Atopic dermatitis and the immune system

Currently, atopic dermatitis (AD) is considered as a multifactorial process, which is characterized by a number of clinical, anatomical, physiological and pharmacological abnormalities. It is believed that atopic dermatitis is a form of immune deficiency, manifested by dysfunction of cellular-humoral immunity factors. However, the data obtained are quite contradictory. Various variants of dysgammaglobulinemia have been identified, more often expressed in an increase in the level of various immunoglobulins. However, D. I. Grove et al (1975) noted a high prevalence of atopy in immunoglobulin E deficiency syndromes. Immunoglobulin deficiency was established in 7% of patients.

The average percentage of T-lymphocytes in patients (AD) was significantly lower, and the average values ​​of B-lymphocytes were almost the same as in the control group. A decrease in the level of T-lymphocytes in atopic dermatitis is a constant symptom, independent of the clinical condition or the concentration of IgE in the blood serum [5].

It has been shown that 85% of children whose serum IgE level was elevated at birth developed allergic and presumably allergic diseases during the first 6 years of life [2]. It is possible that the increased risk of developing an allergic disease is associated with an inborn defect in the ability of T cells to induce IgE suppression. Indeed, all authors emphasize an increase in the level of IgE in patients (AD) [1, 4]. G. C. Maize (1976) notes that the decrease in the number of T cells is inversely proportional to the level of IgE in serum, which indicates a violation in the functional state of cell-mediated immunity.

For the treatment of AD, various drugs are used that act on the pathogenetic mechanisms of its occurrence. These include corticosteroids, antipruritics, tranquilizers, specific hyposensitization drugs, as well as drugs that affect T-cell immunity. As immunomodulators try to use levamisole, transfer factor, thymosin, thymopoietin [3].
For the treatment of patients with atopic dermatitis, we used vilozen, a lyophilized extract of the thymus gland, which is a dialyzable factor of the gland, obtained at the Kiev Research Institute of Endocrinology and Metabolism. The molecular weight of the ingredients included in the preparation does not exceed 992.1 a. e. m. (1000 daltons). The introduction of dialysable thymus factor to sensitized animals reduces the formation of IgE reagins (IA Bezvershenko et al., 1979).

The immunological status of patients was assessed by determining the main classes of immunoglobulins (G, M, and A) using immunodiffusion techniques; the reaction of blast transformation of lymphocytes (RBTL) with phytohemagglutinin, using the method of G. Bach and co-authors (1969) in the micromodification proposed by M. P. Grigoriev and I. I. Kopelyan (1972); the percentage of T- and B-lymphocytes (E-ROK and EAC-ROK) – according to I. Scand; the amount of circulating immune complexes (CIC) was determined by differential precipitation in polyethylene glycol. The IgE level was determined by radioimmunoassay using the commercial kit “Phadebas IgE PRIST” manufactured by “Pharmacia Diagn”. (Sweden).

We observed 77 patients (AD) of both sexes aged 5 to 30 years. The duration of the disease in 12 patients was from 1 to 5 years, in 47 – from 6 to 20 years, in 18 patients – over 20 years. Food allergy was noted in 26 patients, household – in 1. Concomitant diseases, mainly from the digestive system, were detected in 25 patients. The combination of skin and respiratory (bronchial asthma, vasomotor rhinitis) atopy was observed in only 8 patients. Various atopic diseases in the family were found in 37.6% of patients.

In 44 patients, an erythematosio-squamous form of atopic dermatitis with lichenification was observed. The skin pathological process was localized in the area of ​​the elbows, popliteal fossae, on the neck and back of the hands. The skin in the foci is hyperemic, dry, lichenified, with small lichenoid papules, abundant fine-lamellar and pityriasis peeling. The lichenoid form was in 30 patients, it was expressed by diffuse hyperemia, dryness, lichenification, edema, the presence of lichenoid papules along the periphery, pityriasis peeling. Excruciating itching led to many pinpoint excoriations. The process was localized on the skin of the trunk, limbs, face, sometimes exacerbation led to generalization of the lesion, up to erythroderma. A prurigo-like form, mainly on the extensor surfaces of the extremities, was noted in 2 patients, and an erythematous-squamous form with localization on the cheeks was observed in 1 patient.

All patients in the past were repeatedly treated with the use of antihistamines, corticosteroids, non-specific desensitization, external agents. Many received spa treatment.

Vilozen patients received intranasally for 14 days in the form of an aqueous solution.

