Efficacy of plasma exchange with a high dose of acyclovir for disseminated varicella infection

In individuals treated with immunosuppressive therapies, the varicella-zoster virus (VZV) infection can become disseminated and lead to a life-threatening condition. There is currently no established treatment strategy for this life-threatening condition. Here, we describe a case where plasma exchange (PE) with a high dose of acyclovir (ACV) ameliorated the severe effects, including VZV-hemophagocytic lymphohistiocytosis (VZV-HLH) and disseminated intravascular coagulation (DIC), in a 9-year-old girl with steroid-dependent nephrotic syndrome. This 9-year-old girl experienced frequent relapse steroid-dependent nephrotic syndrome. She had been treated with steroids, tacrolimus, mizoribine, and rituximab. She had not previously received a varicella vaccine. She was admitted with only one vesicular rash. At admission, a serum test revealed 1.6 × 10⁶ copies/mL of VZV DNA. The patient rapidly developed VZV-HLH and DIC. A combination of a high dose of ACV, immunoglobulin, and steroid pulse therapy could not improve these severe complications. Therefore, PE was applied. PE with a high dose of ACV successfully reduced serum VZV DNA from 7.5 × 10⁶ to 2.8 × 10⁴ copies/mL. This reduction in the VZV DNA copy number suggested that the combination of PE and a high dose of ACV was effective in treating a disseminated VZV infection. To the best of our knowledge, this is the first report showing that PE with a high dose of ACV ameliorated the severe complications of disseminated VZV by reducing the VZV DNA copy number.