Is Homemade Pooled Plasma the Answer to Cost-Effective Coagulation Control?

Using control plasma is crucial in coagulation testing because it ensures the accuracy and reliability of lab results. By comparing patient samples against a dependable control like a normal plasma pool, laboratories can guarantee the precision required for effective clinical practice, especially when conducting tests like the activated partial thromboplastin time (TTP) test. This is vital for detecting deficiencies or inhibitions in coagulation factors, monitoring heparin therapy, and identifying lupus anticoagulants. Without reliable controls, the validity of diagnostic and therapeutic decisions can be compromised.

To prepare homemade plasma pools, plasma samples are collected from individuals with no known bleeding disorders, ensuring that samples showing signs of hemolysis, lipemia, or icterus are excluded to maintain the pools' integrity. Each day, fresh pools are created; for example, a P5 pool involves mixing 500 µl of plasma from each of five selected samples. The goal is to minimize variability and provide a consistent control material. These pools, such as P5 and P20, are then tested alongside commercial controls using systems like the Dade-Behring BCS® coagulation system.

To validate the use of homemade plasma pools, researchers used several statistical methods. Variance analysis was applied to assess the overall variability within and between the different plasma pools (P5 and P20) and the commercial control (AP). The Tukey test was specifically used to evaluate and pinpoint significant differences between these groups. These methods ensure that any conclusions drawn about the reliability of homemade plasma pools are statistically sound, rigorously testing whether they can serve as reliable substitutes for commercial controls. The time ratios are also analyzed to check for discrepancies.

For smaller labs, preparing a homemade plasma pool offers significant cost-saving advantages. By creating their own normal controls, labs reduce their reliance on expensive commercial controls, which can strain limited budgets. Moreover, homemade plasma pools can be more representative of the lab's specific patient population, potentially leading to more accurate and relevant results. This approach aligns with the broader trend in healthcare to optimize resources while maintaining high standards of quality control in essential diagnostic procedures like TTP testing. However, standardization and validation remain critical to ensure consistency.

While homemade plasma pools offer cost and relevance advantages, potential limitations exist. Consistency in preparation is critical; variations in sample collection, pool composition, and testing procedures can introduce variability, affecting reliability. Unlike commercial controls, homemade pools lack standardized manufacturing processes and quality control measures, potentially compromising accuracy. Furthermore, comprehensive validation is necessary to ensure homemade pools perform comparably to commercial controls, requiring rigorous statistical analysis and ongoing monitoring. Smaller labs might face resource constraints in performing these validations, impacting confidence in their homemade controls for TTP testing. Factors like the number of plasmas included in the pool (e.g., P5 versus P20) can also influence performance, as demonstrated by studies analyzing TTP values and time ratios between different pool sizes and commercial controls.