Elevated procalcitonin and C-reactive protein as potential biomarkers of sepsis in a subpopulation of thrombotic microangiopathy patients.

Thrombotic microangiopathy (TMA) comprises a group of microvascular thrombosis syndromes associated with multiple pathogenic factors. Deficient activity of ADAMTS13 is a pathogenic factor in a subset of TMA patients that provides a strong rationale for plasma exchange treatment. However, the subset of TMA patients with normal ADAMTS13 activity remains a heterogeneous group of patients in which the appropriate treatment is not well understood. In addition to the common forms of TMA thrombotic thrombocytopenic purpura and the hemolytic uremic syndrome, the differential diagnosis of TMA may include sepsis, autoimmune disorders, and disseminated intravascular coagulation. Optimal treatment of TMA depends on timely recognition of treatable pathogenic factors. We hypothesized that sepsis is a rapidly identifiable pathogenic factor in a subset of TMA patients. To test this hypothesis, we retrospectively measured the rapid biomarkers of sepsis C-reactive protein (CRP) and procalcitonin (PCT), in a repository of pretreatment plasma samples from 61 TMA patients treated with plasma exchange. Levels were analyzed in 31 severely ADAMTS13-deficient and 30 ADAMTS13-normal patients. None of the 31 patients with severe deficiency of ADAMTS13 had elevated PCT. However, 11 of 30 (37%) non-ADAMTS13-deficient patient samples were strongly positive for PCT. These patient samples also had a >10-fold higher median CRP level than patients with normal PCT. We conclude that rapid assays may help identify sepsis in a subset of TMA patients.

Improved peripheral blood stem cell collection following plasma exchange in a patient with elevated viscosity and coagulopathy.

We report a case of improved CD34+ cell yields from peripheral blood stem cell (PBSC) collection following therapeutic plasma exchange (TPE) in a patient with elevated viscosity and coagulopathy. The patient was a 46-year-old male diagnosed with IgM lambda multiple myeloma that was largely unresponsive to standard chemotherapy. He had coagulopathy due to lymphoproliferative disease-associated acquired von Willebrand Factor (vWF) deficiency. The patient underwent two rounds of PBSC collections over 3 consecutive weeks (five total collections) prior to planned tandem transplant for multiple myeloma. Both rounds resulted in poor collections due to processing difficulties. It was decided to perform three TPEs daily immediately prior to attempting additional PBSC collections, to treat the patient's elevated viscosity and thereby potentially improve the efficiency of collections. Immediately following the three TPEs, two additional PBSC collections resulted in sufficient CD34+ cells to proceed to transplant. Lower IgM and/or viscosity levels present after the three TPEs likely permitted successful collection of stem cells.