1. Abnormal WBC scattergram: A clue to the diagnosis of malaria
Sehgal Shivali, Sharma Sunita, Sethi Neha, Kushwaha Shivani, Chauhan Richa
Lady Hardinge Medical College, New Delhi
INTRODUCTION
Gold standard for diagnosis of malaria is demonstration of the parasite on the peripheral smear
CBC is a routine investigation in patients presenting with febrile illnesses
The present study assesses the use of WBC scattergram in suspecting the diagnosis of malaria
METHODS
119 cases of malaria were diagnosed by microscopic detection of parasite on PS from June 2011 to August 2011
Samples were analysed on Sysmex XT 2000i hematology autoanalyser
Hemogram findings along with WBC scattergram were assessed
Smears were reevaluated for degree of parasitemia
CONCLUSION
Abnormal WBC scattergram findings like graying of neutrophils and eosinophils, rightward shift of RBC ghosts, double neutrophil/eosinophil areas & block of DIFF parameters in a febrile patient alerts the pathologist to screen the PS for malarial parasite
WBC SCATTERGRAM FINDINGS
At least one of these findings was observed in 80% cases
No correlation with parasitemia was observed
DIFF FINDINGS
Block in DIFF parameters observed in 55% cases
DISCUSSION
WBC scattergram is plotted based on intensities of lateral scattered light and lateral fluorescent light
Malaria containing samples give anomalous scattergrams because of presence of birefringent hemozoin in WBCs leading to their misclassification
Reason for rightward shift of RBC ghost area is the increased RBC side scatter due to presence of hemozoin
Confluence of NEUTROPHILS & EOSINOPHILS
(54.6%)
Rightward shift of RBC ghost area (50%)
Graying of EOSINOPHIL & NEUTROPHIL groups (26%)
Graying of LYMPHOCYTE & MONOCYTE groups (5.04%)
Two NEUTROPHIL populations (13.4%)
Two EOSINOPHIL
populations (3%)
Two LYMPHOCYTE populations (0.8%)
Pseudoeosinophilia
(7.5%)
[E=15%:PS: E=1%]
ADVANTAGES
Pathologists perform a careful search on the PS even without clinical suspicion
Early diagnosis-↓ disease complications
Scattergrams can serve as a prognostic marker
CBC FINDINGS
WBC SCATTERGRAM FINDINGS
DISADVANTAGE
False Positive results d/t persistence of WBCs containing hemozoin pigment
P.vivax=109 cases
P.falciparum=10 cases
FUTURE PROSPECTS
? “MALARIA FLAG” on hematology autoanalysers
REFERENCES
Hanshield T et al. Parasitology today 2000;16(12):549-51
Huh J et al. Ann hematol 2005;84:400-2
Huh HJ et al. Ann hematol 2008;87:755-9