The preliminary study of delta checks for immunoglobulins and complements in the clinical laboratory

Background: To determine delta check limits for immunoglobulins and complements in outpatients and inpatients based on patient data and biological variation due to the lack of relevant studies. Methods: Patient data for IgA, IgG, IgM, IgE, C3 and C4 from January 1st, 2022 to December 31st, 2023 was collected from laboratory information system (LIS) in our clinical laboratory of wuhan union hospital, which includes both outpatients and inpatients. The delta difference (DD), delta percent change (DPC) and reference change value (RCV) were calculated based on patient data and biological variation. Results: For DDs, there are significant differences between outpatients and inpatients in C4, IgE, IgG, and IgM. For DPCs, the corresponding analytes which are significantly different are C3, C4, IgE, IgG, and IgM. Two sources of CVI to calculate the RCV of IgA, IgG, IgM, C3 and C4 were applied in this study, which revealed that two kinds of RCVs based on different biological variation databases are similar to each other, but both were smaller than delta check limits based on patient data, except for C4. Conclusions: The delta check is a useful tool to monitor potential errors which may occur in total testing process. We hope our findings could be helpful for future studies focused on delta checks in immunological analytes. Keywords: Delta check; Patient data; Biological variation; Immunoglobulins; Complements