Novel Protocol for Rapid Desensitization of Melphalan in a 5-Year-Old Boy Undergoing Conditioning for Hematopoietic Stem Cell Transplantation: A Case Report

Hematopoietic stem cell transplantation is a potentially life-saving therapy under certain conditions. Hypersensitivity reaction to chemotherapeutic drugs may interfere with this treatment. Griscelli syndrome type 2 is a rare autosomal recessive disease characterized by hypopigmentation of skin and hair, causing silver gray hair; this disease may develop a fatal condition called hemophagocytic lymphohistiocytosi. The main curative treatment for hemophagocytic lymphohistiocytosi is hematopoietic stem cell transplantation. Melphalan is an important drug in hematopoietic stem cell transplantation preparation regimen. This drug is only stable for 60 minutes following reconstitution with normal saline. There is a recommended 12- to 20-step desensitization protocol for moderate to severe hypersensitivity reaction to chemotherapeutic drugs. However, due to the short term stability of melphalan, this protocol cannot be employed in desensitization. In this case report, we presented a novel protocol for rapid desensitization of melphalan in a 5-year-old boy with immediate, moderate to severe hypersensitivity reaction, during hematopoietic stem cell transplantation. To obtain 50 mg total melphalan , we prepared solutions of drug in two bags; one with 12.5mg in 35 cc normal saline, and other with 25 mg in 35 cc normal saline. Each solution was infused during 60 minutes by incremental infusion rate, and the total of 50 mg melphalan was successfully infused.