[Findings obtained by the analyses of unexpected abnormal laboratory data]

As the final lecture of Clinical Laboratory Medicine in Fukushima Medical University, I showed some of our findings obtained by the analyses of unexpected laboratory data. Most of these unexpected or unusual data were first noticed by laboratory staffs in charge. Items mentioned were; 1) false negative reaction of immunological fecal occult blood test, induced by the contact of hemoglobin with toilet sanitizers or detergents, 2) highly elevated serum K level, induced by the cold storage of whole blood, 3) false positive reactions in ELISA, induced by the aggregated IgG developed by the heat-pretreatment of sera, 4) panic values developed by the regurgitation of EDTA blood, 5) markedly low values due to the non-mixing of frozen thawed serum sample, 6) precision of the bleeding time in earlobes, and 7) differences in capillary blood glucose levels among forearm, palm and fingers. In the analyses of 6) and 7), the methodology of quality assurance could be introduced, although we realized the difficulty in examining in our physical body. Every issue examined is practically important, and laboratory staffs including physicians should pay more attention on the unexpected laboratory data and know why and how the data are produced.