Inflammatory, degenerative and vascular lesions in long-term dialysed patients

No other medical field but nephrology showed so important achievements as a result of concerted efforts of doctors, biologists and technicians. Considering that in renal insufficiency, regardless of its aetiology, the common path is represented by the transitory or definite damage of the "renal filter", many attempts have been made in order to reproduce the process of blood cleaning by the kidney.

The high prevalence of cardiovascular diseases in hemodialysed population suggested that the disease could begin before or during the stage of chronic renal insufficiency. We investigated the vascular lesions, especially the immunologic features of patients involved in hemodialysis programs. Our study reflects a general picture of the immunologic status of hemodialysed patients, helping to understand the special profile ofa hemodialysed patient.

Two groups have been selected and analyzed: one of 15 patients from the Hemodialysis Department in "Sfântul Ioan" Hospital, and another one composed of 30 patients with other diseases (the control group), from the Medical Department. The detection of specific antibodies against some HCV proteins corresponding to the most conserved regions of the viral genome has been done using the immune test LiaTEK HCV III. In the hemodialysed group, a blood sample has been drawn before and after the hemodialysis session, at 15-20 minutes, while in the other group the blood sample has been drawn together with the other tests. A flow cytometry examination was made at the Center of Immunology, in order to determine simultaneously several physical and chemical parameters. We analyzed the two groups of patients (HD/n=15; the reference group/n=30) regarding immunophenotyping, all types of lymphocytes and interleukin 2 (IL-2).

The results have classified the HD patients into three subgroups, depending on the mean of the results from flow cytometry exam, referred to normal values. The assessment of the patients with or without HD to each group was made on the basis of the similar behavior of the markers investigated. The most affected age group in patients with HD was 31-40 years, followed by the age group 41-50 years (26%). The majority patients of the control group were of the same age 31-40 years old (40%), while 33% of them were between 41 and 50 years old. One subgroup (A) of HD patients showed the improvement of the total number of T lymphocytes (CD3+/CD19-) after the session, while the total number of B lymphocytes was stable. The number ofT lymphocytes with receptors for interleukin 2 (CD25) improved after hemodialysis. The second group (B) presented from the beginning a low number of total T lymphocytes (CD3+/CD19-). We found that the value of B lymphocytes (CD19+/CD3-) decreased after hemodialysis. Activated T lymphocytes (CD25), with receptors for interleukin 2, achieved greater values (3.66%), which cannot be found in the other groups. The third group (C) showed normal values for total T lymphocytes (CD3+/CD19-) before HD, which did not modify significantly after the session. The patients had the same decreased values for B lymphocytes, which have continued to decrease after the HD (7.98%).

Post dialytic immunologic changes of the mononuclear cells represent the hallmark of the complexity of the immune response generally and especially too, in hemodialysed patients. We have noticed patients that presented an increase of the total number of T lymphocytes after the dialysis, but only T and NK lymphocytes and not B lymphocytes as well, suggesting the susceptibility to infections. The evaluation of the immune response using flow cytometry has confirmed the presence of high variations of the immune profile in hemodialysed patients, the decrease of T-cells activation but, it does not support the data regarding intrinsic functions of T and B cells. The high diversity of the immune response in hemodialysed patients is a consequence of the genetic individuality of each patient and also of the associated pathology or equipment used (viral infection, membrane type).