LRA by ELISA/ACT Tests Are Highly Reproducible; Cell Size Tests Are Not.

There is a fundamental difference between LRA by ELISA/ACT true lymphocyte response assay (LRA) and ALCAT cell size test. A common misconception is that change in white blood cell morphology size/volume ratio assessed with a Coulter-type size analyzer is the same as a

true LRA. This is not true and here is why:

1. Method

The LRA by ELISA/ACT testing methodology performs a true cell culture. The tests identify only lymphocytes by direct morphology and not by size. This is because there are many ten microns particles that are not lymphocytes. These particles can be mistaken for lymphocytes in a particle size test such as the ALCAT testing that assumes size tells all. Since red cell stacks (rouleaux), platelet clumps and debris from dendritic cells are often in the same ten micron size, many false positives appear to occur if one concludes that all particles of that size are lymphocytes.

A further technical point: Coulter type counters use linear amplifiers. For smaller particle sizes, you need a log amplifier to get more accurate results. Beyond that, you need some additional probe to determine if the particle of that size has anything to do with the immune system since there are lots of particles of the same size that are due to cell destruction or to activation of blood clotting.

The ALCAT methodology uses a lysing agent in attempt to rid the test sample of RBCs. This is a hypertonic solution that leaves much variable debris in the ten microns size range after the red cells are lysed. In people with hypercoagulation syndromes, activation of blood clotting can

occur to a variable degree.

2. Reproducibility and clinical predictive significance of tests results

LRA by ELISA/ACT tests utilize a true ex vivo autologous cell culture that looks at the immune responses to lymphocytes. The reliability and accuracy that the technology provides is far superior to other techniques, including cell size tests. A recent research article published in the Natural Medicine Journal1showed 34% accuracy for ALCAT testing for split samples. Independent research by ELISA/ACT Biotechnologies demonstrates 97.6% accuracy in

comparison (see Figure 1, below).