A comparative study to assess the efficacy and composition of various cell populations of extracted hair follicle outer root sheath cell suspensions (EHF ORS CS) prepared using a single enzyme (trypsin) and multiple enzymes (trypsin and collagenase) for transplantation in vitiligo

Vitiligo is an acquired autoimmune depigmenting disease with multifactorial etiology. Many modalities have been used to treat it, both surgical and non-surgical, but there is still a need for a treatment that is promptly and uniformly effective, without causing donor site scarring. Replenishing melanocytes selectively within vitiliginous macules by autologous non-cultured melanocyte-keratinocyte cell suspension transplantation is a promising treatment.

NCEHF ORS CS (Non-cultured extracted hair follicle outer root sheath cell suspension) is prepared from  outer root sheath of hair follicles, extracted by follicular unit extraction (FUE) method. The outer root sheath of hair follicles is a richer source of melanocytes and their precursor stem cells than the epidermis. (The ratio of melanocytes to keratinocytes in the epidermis is 1:36, while that in the hair follicle is 1:1 to 1:6). The suspensions from it would contain higher number of melanocytes, and various populations of stem cells (melanocyte stem cells, mesenchymal stem cells and keratinocyte stem cells), the composition may vary. One of the attempts will be to correlate the treatment response with these parameters.

Comparison will be in terms of- clinical outcome, rapidity of repigmentation , cell yield, types of cells as evaluated by immunohistochemistry, flowcytometry.  The preliminary work done in our lab suggests that the cell count in suspension obtained from split thickness epidermal graft is 2 to 4 times higher than EHF ORS CS. The extracted hair follicles have a dermal sheath all around which may be hampering the contact of trypsin with outer root sheath and thus affecting cell yield. Therefore we feel that addition of collagenase type-1 will facilitate lysis of peri follicular dermal sheath and contact of trypsin with outer root sheath.

Outer root sheath of hair is a good potential source of mesenchymal stem cells, which potentially will expand indications of uses of such a cell suspension in other diseases where mesenchymal stem cells are potentially therapeutic, examples including wounds and inherited blistering skin diseases.