Dialyzed leukocyte extract (DLE) (Immodin SEVAC, Czech Republic) was shown to enhance the recovery of the pools of hemopoietic stem cells (CFUs) and of granulocyte-macrophage hemopoietic progenitor cells (GM-CFC) in the bone marrow in vivo, as well as to increase the numbers of leukocytes and thrombocytes in the peripheral blood of mice exposed to a sublethal dose of gamma-rays, with an ensuing increase in the numbers of mice surviving the lethal radiation dose. In experiments performed in vitro, DLE or sera of mice administered with DLE were added to cultures of intact mouse bone marrow cells containing suboptimal concentrations of hemopoietic stimulatory cytokines, namely recombinant mouse interleukin-3 (rmIL-3) or recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF); under these experimental conditions, both DLE and sera of mice administered DLE were found to increase the counts of GM-CFC colonies in the cultures. It can be hypothesized on the basis of the findings obtained in vitro that the described co-stimulating activity (CoSA) of DLE may play a role also under in vivo conditions; the enhancement of the recovery of hemopoiesis suppressed by ionizing radiation may be due to a co-operation of the stimulatory effects of DLE with the action of cytokines endogenously produced in irradiated tissues.

At present an increase of some autoaggressive diseases can be observed. The commonly used treatment consists of the administration of some immunosuppressive drug of some hormonal preparations. This type of therapy is accompanied by some undesired side effects, as these drugs influence also some other cell systems besides the immunologically active cells. These drugs are also known to lower the resistance to some intercurrent infections. Due to these undesired side effects some naturally occurring factors are introduced into the therapy. These are e.g., TGF-beta, or some interleukins (IL-10 etc.). In our department and immunosuppressively acting substance was isolated from DHL which had the ability to inhibit the AA (adjuvant arthritis) in rats. In humans this SF (suppressive factor) stimulates the CD 8+ cells which are known to have suppressoric activity. This SF was successfully applied in some autoaggressive diseases, e.g., atopic eczema, multiple sclerosis, some polyradiculoenuritis, amyotropic lateral sclerosis etc. In this paper the results in the ALS patients are given. Amongst other possibilities of the therapy the application of antilymphocyte sera, monoclonal antibodies to some CD markers of lymphocytes and some methods of hyposensitizations of tolerance induction are mentioned. Further, an original method using antigen bound to isosoluble carrier is described. This administration of encephalitogen bound onto Sforon (polyacrylate spheres) sis not only inhibit the EAE manifestations but also enable the survival of guinea-pigs which had already manifested the clinical signs of EAE.

The influence of dialyzable extract from human leukocytes (DLE) on the in vitro growth of the granulocyte-macrophage colony-forming cell (GM-CFC) colonies from progenitors of mouse bone marrow cells was studied. DLE alone did not induce the colony growth but it modulated the number of colonies if administered together with a colony-stimulating factor (CSF). The costimulatory effect prevailed in a broad range of DLE dilution and the index of increase was enhanced with the lowering of the CSF concentration. The costimulatory augmentation of clonal proliferation of GM-CFC with DLE was further strengthened by addition of indomethacin, thus indicating an intervening role of prostaglandins in the modulatory influence of DLE.

Forty amyotrophic lateral sclerosis (ALS) patients were treated with suppressor factor. The therapy led to the normalization of the immunoregulatory index in approximately two thirds of the patients. The responder patients had a better clinical response, i.e. the degenerative process slowed down or it was even arrested. This favourable effect was accompanied with a significant increase in the patients' life span. When the therapy had no effect on the CD8 cells, it was discontinued. Stopping the therapy led to disease progression and death; thus, in some patients, therapy was carried out despite its failure to increase the CD8 cell numbers. Substantial clinical improvement was noticed in these patients. The mean survival of patients with ALS was 2-3 years, whereas ALS patients treated with the suppressor factor survived on the average more than 5 years.

