H F deRiesthal | PubMed Health

PubMed1988

The decrease in peripheral blood CD4+ T cells following thermal injury in humans can be accounted for by a concomitant decrease in suppressor-inducer CD4+ T cells as assessed using anti-CD45R.

Using single- and two-color fluorescence flow cytometry, 10 thermally injured human subjects were assessed over time for both percentages and absolute numbers of lymphocytes comprising peripheral blood lymphocyte subpopulations. The CD3+ lymphocyte percentage decreased significantly in the early postburn period, and this decrease could be accounted for entirely by a concomitant decrease in the CD4+ lymphocyte percentage. Further, the decline in CD4+ percentage was due to a specific decrease in the suppressor-inducer subset of CD4 as defined using anti-CD45R. No change in the helper-effector subset of CD4 was noted. The percentage of CD8+ lymphocytes did not change significantly at any time postburn nor did subsets of CD8 as defined using anti-CD11. Numerical changes in lymphocyte subsets were dominated by a general lymphopenia occurring on Day 4 following injury. However, suppressor-inducer (CD4+/CD45R+) T cells also decreased significantly on postburn Day 1. These results further elucidate phenotypic changes in immunoregulatory subsets following major injury and suggest a possible basis for depressed autologous mixed lymphocyte responsiveness of burn patient T cells, one of the functional immunologic defects associated with severe injury.

Adult↗

PubMed1988

Granulocyte contamination of Ficoll-Hypaque preparations of mononuclear cells following thermal injury may lead to substantial overestimation of lymphocyte recovery.

During ongoing flow cytometric studies of burned patient blood leukocytes, it was noted frequently that large numbers of granulocytes were present along with the mononuclear cells at the plasma/Ficoll-Hypaque (F-H) interface following centrifugation over F-H. Since differential WBC counts are not routinely performed on F-H interface cells, it is possible that many previous immunologic studies of burned patients have greatly overestimated numbers of lymphocytes recovered. The present study sought to quantify the extent to which granulocyte contamination of F-H separated cells occurs following burn injury. Blood from 15 thermally injured patients (7-55% total body surface area burn) was studied serially at 24 hr, 48 hr, and weekly thereafter through 6 weeks postburn (PB). Controls were age-matched normals (No. of control bloods = 59). Three-part differential cell counts (lymphocytes, monocytes, and granulocytes) were performed on both F-H interface cells and RBC-lysed whole blood. Counts were performed by light scatter analysis on a flow cytometer. Except at 48 hr, at every time studied through 4 weeks PB, there was significant contamination of F-H interface cells with granulocytes. At 24 hr PB, 41 +/- 9% of the interface cells were granulocytes while at 4 weeks, PB 24 +/- 8% of the interface cells were granulocytes. The data did not support the interpretation that this increase in F-H interface granulocytes was simply reflective of the granulocytosis commonly observed after burn. Thus artificial generation of granulocytosis by addition of extra normal leukocytes to normal blood resulted in complete separation of granulocytes from mononuclear cells following centrifugation over F-H.(ABSTRACT TRUNCATED AT 250 WORDS)

Burns↗