STANDARDIZED METHODS FOR IN-HOUSE SEPARATION OF A BLOOD PRODUCT FOR MULTIPLE USE

A novel modified thaw-siphon method for extracting cryoprecipitate: The Bokutoh-siphon method

BACKGROUND

Cryoprecipitate (CRYO) is neither produced nor supplied by the Japanese Red Cross Society. A novel CRYO extraction method established in-house by modifying a thaw-siphon technique was demonstrated in this study.

STUDY DESIGN AND METHODS

A pack of fresh frozen plasma was thawed and equally divided into two bags for CRYO extraction by different methods. CRYO was extracted from the blood plasma using a standard centrifugation method and our modified thaw-siphon method (Bokutoh-siphon method; B method). The two different CRYOs extracted were analyzed to compare the differences in the amount of fibrinogen recovered, clotting factors extracted, and clotting activity.

RESULTS

The amount of fibrinogen in the CRYO extracted using the B-siphon method was similar to that obtained using the standard method (recovery of fibrinogen: B-siphon method: 71.2% vs. standard method: 61.0%). The amount of clotting XIII factor extracted using the B-siphon method was significantly lower than those extracted using the standard method. On the other hand, clotting II, V factors, and C1q esterase inhibitor not concentrated in CRYO content from the B-siphon method were significantly higher than that from the standard method.

CONCLUSION

A new in-house CRYO preparation method was established by modifying a previously used thaw-siphon method. A coagulation factor-rich CRYO was extracted from plasma frozen at -40°C along with the first fraction of thawed plasma, without using a large-capacity refrigerated centrifuge for blood bags.

Use of potassium adsorption filter for the removal of ammonia and potassium from red blood cell solution for neonates

BACKGROUND

Ammonia in the plasma usually does not pass through the blood-brain barrier (BBB). However, it can affect the brain as a neurotoxin in neonates with anemia of prematurity. Excess intake of ammonia should therefore be restricted in conditions involving BBB breakdown, such as in premature neonates. A potassium adsorption filter (PAF) can remove not only potassium, but also ammonia from red blood cell (RBC) solution. PAF for neonates (PAF-n) has been recently introduced using small satellite packs. We evaluated the effects of PAF-n on the removal of ammonia and potassium from RBC solution in small satellite packs.

STUDY DESIGN AND METHODS

RBC solutions were obtained from the Japanese Red Cross Society. Two units of RBC solution (280 mL) were divided into four satellite packs (70 mL/pack). The RBC solution was passed through PAF-n (Kawasumi Laboratories Inc.) that was primed with saline (100 mL) before use. The concentrations of ammonia and potassium were measured in the solution before and after filtration (four samples of 10 mL each of filtered RBC solution) by Biomedical Laboratories.

RESULTS

Approximately 47 to 82 and 84% to 93% of ammonia and potassium were removed from the RBC solution, respectively, without dilution with saline.

CONCLUSION

PAF-n can remove ammonia and potassium from RBC solution in small satellite packs. PAF-n could therefore improve the clinical prognosis of neonates with poorly developed BBB by limiting the delivery of excess ammonia found in the RBC solution.