What Can Microdialysis Tell Us About the Temporal and Spatial Generation of Cytokines in Allergen-Induced Responses in Human Skin In Vivo?

Abstract

This study examined the suitability of microdialysis to assess the time course of cytokine generation from discrete sites within the skin following intradermal injection of allergen. Cytokines were recovered using two microdialysis probes, one close to the point of allergen injection and the other 1 cm away but within the area of the late-phase induration. Skin biopsies taken at both sites were stained immunocytochemically to investigate possible relationships between cytokine generation, expression of adhesion molecules, and recruitment of neutrophils and eosinophils during the late-phase allergic response. The cytokine response to probe insertion was assessed using a single probe in the opposite arm (control). At baseline, microdialysate contained low levels of IL-1alpha, IL-5, IL-8, IL-12, GM-CSF, and TNFalpha (n=27-33). At control sites, this was followed by increases in IL-6 and IL-8 at 3 and 6 hours. Allergen increased TNFalpha levels in 3/11 individuals within 30 minutes at the injection site. Levels of IL-6 and IL-8 rose rapidly and were significantly greater (P<0.05) than that of controls at 3 and 6 hours at both injection and distant sites. Adhesion molecule expression and leukocyte infiltration were elevated only at the allergen injection site, suggesting a complex relationship between cytokine generation and cellular events in allergic inflammation. In conclusion, microdialysis can be used to distinguish temporal and spatial changes in protein profiles in the skin. Furthermore, when used in conjunction with skin biopsies, it provides novel information about the mechanisms of dermal inflammation.

Are Cutaneous Microdialysis Cytokine Findings Supported by End Point Biopsy Immunohistochemistry Findings?

“…The issues of tissue reactivity, levels of trauma and recovery (equilibration) times are central to any discussion of CMD. This is especially so in the interpretation of findings on cytokines and other biologically active molecules such as chemokines and growth factors (9,10,(17)(18)(19), which patently have longer "equilibration" times than axon reflex-mediated microvascular events (11)(12)(13). Other central issues concern whether membranes retain their laboratory bench determined function in relation to passage of target molecules in vivo in the short-(e.g.…”

“…In the translation of findings to the human (clinical) in vivo situation, the main methods of obtaining data have been peripheral blood, which summates effects at a whole organism level, and skin biopsy, which gives tissue-specific (skin) data on the presence of or gene induction for the production of a protein at the specific time point the biopsy was taken. Cutaneous microdialysis (CMD) enables continuous in vivo sampling of the interstitial fluid in the intact skin and is thus an attractive, newer and arguably less tissue destructive alternative for the measurement of cytokines actually present in the dermal extracellular environment over a period commensurate with the expected pathogenesis of the reaction under study (6)(7)(8)(9)(10)(11). The present study is on normal skin and combines CMD with end point biopsy for immunohistochemistry of the actual microdialysis area to compare the findings of the two methodologies at a specific time point, 24 h.…”

Influence of surface modification and static pressure on microdialysis protein extraction efficiency

“…Therefore, 3,000 kDa MWCO plasmapheresis type membranes are often used (Winter et al 2002;Clough et al 2007). …”

“…MD is well established as a clinical sampling tool for monitoring small hydrophilic molecules such as lactate, puruvate and glucose in neurointensive care settings (Hillered et al 2005;Helmy et al 2007). There is a growing interest in monitoring larger and more complicated molecules such as neuropeptides (Rosdahl et al 2000;Dahlin et al 2004;Schutte et al 2004), cytokines (Ao and Stenken 2006) and proteins (Kjellstrom et al 1999;Clough et al 2007;Dahlin et al 2010). Monitoring larger molecules requires ultra-filtration or microfiltration membranes with molecular weight cut off (MWCO) of 100 kDa or above.…”

Multiplexed cytokine detection of interstitial fluid collected from polymeric hollow tube implants—A feasibility study

“…Microdialysis sampling has been used to collect cytokines from the skin under various conditions [22,23]. While these studies were not intended to test a type of material chemistry during implantation, they do illustrate that cytokines can be collected from an implantation site surrounding a polymeric membrane.…”