Complement activation in dialysis: effects on cytokines, lymphocyte activation and beta 2 microglobulin.

Anaphylatoxins generated by complement activation by filter membranes are present in plasma during hemodialysis (HD). In the presence of endotoxins which may contaminate the dialysate, they can trigger monocytes to produce interleukin-1 (IL-1) and tumor necrosis factor (TNF), with detrimental effects for the patients. We have investigated whether or not the use of complement activating (cuprophan) and non- (or less-) activating membranes (polysulfone, polymethylmethacrylate or polyacrylonitrile) per se influences cytokine levels in HD patients. Our results indicate that if a sterile bicarbonate solution is used as dialysate, there are no significant increases in IL-1, TNF, interleukin-2 (IL-2) and soluble IL-2 receptors (sIL-2r) throughout HD, even with cuprophan membranes. Moreover even a prolonged use of this membrane (three months) did not change pre-dialysis levels of cytokines and receptors. Use of complement activating membranes also does not influence beta 2 microglobulin levels.

Effect of UVB plus tar therapy on serum levels of interleukin-2 receptors in patients with psoriasis.

Baseline serum levels of interleukin-2 receptor (IL2R) were measured in 65 patients with active psoriasis. IL2R levels in psoriatic patients were significantly higher than in healthy controls (582.4 +/- 289.23 u/ml vs. 369.64 +/- 111.10 u/ml; P less than 0.05), but did not differ statistically from values found in an atopic dermatitis control group (619.88 +/- 254.27 u/ml). Sex, age and severity of the disease do not affect levels of IL2R. The same IL2R levels were measured in 26 psoriatic patients receiving UVB plus tar therapy. This therapy, continued until clinical remission, lowered IL2R levels to values comparable to controls. This decrease may be due to an immunosuppressive effect of therapy.

T lymphocyte subpopulations in myelodysplastic syndromes.

T cell subpopulations, defined by monoclonal antibodies (OKT3, OKT4 and OKT8), were assessed on 13 patients with myelodysplasia (MDS). The percentage and numbers of OKT3- and OKT4-positive lymphocytes were significantly lower (p less than 0.025) than in normal controls, whereas those of OKT8 were not. In the group of patients with refractory anemia with excess of blasts (RAEB) and in those with chronic myelomonocytic leukemia, the percentage and absolute numbers of OKT8 lymphocytes were significantly lower (p less than 0.025) than in patients with refractory anemia or with primary acquired sideroblastic anemia, while those of OKT3 and OKT4 did not differ significantly. Quantitative impairment of T cell subpopulations may be part of the myelodysplastic situation as a result of the dyslymphopoiesis, according to the hypothesis that MDS originate from pluripotent stem cells. The decrease of OKT8 in RAEB and chronic myelomonocytic leukemia could be related to the previously shown insufficient erythropoietic activity in these patients.

A comparative study on peripheral blood lymphocyte subpopulations in different kinds of warts.

Peripheral blood T-cell subpopulations were evaluated in 36 patients with clinically different types of warts, subdivided in 4 groups (common, genital, flat and plantar warts). A significant decrease was found in OKT3 and OKT4 subsets total count and in OKT4/OKT8 ratio in patients with common and genital warts as compared with controls. Only in common and genital warts did we also observe a significant decrease of percentage of OKT4 subset. No significant difference of considered parameters was observed in flat and plantar warts as compared to controls, apart from a significant increase in number of OKT8 subset in flat warts. We then discuss this different status of C.M.I. in patients with different clinical warts, stressing the importance of various types of HPV.