Pseudo-NRBC in the Mindray BC-6800Plus analyzer: A clue for diagnostic anticipation of fungemia. Experimental and preliminary clinical reports.

Introduction: Candidemia can be a significant cause of death in immunosuppressed or debilitated patients particularly. Abnormalities of the instrumental cytograms of some hematological analyzers, such as Mindray BC-6800Plus, can be related to circulating Candida. We studied the possible diagnostic usefulness of this information.

Methods: A fungal bloodstream infection has been simulated by adding aliquots of Candida albicans, Candida parapsilosis, and Candida glabrata to 75 leftovers and anonymized peripheral blood samples. Cytographic abnormalities like those of experimental samples were used to select patients with possible fungemia. The microscopic review of peripheral blood smears constituted the confirmatory method.

Results: In all experimental samples, the various Candida types caused pseudo-NRBC and morphological abnormalities of WNB and DIFF cytograms. Circulating blastospores, free or engulfed by neutrophils, were the microscopic findings in the peripheral blood smears. In the clinical verification, 72 patients were recruited based on the presence of an evocative cluster in the WNB and DIFF cytograms. The microscopic review of 39 out of 72 samples was positive for NRBC. According to blood cultures, light microscopy revealed fungal forms of several Candida or non-Candida types in the remaining 33 samples. Nine of these cases were not yet known to suffer from bloodstream infection.

Conclusions: Although further confirmatory clinical studies are required for these diagnostic abilities, the BC 6800Plus cytographic abnormalities related to fungemia have proven helpful in rapidly monitoring persistent fungemia in already diagnosed patients. In unknown or undiagnosed cases, they could be the trigger point for the subsequent diagnostic-therapeutic pathway.