staining methods, in order to confirm any morphological similarities among those presented cells within the different preparations.

Microscopic photos were taken for results confirmation of those presumed cells.

Results: The study revealed that three cell types are present: the first is the classical lymphocytes, which were present in 50/50 of the specimens prepared.

The second was the plasma cells, though their concentration in the specimens was low when compared to the first type of cells; they were present in 50/50 cases of the prepared samples as well.

The third was the mononuclear cell, which looks like the lymphocytes with a cytoplasmic protrusion erupting out as a tail in shape.

The tail appeared in different length among those cells.

Those cells were present in 49/50 of the specimen studied.

The immunohistochemical stains for the lymphocytes in general (LCA), proved that both the normal lymphocytes and the monocytes with the cytoplasmic protrusion were present in the smear.

Both cells accepted the CD3 stain, which is a specific stain for T-lymphocytes.

Similarities in cytomorphology were recognized among the mononuclear cells (with tails) when stained by the different staining procedures.

Conclusions: In 98% of the studied cases, the existence of a new pattern of cells which look like lymphocytes with a cytoplasmic protrusion was proved.

This protrusion may increase in length, leading to a tail appearance.

These types of cells were positive for both the LCA and CD3 stains which are specific for the lymphocytes and the T-type of lymphocytes respectively.

This concludes that those cells -under study- are derived from the T-lymphocytes.