A Response to Article “Do Mesenchymal Stem Cells Influence Keloid Recurrence?” [Response to Letter]

Dear editor

In their recent perspective, Noviantari et al¹ review our recent publication titled “Do Mesenchymal Stem Cells Influence Keloid Recurrence?” and highlight that we failed to use The International Society for Cellular Therapy (ISCT) three prerequisites before designating cells as MSCs. While we are in agreement with the ISCT criteria for the characterization of MSCs (with flow cytometry, adhesion to the plastic surface and differentiation ability), this was a challenge for us in this study. As this was a longitudinal prospective study of 61 keloid and a control group of 32 patients, fulfilling all three ISCT criteria would require a lot of technical support and would also be very expensive beyond the budget limit of the study.

Noviantari et al¹ also mention that they did not find any histopathological analysis. The diagnosis of keloid was made through both clinical examination and confirmed by histology of the specimens. A qualified dermatopathologist analysed all the specimens and confirmed whether they were keloids or not. For normal skin, this was taken from patients undergoing elective surgical procedures with no skin pathologies.

The current challenge for clinicians and immunologists is to find a phenotypic classification for MSCs that is simple enough and yet specific and sensitive to be useful in a clinical setting. Studies using modern analytical approaches including single cell RNA sequencing support incorporating new findings to the ISCT criteria to accurately define stemness and MSCs.