Immunosuppressants and Skin Cancer in Transplant Patients: Focus on Rapamycin

Aggressive Cutaneous Squamous Cell Carcinomas Following Treatment for Graft-versus-Host Disease: A Case Report and Review of Risk Factors

A 19-year-old female with a history of pre-B cell acute lymphocytic leukemia (ALL) presented with two aggressive cutaneous squamous cell carcinomas (C-SCC) in the right hand. The patient was diagnosed with pre-B cell ALL at four years of age. She underwent chemotherapy with initial remission. However, recurrence of the pre-B cell ALL required an unrelated allogeneic cord hematopoietic stem cell transplant (alloHSCT). Post-transplant, the patient developed Graft-Versus-Host Disease (GVHD), which was treated with immunosuppressant therapy for six years until resolution. Fourteen years following the transplant, the patient developed a morbilliform drug eruption secondary to clindamycin. She consequently received prednisone treatment. During the treatment period, the patient developed a new ulcerated and tender nodule on the dorsal aspect of her right hand. Further histopathological biopsy confirmed the diagnosis of C-SCC, which required excision. Ten months following the excision, the patient developed an additional C-SCC nodule on the same right hand, separated by 2.6 cm from the prior C-SCC. She was referred for a ray resection procedure. This case illustrates a patient with multiple risk factors that may have contributed to the continued development of C-SCC. Such risk factors include: a prolonged course of immunosuppressant medications and voriconazole treatment. Additional research is needed to investigate the etiologies and risks of C-SCC development in patients who require a transplant and long-duration immunosuppressive therapy.

De Novo Carcinoma after Solid Organ Transplantation to Give Insight into Carcinogenesis in General-A Systematic Review and Meta-Analysis

Simple Summary

Patients receiving a solid organ transplantation, such as a kidney, liver, or lung transplantation, inevitably have to take drugs to suppress the immune system in order to prevent rejection of the transplanted organ. However, these drugs are known to cause malignancies in the long term. This study focuses specifically on newly developed carcinomas in patients who use those drugs after a solid organ transplantation. This systematic review and meta-analysis of published data show a 20-fold risk to develop a carcinoma after solid organ transplantation compared to the general population, with specifically increased risks in patients who receive cyclosporine or azathioprine. By comparing the different pathways involved in immunosuppression and the occurrence of carcinoma development, new insights can be discovered for future research and understanding of carcinoma development in transplantation patients and the general population as well.

Abstract

Immunosuppressive therapy after solid organ transplantation leads to the development of cancer in many recipients. Analysis of the occurrence of different types of de novo carcinomas in relation to specific immunosuppressive drugs may give insight into their carcinogenic process and carcinogenesis in general. Therefore, a systematic search was performed in Embase and PubMed. Studies describing over five de novo carcinomas in patients using immunosuppressive drugs after solid organ transplantation were included. Incidence per 1000 person-years was calculated with DerSimonian–Laird random effects model and odds ratio for developing carcinomas with the Mantel–Haenszel test. Following review of 5606 papers by title and abstract, a meta-analysis was conducted of 82 studies. The incidence rate of de novo carcinomas was 8.41. Patients receiving cyclosporine developed more de novo carcinomas compared to tacrolimus (OR1.56, 95%CI 1.00–2.44) and mycophenolate (OR1.26, 95%CI 1.03–1.56). Patients receiving azathioprine had higher odds to develop de novo carcinomas compared to mycophenolate (OR3.34, 95%CI 1.29–8.65) and head and neck carcinoma compared to tacrolimus (OR3.78, 95%CI 1.11–12.83). To conclude, patients receiving immunosuppressive drugs after solid organ transplantation have almost a 20-fold increased likelihood of developing carcinomas, with the highest likelihood for patients receiving cyclosporine A and azathioprine. Looking into altered immune pathways affected by immunosuppressive drugs might lead to better understanding of carcinogenesis in general.

Toll-like receptors: role in dermatological disease

Toll-like receptors (TLRs) are a class of conserved receptors that recognize pathogen-associated molecular patterns (PAMPs) present in microbes. In humans, at least ten TLRs have been identified, and their recognition targets range from bacterial endotoxins to lipopeptides, DNA, dsRNA, ssRNA, fungal products, and several host factors. Of dermatological interest, these receptors are expressed on several skin cells including keratinocytes, melanocytes, and Langerhans cells. TLRs are essential in identifying microbial products and are known to link the innate and adaptive immune systems. Over the years, there have been significant advances in our understanding of TLRs in skin inflammation, cutaneous malignancies, and defence mechanisms. In this paper, we will describe the association between TLRs and various skin pathologies and discuss proposed TLR therapeutics.