Many different parameters can affect the precision and reproducibility of a biological assay. Consequently, it is important to establish a robust assay that performs consistently in the hands of multiple investigators. The Table shows the results of one such study.
The results reported in this study highlight the testing of a panel of anti-IFN-β antibodies displaying varying neutralizing capacities. Of these, PAb 31410-1 exhibited the most potent neutralization capability and lowest CV rate. Our results also demonstrated that the NAb assay is highly reproducible, and produces comparable neutralization titers even when used by different investigators.
Inter-operator reproducibility is critical, as this would allow for direct comparison of patient results between multiple operators within one or more diagnostic laboratories. These initial studies are promising and warrant further expanded studies with MS patient serum samples to better determine the assay sensitivity, precision, and false-positive rate.
Clearly, the immune response in MS patients is not uniform. Individual variations in the types of T helper cells present, and the levels and potency of neutralizing anti-IFN-β antibodies present in patients can vary greatly and potentially impact the efficacy of IFN-β therapy.
The ability to accurately predict the likelihood of a given patient response to IFN-β therapy (i.e., not in the high IL-17/IFN-β MS subtype) would be of enormous clinical benefit given the high costs and potential side effects of continuous IFN-β therapy. Thus, having an assay that precisely and reproducibly evaluates the levels of neutralizing anti-IFN-β present in patient serum samples is a critical step toward achieving this goal.