Mohs micrographic surgery revisited: A multidisciplinary, collaborative approach for the treatment of aggressive and recurrent basal cell carcinoma on the head and neck.

Mohs micrographic surgery is the preferred surgical option for high-risk basal cell carcinomas. In our institution, the method is exclusively used for the treatment of aggressive and recurrent facial tumours selected via multidisciplinary team meetings and consistently managed using a multidisciplinary approach. The aim of this retrospective patient-record study was to examine the outcomes for basal cell carcinomas managed with Mohs micrographic surgery and to present our experience from multidisciplinary team meetings and interdisciplinary collaborations. All patients treated between September 2009 and March 2019 at Karolinska University hospital were included. In a total of 143 facial basal cell carcinomas in 138 patients, 86 primary and 57 recurrent, the recurrence rate was 4.9% after a median follow-up of 24 months. In regions, where highly specialised Mohs surgeons performing all the steps of the procedure are limited, interdisciplinary collaboration can be an effective strategy for appropriate patient selection and for performing all steps of Mohs surgery with dermatosurgeons eradicating the tumour, pathologists evaluating the histopathology, followed by reconstructive surgery by plastic surgeons. The approach we present here provides a robust and functioning Mohs surgical service during the build-up of the organisation, while providing the opportunity to train new surgeons. Once the clinic has been set up, the multidisciplinary approach should always be considered and applied when dealing with complex cases.

Injury downregulates the expression of the human cathelicidin protein hCAP18/LL-37 in atopic dermatitis.

Reduced production of antimicrobial peptides was proposed to contribute to susceptibility for skin infections in atopic dermatitis (AD). Focusing on the human cathelicidin protein, hCAP18, the aim of the present study was to explore whether reduced hCAP18 expression is a constitutive trait in AD and if established inducers affect the expression of hCAP18 in the skin of AD. First, we compared levels of hCAP18 mRNA between lesional skin in AD and psoriasis and verified significantly lower expression of hCAP18 mRNA in AD. In non-lesional skin, however, there was no difference between AD, psoriasis and healthy, indicating that there is no constitutive defect in the production of hCAP18 in AD patients. In healthy skin, hCAP18 was reported to be rapidly induced following wounding and here we verified this pattern in healthy controls and in psoriasis. In AD lesions, however, the expression of hCAP18 mRNA was markedly suppressed following wounding. Obviously, the inflammation in AD lesions neutralizes the expected induction of hCAP18 and even induces suppression. Notably, the mechanism to upregulate hCAP18 following vitamin D treatment was functional in lesional as well as in non-lesional AD indicating that the CAMP gene is normally regulated in this respect. In addition, cultured primary keratinocytes from non-lesional skin of psoriasis, AD and healthy skin, upregulated hCAP18mRNA following treatment with vitamin D. Itching is a hallmark of AD and scratching inevitably injures the skin. Failure to upregulate hCAP18 in eczema following injury is likely to affect antimicrobial protection and tissue repair in AD.

Antimicrobial protein hCAP18/LL-37 is highly expressed in breast cancer and is a putative growth factor for epithelial cells.

Human cathelicidin antimicrobial protein hCAP18/LL-37 is an effector molecule of the nonspecific innate immune system. hCAP18/LL-37 is present in leukocytes and is expressed in skin and other epithelia, where it is upregulated in association with inflammation and injury. In addition, antimicrobial proteins including cathelicidins have been proposed to play a role in the nonspecific defense against tumors. To assess its potential role in tumor host defense, we investigated the expression of hCAP18/LL-37 in a series of breast carcinomas. Unexpectedly, we found that hCAP18/LL-37 was strongly expressed in the tumor cells and not in the adjacent stroma. To test the hypothesis that hCAP18/LL-37 may provide a growth advantage for the tumor cells, we treated human epithelial cell lines with synthetic biologically active LL-37 peptide and found a significant increase in cell proliferation. In addition, transgenic expression of hCAP18 in 2 different human epithelial cell lines resulted in increased proliferation of both cell types. These findings do not support the hypothesis that LL-37 has an antitumor effect, but rather suggest that hCAP18/LL-37 may promote tumor cell growth in breast cancer.

The cathelicidin anti-microbial peptide LL-37 is involved in re-epithelialization of human skin wounds and is lacking in chronic ulcer epithelium.

The human cathelicidin anti-microbial protein, hCAP18 is a component of the innate immune system and has broad anti-microbial activity conferred by its C-terminal fragment LL-37. hCAP18 is constitutively produced in leukocytes and is induced in barrier organs upon inflammation and infection. We demonstrate here a novel role for this peptide in re-epithelialization of skin wounds. We show that high levels of hCAP18 are produced in skin in vivo upon wounding. The highest hCAP18 levels are attained at 48 h post-injury, declining to pre-injury levels upon wound closure. hCAP18 is detected in the inflammatory infiltrate and in the epithelium migrating over the wound bed. In chronic ulcers, however, hCAP18 levels are low and immunoreactivity for hCAP18/LL-37 is absent in ulcer edge epithelium. Using a noninflammatory ex vivo wound healing model, composed of organ-cultured human skin, we show that hCAP18 is strongly expressed in healing skin epithelium, and that treatment with antibodies raised and affinity purified against LL-37, inhibits re-epithelialization in a concentration-dependent manner. Immunoreactivity for the proliferation marker Ki67 is absent in the epithelium of such inhibited wounds, suggesting that LL-37 may play a part in epithelial cell proliferation. Thus, we suggest that, in addition to being an anti-microbial peptide, LL-37 also plays a part in wound closure and that its reduction in chronic wounds impairs re-epithelialization and may contribute to their failure to heal.