Leg ulcers present a common and recurring problem in older people creating discomfort and distress for the patient and a great cost to the health care services. Cultured keratinocyte grafts have been used by many investigators to stimulate healing of chronic venous ulcers. It has been proposed that they may do this by producing cytokines which modulate the healing process. However, the types and levels of cytokines in the leg ulcer fluid before and during healing are not known. Wound fluid was collected from venous leg ulcers in 18 patients beneath occlusive Tegaderm dressing for 4 to 6 h. The leg ulcers were divided on clinical criteria into 'healing' and 'non-healing'. PDGF-AB, GM-CSF, IL-1 alpha, IL-1 beta, IL-6 and bFGF were measured by ELISA and the levels of IL-1 alpha, IL-1 beta and IL-6 were also measured using biological assays. The effect of leg ulcer wound fluid on fibroblast and keratinocyte proliferation was measured indirectly by 3H-thymidine incorporation and MTT assay. Total protein, albumin levels, fibronectin degrading activity and collagenase activity, both active and latent were measured. No statistically significant differences in the levels of cytokines or collagenase were identified between healing and non-healing leg ulcers in the sample of leg ulcers studied. However, this study does give valuable information concerning the levels of cytokines and collagenase in chronic leg ulcer wound fluid.

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Malassezia spp., the causative agents of pityriasis versicolor, are members of the normal human cutaneous microflora. Utilizing a combination of both enzyme‐linked immunosorbent assay (ELISA) and bioassay, we have investigated the ability of both formalin‐preserved and viable Malassezia (serovars A, B and C) to modulate pro‐inflammatory cytokine (IL‐6, IL‐1β and TNF‐α) release by human peripheral blood mononuclear cells (PBMNC) in vitro, over a 48‐h co‐incubation period. The results demonstrated that formalin‐preserved Malassezia (serovars A, B and C) at midexponential phase were generally able to induce a pro‐inflammatory cytokine response at a yeast cell to PBMNC ratio of 1:1. In addition, the results consistently demonstrated that at a yeast cell to PBMNC ratio of 20:1, formalin‐preserved Malassezia, irrespective of serovar, growth phase or PBMNC donor, were capable of significantly (P<0·05) decreasing the release of both immunochemical IL‐6 and IL‐1β plus bioactive IL‐1β and TNF‐α below that of unstimulated culture medium control values. This was apparent following 24‐ and 48‐h co‐incubation times, where maximal cytokine production was detected after 24 h. Similar results were obtained for the effect of viable Malassezia on pro‐inflammatory cytokine release by PBMNC. Our results suggest that a possible inhibitory component, present perhaps within the cell wall of Malassezia, was responsible for this depressive effect on pro‐inflammatory cytokine production.

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