How old is too old? In vivo engraftment of human peripheral blood stem cells cryopreserved for up to 18 years - implications for clinical transplantation and stability programs.

BACKGROUND: Peripheral blood stem cells (PBSC) are commonly cryopreserved awaiting clinical use for hematopoietic stem cell transplant. Long term cryopreservation is commonly defined as five years or longer, and limited data exists regarding how long PBSC can be cryopreserved and retain the ability to successfully engraft. Clinical programs, stem cell banks, and regulatory and accrediting agencies interested in product stability would benefit from such data. Thus, we assessed recovery and colony forming ability of PBSC following long-term cryopreservation as well as their ability to engraft in NOD/SCID/IL-2Rγnull (NSG) mice. AIM: To investigate the in vivo engraftment potential of long-term cryopreserved PBSC units. METHODS: PBSC units which were collected and frozen using validated clinical protocols were obtained for research use from the Cellular Therapy Laboratory at Indiana University Health. These units were thawed in the Cellular Therapy Laboratory using clinical standards of practice, and the pre-freeze and post-thaw characteristics of the units were compared. Progenitor function was assessed using standard colony-forming assays. CD34-selected cells were transplanted into immunodeficient mice to assess stem cell function. RESULTS: Ten PBSC units with mean of 17 years in cryopreservation (range 13.6-18.3 years) demonstrated a mean total cell recovery of 88% ± 12% (range 68%-110%) and post-thaw viability of 69% ± 17% (range 34%-86%). BFU-E growth was shown in 9 of 10 units and CFU-GM growth in 7 of 10 units post-thaw. Immunodeficient mice were transplanted with CD34-selected cells from four randomly chosen PBSC units. All mice demonstrated long-term engraftment at 12 wk with mean 34% ± 24% human CD45+ cells, and differentiation with presence of human CD19+, CD3+ and CD33+ cells. Harvested bone marrow from all mice demonstrated growth of erythroid and myeloid colonies. CONCLUSION: We demonstrated engraftment of clinically-collected and thawed PBSC following cryopreservation up to 18 years in NSG mice, signifying likely successful clinical transplantation of PBSC following long-term cryopreservation.

Transfusion-related acute lung injury: a thrombotic thrombocytopenic purpura treatment-associated case report and concise review.

Blood products are frequently required immediately prior to, during, or just after an apheresis procedure. Transfusion-related acute lung injury (TRALI) is now the leading cause of transfusion-related mortality, surpassing ABO-incompatible hemolytic reactions. The reported incidence of TRALI varies but is estimated at 1 in 5,000 transfusions. The true incidence could be higher because of under-reporting and under-diagnosis. Plasma is the most frequently implicated blood product. While the pathogenesis of TRALI appears multifactorial, one contributing factor seems to be donor antibodies to cognate recipient neutrophil antigens. Biologically active neutrophil-priming substances may also play a role. New diagnostic criteria have recently been proposed to aid in the diagnosis of TRALI. We report a thrombotic thrombocytopenic purpura (TTP) treatment-associated case of TRALI and review the history, pathogenesis, diagnosis and management of this syndrome. Current risk reduction strategies are also discussed.

What are appropriate initial and salvage therapies for patients with thrombotic thrombocyopenic purpura (TTP)?

Although much has been learned about the pathophysiologic process of thrombotic thrombocytopenic purpura (TTP), both diagnostically and therapeutically, since its initial description by Moschowitz in 1924, its etiology and treatments remain, in many instances, problematic. Thrombotic thrombocytopenic purpura remains a rare entity whose etiology is usually unknown, but several drugs and infections have now been implicated in its development. Although treatment by plasma exchange has gained worldwide acceptance, the optimal exchange media is not known, nor the volume and duration of exchange therapy, not appropriate salvage therapies. Without the benefit of randomized controlled trials, its treatment, to a large extent, remains not evidence-based but "eminence-based", making the same mistakes with increasing confidence over decades.

Arsine toxicity treated with red blood cell and plasma exchanges.

BACKGROUND: Acute toxicity due to inhalation of arsine gas (AsH(3)) has no known antidote. Exchange transfusion may be beneficial, and dialysis is often required because arsine may cause acute intravascular hemolysis and renal failure. A patient with arsine toxicity has recently been treated by both red blood cell exchange (RBC-E) and plasma exchange (PE) therapy and our experience is reported. CASE REPORT: A 46-year-old man was accidentally and unknowingly exposed to arsine gas while observing an industrial procedure. Within 6 hours he developed fatigue, nausea, vomiting, and tingling in his extremities and voided dark urine. He quickly developed renal failure secondary to acute arsine toxicity (arsenic level, 1250 microg/L). Laboratory findings were a hematocrit level of 24 percent; blood urea nitrogen and creatinine, 84 and 5.5 mg per dL, respectively; bilirubin, 9.1 mg per dL; indirect bilirubin, 6.8 mg per dL; haptoglobin, less than 6 (normal, 30-200); and lactic dehydrogenase, 10,413 units per L (normal, 265-580). An emergent 1-vol RBC-E transfusion by continuous-flow method revealed dramatic black, grossly hemolyzed plasma. After two additional RBC-E and two PE and daily hemodialysis, he completely recovered over the course of 1 month. CONCLUSION: Patients with arsine toxicity resulting in intravascular hemolysis should receive RBC-E as soon as possible. In addition, PE may be beneficial in removing the components of RBC lysis and further reducing arsenic levels.

Myocardial infarction/injury is relatively common at presentation of acute thrombotic thrombocytopenic purpura: the Indiana University experience.

Although widespread vascular thrombosis is common in thrombotic thrombocytopenic purpura (TTP), there have been no prospective studies on the extent of injury to specific organs. Following successful resuscitation and plasma exchange of an index patient with widespread organ dysfunction, cardiogenic shock, and elevated cardiac troponin-I levels, we prospectively studied and identified 2 more individuals (of 10 consecutive patients) with evidence of myocardial injury/infarction at presentation of acute TTP. These data suggest that cardiac troponin-I measurements should be considered during initial evaluation of all patients with acute TTP.