Plasma exchange for COVID-19 thrombo-inflammatory disease.

Severe COVID-19 disease is a hyperinflammatory, pro-thrombotic state. We undertook plasma exchange (PEX) to determine its effects on organ function and thrombo-inflammatory markers. Seven critically ill adults with severe COVID-19 respiratory failure (PaO2:FiO2 ratio < 200 mm Hg) requiring invasive or noninvasive ventilatory support and elevated thrombo-inflammatory markers (LDH >800 IU/L and D-dimer >1000 µg/L (or doubling from baseline) received PEX, daily, for a minimum of 5 days. No other immunomodulatory medications were initiated during this period. Seven patients matched for age and baseline biochemistry were a comparator group. Coagulation screening revealed no evidence of coagulopathy. However, von Willebrand Factor (VWF) activity, antigen and VWF antigen: ADAMTS13 ratio, Factor VIII and D-dimers were all elevated. Following 5 days of PEX, plasma levels of all the above, and ferritin levels, were significantly reduced (P < .05) while lymphocyte counts normalized (P < .05). The PaO2:FiO2 ratio increased from a median interquartile range (IQR) of 11.6 (10.8-19.7) kPa to 18.1 (16.0-25.9) kPa (P < .05). Similar improvements were not observed in controls. Acute kidney injury (AKI) occurred among five patients in the control arm but not in patients receiving PEX. PEX improved oxygenation, decreased the incidence of AKI, normalized lymphocyte counts and reduced circulating thrombo-inflammatory markers including D-Dimer and VWF Ag:ADAMTS13 ratio.

Is peripheral access for apheresis procedures underutilized in clinical practice?-A single centre experience.

BACKGROUND: The majority of reports regarding general vascular access choices for apheresis procedures argue that peripheral venous access should be considered first. However, the clinical reality appears to be different. While some procedures mandate central vascular access (e.g., therapeutic apheresis procedures in critically ill patients) and in some cases it is the patient's preference, we propose that the majority of elective procedures can be successfully performed peripherally. PURPOSE: To establish the feasibility and suitability of peripheral access for different apheresis procedures, undertaken in elective or emergency settings. METHODS: The choice of vascular access devices and cannulation sites were analysed retrospectively from all apheresis procedures performed between January 2014 and December 2015 at a single institution. RESULTS: Over 2 years a total of 3714 procedures were performed on 1061 patients. Absolute number of procedures (percentage) done peripherally: autologous and allogeneic hematopoietic progenitor cell harvest-400 (88%) and 458 (97%) respectively; mononuclear cell harvest-88 (93%); automated red cell exchange-1954 (80%); therapeutic plasma exchange-766 (26%); white blood cell depletion-48 (71%). Choice of vascular access for all procedures (absolute number [percentage]): peripheral and ultrasound-guided peripheral deep vein cannulation-2683 (72%); central venous catheter access: femoral-331 (9%); jugular-511 (14%); subclavian-2 (<1%); double-lumen port-187 (5%). Peripheral access in all apheresis procedures (emergency and elective) was 72%; for purely elective procedures this number increased to 80% to 97%, depending on the procedure. CONCLUSION: In our institution the majority of elective apheresis procedures are successfully performed using peripheral access.

Peripheral blood stem cell yield in 400 normal donors mobilised with granulocyte colony-stimulating factor (G-CSF): impact of age, sex, donor weight and type of G-CSF used.

Mobilised peripheral blood is now the main source of stem cells collected from normal donors. We report our experience of mobilising and collecting 400 normal healthy donors using standardised procedures and techniques. Target recipient doses were reached with one aphaeresis in 63% of donors and with two aphereses in 81% of donors. Approximately 2% of donors yielded such low progenitor values that they were termed 'poor mobilisers'. There were minor effects of donor age, weight and sex and where possible, larger male donors under the age of 55 years should be selected. Two forms of granulocyte colony-stimulating factor (G-CSF) were used at the same dose and no significant difference was seen in the yield of CD34+ cells collected/l of blood processed. However, a greater number of granulocyte-macrophage colony-forming cells were harvested using lenograstim (glycosylated G-CSF) compared with filgrastim (non-glycosylated G-CSF; P = 0.002). CD34+ cell yields were also measured halfway through the aphaeresis procedure. This was found to be highly predictive of final yield and facilitated distribution of the stem cell product to other centres. The observation that CD34+ yields did not decline in the second half compared with the first half of aphaeresis suggests that the circulating cell numbers are not static.