A group of 222 patients suffering from cellular immunodeficiency (CID), frequently combined with chronic fatigue syndrome (CFS) and/or chronic viral infections by Epstein-Barr virus (EBV) and/or cytomegalovirus (CMV), were immunologically investigated and treated with transfer factor (TF). The age range was 17-77 years. In order to elucidate the influence of aging on the course of the disease and on treatment, 3 subgroups were formed: 17-43 years, 44-53 years, and 54-77 years. Six injections of Immodin (commercial preparation of TF by SEVAC, Prague) were given in the course of 8 weeks. When active viral infection was present, IgG injections and vitamins were added. Immunological investigation was performed before the start of therapy, and subsequently according to need, but not later than after 3 months. The percentages of failures to improve clinical status of patients were in the individual subgroups, respectively: 10.6%, 11.5% and 28.9%. The influence of increasing age on the percentage of failures to normalize low numbers of T cells was very evident: 10.6%, 21.2% and 59.6%. In individuals uneffected by therapy, persistent absolute lymphocyte numbers below 1,200 cells were found in 23.1%, 54.5% and 89.3% in the oldest group. Statistical analysis by Pearson's Chi-square test, and the test for linear trend proved that the differences among the individual age groups were significant. Neither sex, nor other factors seemed to influence the results. The results of this pilot study show that age substantially influences the failure rate of CID treatment using TF. In older people, it is easier to improve the clinical condition than CID: this may be related to the diminished number of lymphocytes, however, a placebo effect cannot be totally excluded.

Dialysable leucocyte extract (DLE) prepared from buffy coats of human blood, potentiates the effect of Colony-stimulating factor (CSF) on the growth of granulocyte-macrophage colony forming cell (GM-CFC) colonies in vitro. This relative increase of the number of colonies is apparent when diluted CSF (present in lung conditioning medium) as a control, and DLE, in a wide range of concentrations are added to the culture of mouse bone marrow cells. Fractionation of DLE on Amicon membranes revealed that the activity resides in molecules of 0-5kD. Molecules 5-10kD have no potentiating effect. DLE and its fractions (0-5kD, 0-1kD), except fractions 0-500 D and 5-10kD, when added undiluted i.e. at the initial concentration, exerted a suppressive effect: colonies are not formed despite the presence of CSF. In a pilot experiment, it was shown that DLE is able to stimulate colony-forming activity of earlier progenitors of erythroid cells (BFUe), under the influence of erythropoietin.

Using a blood cell separator, lymphocytes were collected from otherwise healthy convalescents suffering from herpetic infections. A specific anti-herpes dialysate (AH-DLE) was prepared from the lymphocytes, using standard procedures. Patients with recurrent herpetic infections were treated with a single dose of the dialysate, at the initial signs of herpetic infection (group A), with two doses (group B) or with three doses (group C). A total number of 37 patients (29 women, 8 men, age range 15-73 years) were treated. No improvement was observed in 7 patients (18.9%), whilst 7 patients did not manifest any exacerbation of their herpetic infection in the course of the one-year follow-up. The remaining 62.2% of the patients showed a marked improvement: decrease of the frequency and/or duration or relapses. Before AH-DLE administration, the mean number of herpes relapses in this group of patients was 12 p.a.. After therapy, the number of relapses decreased to 3.5 p.a.. No statistically significant difference was observed between groups A and B. The least favourable results were registered in group C. However, this group included 6 female patients extremely resistant to the previously therapeutic attempts, including inosiplex, non-specific DLE or acyclovir. Thus, even in this group, the therapy was successful in 50% of the patients.

Adjuvant-induced arthritis in rats is a chronic inflammatory disease, widely used as an animal model for rheumatoid arthritis. In our study the effect of various fractions of dialyzable leukocyte extract (DLE): DLE I-molecular weight below 10 kDa (commercial preparation), DLE II-molecular weight below 5 kDa (suppressor fraction), DLE III-molecular weight 5-10 kDa on rat adjuvant-induced arthritis was studied. The adjuvant arthritic (AA) rats were treated with DLE fractions i.p. in solutions containing an active substance isolated from 12.5 x 10(6) and 6.25 x 10(6) leukocytes from day 1 (adjuvant injected) through day 18, every second day (total 9 times). Various markers of inflammation, immune function and joint destruction were evaluated: hindpaw volume, serum hyaluronic acid, serum albumin and biopterin in urine. All these markers showed a significant improvement after using fraction DLE II in comparison with AA controls. Fractions DLE I and DLE III influenced only some markers of inflammation and immune function. Our results demonstrated a therapeutical effect of fraction DLE II on rat adjuvant-induced arthritis.