The control group consisted of 20 healthy individuals. Before treatment, certain changes in the immunological status were revealed in patients with atopic dermatitis. Thus, the E-ROCK indicator was significantly reduced – 37.51% ± 1.99% at a norm of 52% ± 1.8% (P<0.01), and the EAC-ROCK did not have a significant difference and amounted to 25.88% ± 1.44% compared with the control – 22.1% ± 1.4% (P>0.05). Consequently, the number of thymus-dependent leukocytes turned out to be reduced.

One of the methods for assessing immunological reactivity is the study of RBTL, which reflects the ability of cells to proliferate when the PHA mitogen is introduced into the culture of lymphocytes. The patients examined by us showed an increased response to a nonspecific mitogen — 66.68% ± 1.31% at a rate of 58.2% ± 2.6% (P<0.05). The height of power transformation is probably due to the intensity of both cellular and humoral immunity or is associated with the presence of biologically active substances, which themselves may have mitogenic properties. Normally, CECs are removed from the bloodstream by phagocytosis. Meanwhile, with a decrease in the activity of the lymphoid-macrophage system, the CECs are fixed in the body. The level of CEC (0.153 g/l ± 0.005 g/l) in the blood serum of patients significantly exceeded that of healthy people (0.067 g/l ± 0.02 g/l; P<0.01). Before treatment, a deficiency of IgA, IgM, IgG — 1.27 g/l ± 0.06 g/l; 0.95 g/l ± 0.12 g/l; 10.58 g/l ± 0.38 g/l vs. 2.06 g/l ± 0.17 g/l: 1.18 g/l ± 0.014 g/l; 17.85 g/l ± 0.97 g/l is normal. This fact indicates a violation in the humoral (in the cellular) link of the immune system. Meanwhile, the level of IgE was almost three times higher (50.29 cu/l ± 76 cu/l) than in healthy individuals (18.32 cu/l ± 5.19 cu/l at P<0.01). At the same time, a correlation was observed between the severity of the disease, an increased amount of IgE and a decrease in the level of T-lymphocytes. On the 3-5th day from the start of treatment, the itching decreased in patients, sleep and well-being improved. On the 8-10th day, the itching stopped, hyperemia decreased, infiltration began to decrease, papules flattened. In 26 patients, this condition was also observed at the end of the course, and in 46 patients, infiltration and desquamation were resolved – remission occurred. Only 5 patients showed no effect of the therapy. Consequently, in 93.5% of patients with atopic dermatitis, clinical recovery or improvement in the skin process was noted. Complications and side effects were not observed.

As a result of the analysis of the data obtained after treatment, it was found that the level of IgA, IgM, IgG did not change and remained significantly reduced in relation to the control, the CIC value also did not change. The therapy had no effect on B-lymphocytes, the relative number of which remained within the normal range. At the same time, a significant increase in the number of T-lymphocytes is noteworthy – from 37.51% ± 1.99% to 42.95% ± 3.1% (P> 0.05) and the normalization of the response of T-lymphocytes to nonspecific mitogen — from 66.68% ± 1.31% to 60.56% ± 2.64% at Р<0.05. The most significant changes were noted in the IgE level after treatment, it was found that as a result of treatment with vilozep, it decreased by half and reached 22.14 cu/l ± 6.28 cu/l compared with the initial data of 50.29 cu/l ± 7 .6 cu/l (P<0.05).

A high level of IgE in patients with atopic dermatitis before treatment is associated with the peculiarities of the mechanisms of its synthesis, as well as with a weakened suppressor function of T-lymphocytes, which limit this process. It is known that vilozen accelerates the differentiation of T-lymphocytes, contributing to an increase in the number of suppressor cells.

Thus, a deficiency of immunoglobulins of classes A, M, G, a decrease in the number of T-lymphocytes, a change in the response of lymphocytes to the action of a mitogen, an increase in the number of CIC and IgE levels suggest that patients (AD) have disorders in the functional state of cell-mediated immunity. The increase in the number of T-cells caused by vilozen, which correlates with a decrease in the level of IgE in the blood serum of patients (BP), indicates its effect on the differentiation of T-lymphocytes. Since, due to the insufficiency of T-cells, the body is not able to suppress the reactions leading to the formation of IgE, the use of vilozen in patients with atopic dermatitis seems justified.

event_note May 28, 2022

account_box Dr. Peter B Milburn

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