Prospective Study of Post-Transplant Microangiopathy in Allogeneic and Autologous Stem Cell Transplantation.

Thrombotic thrombocytopenic purpura-hemolytic uremic syndromes (TTP-HUS) have been described as specific sequelae following stem cell transplantation (SCT).Twenty-two patients undergoing autologous SCT and thirty-three patients undergoing allogeneic stem cell transplantation were prospectively evaluated on days 0, 7, 14, 30, 60, 90, 120 following SCT for the development of Post-Transplant Microangiopathy (PTM) based upon a rising lactic dehydrogenase level and percent fragmented cells (FC). The protocols were approved by the Institutional Review Board of the Western Pennsylvania Hospital where the studies were performed. The grades of PTM were based upon the criteria described by Zeigler et al, Bone Marrow Transplant, 1995) as follows: Grade 0: Normal LDH level and normal percentage fragmented cells (0–1.2%), Grade 1: Increased Fragmented Cells (FC) with normal LDH level, Grade 2: Increased LDH level that is rising with 1.2–4.8% FC, Grade 3: Increased LDH level with 4.9–9.6% FC and Grade 4: Increased LDH level with >9.6% FC. The data is shown below in tabular form. These results indicate that almost all patients have increased fragmented cells following both autologous and allogeneic SCT. The median percent fragmented cells in both allogeneic and autologous SCT patients without evidence for PTM was 1.4% with a range of 0–5.2% Moreoeve the LDH level x ULN was 0.7 with a range of 0.5–1.8 x ULN in patients without evidence for PTM. The table below shows the data for the development of PTM in both allogeneic and autologous SCT patients with regard peak grade. Only two autologous patients had no increase in FC. The Grade of PTM was significantly lower in the autologous SCT patients compared to the allogeneic SCT patients. The table below lists the grades of PTM and the day of the peak Grade of PTM in both types of SCT patients. The Grades of PTM, peak LDH level and highest percent FC were higher in the allogeneic SCT patients. Eleven of twenty-two (50%) of the autologous SCT patients compared to thirty/thirty-three (91%) of the allogeneic SCT patients (p <0.001) had evidence for PTM (grades 2 to 4).