Laboratory Identification of Cryoglobulinemia From Automated Blood Cell Counts, Fresh Blood Samples, and Blood Films

Abstract

Four cases showing different means to detect cryoglobulins are reported: effects on blood cell counts performed on 2 technologically different automated hematology instruments and microscopic features in fresh blood samples and on May-Grünwald-Giemsa-stained bloodfilms. These cases were chosen for their instructive value in depicting all artifacts associated with cryoglobulins. Laboratory recognition of the cryoglobulins is important to correct factitious results with automated blood cell counters, mainly pseudoleukocytosis and pseudothrombocytosis. Moreover cryoglobulin-induced laboratory artifacts may be the first factor prompting the assessment for cryoglobulinemia and the diagnosis of the underlying cause.

Spurious counts and spurious results on haematology analysers: a review. Part II: white blood cells, red blood cells, haemoglobin, red cell indices and reticulocytes

“…The presence of cryoglobulin was first reported as causing erroneous WBC counts (Emori, Bluestone & Goldsberg, 1973; Taft et al. , 1973; Haeney, 1976; Gulliani, Hyun & Gabaldon, 1977), but it also leads in many instances to spuriously elevated PLT counts, and at times to altered RBC counts or Hb measurements (cf., see Fohlen‐Walter et al. , 2002).…”

“…However, anomalies generated must be considered because they have some peculiar characteristics, and their recognition may be the first clue leading to the diagnosis of cryoglobulinaemia (Zandecki et al. , 1989; Fohlen‐Walter et al. , 2002).…”

Pseudoleukocytosis secondary to hepatitis C-associated cryoglobulinemia: a case report

“…The erythrocyte sedimentation readings at 20°C and 12°C underestimate the true ESR [7]. Pseudothrombocytosis [9] and pseudolymphocytosis [10] were even reported with doubling of the platelet counts.…”

Die kryoglobulinämische Vaskulitis

“…In Einzelfällen sind problematische Proteine,die entweder ein durch Wärme nicht wieder auflösbares Präzipitat bilden [18] oder sich in kalziumhaltigem Puffer auflösen,beschrieben. Bei der Erstellung von Blutbildern ergeben sich Hinweise auf eine Kryoglobulinämie durch Laborartefakte wie Pseudothrombozytose, Pseudoleukozytose und zytoplasmatische Einschlusskörperchen in Leukozyten [15,29] Histologie Die Diagnose der CV sollte durch eine Biopsie eines betroffen Organs gesichert werden. Typischerweise findet sich eine Immunkomplexvaskulitis kleiner Gefä-ße.…”