Correspondence
SirThe conclusion of Ausobsky et al. (Br. J . Surg. 1982; 6 9 346-8), that skin testing is not predictive of postoperative problems, raises four points that deserve comment. First, the authors' patient numbers are far too small to conclude that skin testing is of no value in studying a patient population. Their incidence of major sepsis is higher among anergic than reactive patients, and though statistical significance is not reached, this certainly does not rule out an association. The low incidence may also reflect the high percentage of clean cases defined in their text.Secondly, the authors state that 'skin hypersensitivity tests are, however, only indicators of cell-mediated immunity, and d o not reflect the defensive powers of macrophages or polymorphonuclear leucocytes'. In fact, although skin testing has traditionally been used as a clinical test of so-called cell-mediated immunity, the great majority of cells infiltrating a skin test site are immunologically non-specific cells (mainly monocytes and lymphocytes, and including neutrophils) recruited from the blood by specifically sensitized T lymphocytes (I).Therefore, the skin test requires a number of specific and non-specific functions to be carried out. Several cell types and humoral factors are involved, making the skin test far more than just an assessment of 'cellmediated immunity' or T-cell function. Furthermore, patients with cutaneous anergy have been found to have abnormal neutrophil function and serum inhibitors of neutrophil chemotaxis (2.3).As a third comment we must object to the authors' omission of relevant information about their study. In a follow-up article (4), which deals with the same 166 patients as described in their above mentioned first paper, Ausobsky et al. indicate that roughly half their patients received perioperatively the immunomodulating agent levamisole. This fact is not included in the first report. Finally, there is a major discrepancy in the descriptions of the patient population given in the two papers. Their earlier report states in Table IV that 66 of the 166 patients had a malignant tumour; the more recent paper (4) claims in Table I that 89 of the 166 patients had a malignancy.We agree that the question of which comes first, sepsis or anergy, is valid. To determine if sepsis induces anergy in patients is difficult; however, in an animal model (5), previously reactive rats became anergic after sepsis was induced. Therefore, it does appear that sepsis among many other factors may lead to anergy and further defects in host defences. J. M. BOHNEN 1. Marchal G . , Seman M.. Milon G. et al.: Local adoptive transfer of skin delayed-type hypersensitivity initiated by a single T lymphocyte. J. Immunol. 1982; 129: 954-8. Christou N. V. and Meakins J. L.: Neutrophil function in surgical patients: two inhibitors of granulocyte chemotaxis associated with sepsis. J. Surg. Res. 1979; 26: 355-64. tion of serum inhibitors of neutrophil chemotaxis associated with anergy. J. Immunol. 1974; 113 189-200. Ausobsky J. R....