Flow cytometric analysis of lymphocyte subpopulations after thermal injury in human beings.

Several theories have been advanced in an effort to explain immunologic suppression after thermal injury, that is monocyte production of immunoregulatory prostaglandins, activation of suppressor cells, production of suppressive serum factors and alteration in helper cell function. In the current study, cytofluorometric analysis was performed on peripheral blood mononuclear cells isolated from 30 severely burned individuals using a FACS IV cell sorter. Fluorescein labeled monoclonal antibodies were used to phenotype total T cells (OKT3+), helper cells (OKT-4+), suppressor cells (OKT-8+), monocytes (antimono.2+) and B cells (anti-Ia+). After burn injury, the most striking phenotypic alterations observed were a marked decrease in the number and percentage of total OKT3+ T cells and OKT4+ helper cells. No significant increases were observed in the OKT8+ suppressor cell subpopulation. Monocytes exhibited a transitory increase during the first 48 hours postburn which returned to normal by postburn day 7. The percentage of Ia+ cells were either normal or decreased in number during the course of the injury. An OKT-4 to OKT-8 ratio of less than 1.00 at 24 to 48 hours postburn may represent a reliable predictive index for death by sepsis. These data suggest that the syndrome of burn induced immunologic suppression may be better described as a "burn induced immunodeficiency syndrome," that is characterized by decreased numbers or function of Interleukin-2 producing helper cells, or both.

Autologous and allogeneic mixed-lymphocyte responses following thermal injury in man: the immunomodulatory effects of interleukin 1, interleukin 2, and a prostaglandin inhibitor, WY-18251.

A group of 30 burn patients with 36-87% total body surface area (TBSA) burns was studied at 24-48 hr postburn. These included studies of (1) autologous and allogeneic mixed-lymphocyte reactions (MLR); (2) the immunoregulatory influence of mitomycin C-treated T cells, non-T cells, and unfractionated peripheral blood lymphocytes (PBL) on allogeneic MLR; and (3) correlation between the proportions of T-cell subsets defined with monoclonal antibodies (OKT4 and OKT8) and autologous MLR. Studies concerning adherent cell production of thromboxane, prostaglandin E2, and prostaglandin F2a and the immunomodulatory effects of Interleukin 1 (IL-1), Interleukin 2 (IL-2), and a prostaglandin inhibitor, WY-18251, on autologous MLR are presented. The autologous mixed-lymphocyte reaction was depressed in 60% of the burn patients tested. This depressed response correlated closely to the extent of third-degree injury (P less than 0.025) and to TBSA injury greater than 60% (P less than 0.025). A linear correlation was observed between the depression in autologous MLR and a decrease in both the percentage of OKT4+ T cells and the OKT4+/OKT8+ ratio. The response of T cells from burn patients in allogeneic MLR was normal. Age, sex, TBSA of the burn, and size of second-degree burn did not correlate with the abnormalities observed in MLR. Mitomycin C-treated mononuclear cells, purified T cells, or non-T cells from burned patients did not demonstrate any suppressive influence on MLR in normals. Monocyte number and arachidonic acid metabolism were investigated. In addition to increased numbers of monocytes following thermal injury, adherent cells produced increased quantities of thromboxane, prostaglandin E2, and prostaglandin F2a. The effects of Interleukin 1, Interleukin 2, and a prostaglandin inhibitor, WY-18251, were studied in autologous MLR (AMLR) of burned and normal patients. Interleukin 1 and WY-18251 did not induce any significant changes in proliferation in burned patients or normal controls. When compared to cultures without exogenous IL-2, an increase in AMLR was observed following the addition of IL-2 to burn patient cultures at Day 6 and Day 7 of culture. Although the addition of IL-2 did increase proliferation in AMLR of normal controls at Day 6 and Day 7, the enhancement observed for the burn patient cultures represented a restoration to the level of normal control cultures without IL-2. A dose-dependent increase in AMLR was observed in T cells isolated from normal and burned patients in the presence of purified Interleukin 2.(ABSTRACT TRUNCATED AT 400 WORDS)