The added value of peripheral blood cell morphology in the diagnosis and management of infectious diseases—part 1: basic concepts

Abstract

As automated blood cell analysers and sophisticated diagnostic technologies become widespread, requests for peripheral blood smear (PBS) examination--for the diagnosis of infectious diseases--diminish. Yet, PBS examination can provide rapid and invaluable information on infection--host susceptibility, aetiology, severity, and systemic impact. Besides direct visualisation of certain microorganisms (for example, Plasmodium, Ehrlichia), PBS examination may detect characteristic footprints left by various infections on the morphology of blood cells, thus yielding the cytologic clues of the disease (for example, Döhle bodies, haemophagocytosis). Additionally, PBS examination may disclose certain infection predisposing conditions (for example, May-Hegglin anomaly, hyposplenism), and several infection related haematological and systemic complications. Combined with a careful medical history and physical examination data, all this information may yield a speedy diagnosis, a rationalised diagnostic work-up, and timely initiation of treatment. The intention of the following review is to highlight the value of PBS, and recommend that PBS examination should be fostered in the diagnostic work-up of infectious diseases.

Delayed activation of host innate immune pathways in streptozotocin‐induced diabetic hosts leads to more severe disease during infection with Burkholderia pseudomallei

“…3d), indicating a delay in triggering the STZ-diabetic host innate immune response to acute B. pseudomallei infection compared with the infected normoglycaemic mice. 18 Moreover, several blood cell abnormalities, including monocyte vacuolization, Pseudo Pelger, hypersegmentation of neutrophil nuclei and Rouleaux formation frequently seen in serious bacterial infections 22,23 were also seen in the blood samples at 42 hr p.i. (Fig.…”

Anémie hémolytique chez l’adulte : principales causes et démarche diagnostique

“…Certains pathogènes peuvent déclencher des hémolyses par une action directe sur les GR [33,34]. L'agent infectieux le plus fréquemment responsable d'AH est de loin le Plasmodium (type Falciparum, Vivax ou Ovalae), à évoquer systématique-ment en contexte fébrile au retour d'une zone d'endémie.…”

The added value of peripheral blood cell morphology in the diagnosis and management of infectious diseases—part 2: illustrative cases

“…Toxic granulation, cytoplasmic vacuolisation and Döhle bodies are characteristic changes in neutrophil morphology that signal bacterial infection. Moreover, the presence of Döhle bodies is considered to be one of the earliest morphological indicators of sepsis 1 2. In this case, neither the clinical presentation nor the total leucocyte and thrombocyte counts could have helped in elucidating sepsis.…”

“…Functional a/hyposplenia may exist as a hidden condition accompanying several systemic diseases 1 3. In these settings, PBS examination is most rewarding, providing sensitive keys for diagnosis.…”