Two unusual cases of autologous HSCT related TMA with kidney injury.

Kidney injury caused by transplant-associated thrombotic microangiopathy (TA-TMA) in patients who underwent allogeneic hematopoietic stem cell transplantation (allo HSCT) is relatively frequent. However, it is rarely reported in patients undergoing autologous HSCT (aHSCT). There are a few studies reported that TA-TMA could occur in pediatric patients undergoing aHSCT, but the condition in adult patients is rarely described. Furthermore, almost all the patients who suffered from TA-TMA developed typical and severe manifestations which should be treated with aggressive target therapy. Nevertheless, we presented two cases of kidney injury caused by TA-TMA after aHSCT with specific clinical features. Case 1, a 33-year-old Chinese male diagnosed with Hodgkin's lymphoma developed TA-TMA-associated kidney injury 4 months after transplantation. Case 2, a 49-year-old Chinese female with central nervous lymphoma developed TA-TMA-related kidney injury 3 months after transplantation. Both patients presented "mild" and atypical features of TA-TMA and their kidney function was managed effectively with low-dose prednisone therapy. TA-TMA related kidney injury can occur in patients who underwent aHSCT. Patients with TA-TMA could develop atypically "mild" features. Low-dose prednisone may be effective in place of routine eculizumab treatment regimen. We recommend that clinicians prompt an investigation for TA-TMA in patients presenting kidney injury in the background of aHSCT to facilitate early diagnosis.