A low-molecular leukocyte dialysate, suppressor transfer factor (STF), exerting a stimulating effect on CD8 subpopulations in man, was administered to 17 patients with amyotrophic lateral sclerosis (ALS). Following three s.c. injections of STF, activation of CD8 subpopulations was noted in 11 patients while a decrease in CD4 in seven. Progression of the disease was found to slow in nine outpatients administered STF injections at an interval of 3-4 weeks. No therapeutic effect was seen in four patients in whom STF injection failed to show stimulating activity on lymphocyte subpopulations. Remission of the stimulating effect of STF occurs within four weeks. No side effects were seen in any of the patients treated. The effect of STF on immune reactivity and on the clinical course of ALS supports the hypothesis of autoimmune character of the disease.

Various theories have been put forward to explain the regenerative capacity of liver tissue induce by partial hepatectomy (PH). One of them presumes the existence of humoral factors stimulating proliferation of the liver tissue. We evaluated the course of liver regeneration after 65-70% PH as influenced by dialysates (DIA) of the organs of a rat killed 17 h after PH. In addition to kidney DIA, we were particularly interested in the effect of liver and spleen DIA. The experiments were carried out on rats weighting 310-370 g. Kidney, liver or spleen dialysate was administered subcutaneously and the rats were killed 12 or 24 h later by exsanguination from the abdominal aorta. In further rats, PH was performed 24 h after administering DIA and the rat were killed 18, 24, 30, 48 and 72 h after the operation. The initiation of liver regeneration was stimulated by all the given DIA, but especially by liver DIA. The faster onset of liver regeneration 18 h after PH in rats given spleen DIA is interesting. DIA did not greatly affect the hepatocytes of intact liver, but accelerated the initiation of liver regeneration after PH by synchronizing the cell cycle of proliferating hepatocytes. DIA obtained 17 h after PH contained substances which primarily stimulated liver DNA synthesis. From the changes in inhibition of the migration of spleen macrophages in the medium containing liver antigens, and from the circulating immunocomplex values, we conclude that DIA activation of the immune system, a well as the hepatic stimulator substance contained in the DIA, participates in acceleration of the liver regeneration process.

Normal rabbit sera were found to be highly cytotoxic for chicken thymus cells. When the sera were fractionated on Sephadex G-200, the natural cytotoixc activity resided exclusively in the first peak. It was found to be complement-dependent and heat stable at 56 degrees. On the other hand, in the serum of immunized animals the specific cytotoxic activity appeared in the second peak.

Hypothesis postulating that various manifestations of delayed (cellular) hypersensitivity are due to biologically active mediators released by sensitized lymphocytes under the influence of specific antigen was formulated about 10 years ago (11, 12). It was substantiated for in vitro reactions by Bloom, David, ourselves and others (7, 18). Exact evaluation of present knowledge is in no way easy; a number of different mediators was described but they mostly cannot be separated biochemically and are induced also by nonspecific stimulation of lymphocytes. Their actual role for in vivo reactions of delayed hypersensitivity remains to be determined.

Peritoneal exudate lymphocytes (PEL), purified on glass beads and lymph node (LN) cells from guinea-pigs immunized with tubercle bacilli were cultured for 24 hours, in serum-free medium, without and with various concentrations of Tuberculin PPD. Supernatants obtained from cultures with 10 μg PPD/107 lymphocytes provoked an intense inflammatory reaction, when injected into the skin of normal guinea-pigs. PEL were more active than LN cells from the same animals. The reaction was characterized by erythema and induration, with a peak between 3 and 6 hours and histologically a mixed polymorphonuclear—mononuclear infiltrate in the dermis was seen. When fractionated on Sephadex G-200, skin activity of both PEL and LN supernatants was concentrated in a peak corresponding to the molecular weight of serum albumin, while in LN material some activity was also present in a small molecular weight peak. The active material could be separated from albumin by chromatography on DEAE-cellulose. Immunoelectrophoretic analysis of skin reactive peaks detected a slow α-globulin in both PEL and LN supernatants. PPD in the form of a complex with a protein precipitated by anti-γG antiserum, was detected in the skin-active Sephadex peak III of LN supernatants, by radioimmunoelectrophoresis. Skin activity was precipitated with ammonium sulphate at 66 per cent saturation and was destroyed by pepsin treatment. Formation of the skin-active material was depressed by Puromycin and Actinomycin-D and the development of skin inflammation was suppressed by pretreatment of the recipient with anti-lymph node extract serum. Evidence for antigen induced specific synthesis and release of an α-globulin in PEL and LN cultures was found but its relation to the skin active material is unknown.