Modified Treatment for Pediatric Multisystemic Histiocytosis during Sars-Cov2 Lockdown. Series of Cases

ABSTRACT

Purpose: Backbone treatment ofmultisystemic histiocytosis (MS-LCH) is steroids in combination with chemotherapy (vinblastine/vincristine and/or cytarabine). This approach requires a central venous access (CVA) placement because of the possibility of citostatic extravasation and length of treatment. SARS-CoV2 lockdown forced us to adapt standard treatment in order to skip CVA placement, use of available cytostatics, reduce toxicity and hospital visits. We report here our experience using a modified treatment (MT) Methods:Series of 4 pediatric patients (pt) of MS-LCH treated during 2020 with a MT. Induction Oral Methylprednisone 40 mg/m2 daily for 4weeks, tapering for 2weeks, and subcutaneous/intravenous cytarabine 100 mg/m2/day for 4 days, day 1-14. Evaluation at 6th week. If NAD or ADB, continuation treatment Methylprednisone 40 mg/m2/day for 5 days every 15 days and subcutaneous/intravenous cytarabine 100 mg/m2/day for 4 days every 3 weeks. Clinical and hematologic evaluation every 3 weeks. We studied the presence of circulating CD207+/CD1a+ cells (cc) by flow cytometry Results:Female 3pt. Identical twins (pt#1,2). Age at diagnosis 7, 7, 11 and 29 months. Involvement skin, lymph nodes and hematopoietic (pt#1,2,3,4), ear (pt#2,3,4), bone (pt#3), hepatosplenomegaly (pt#4) All pt achieved ADB after 6 weeks of treatment. Reactivation 1pt because of non-adherence to treatment. No grade 3/4 toxicity. COVID infection with mild symptoms (pt#1,2). Status all alive with NAD at 2 years (pt#1,2) and 1 year (pt#3,4) of treatment. All pt started with a low score for cc and increased them with the treatment in negative trend to their clinical status Conclusion(s) This MT was feasible to treat pt with MS-LCH during the SAR-Cov2 lockdown, even those with risk organ involvement.We were able to skip CVA and reduce toxicity. Treatment could be restraining cc migration to the lesions.