Evaluation of automated hematology analyser: Mindray BC-6800 plus as a screening tool for diagnosing malaria

Background: Malaria is one of the major health problems of developing and tropical countries like India, causing huge financial burden also. Smear examination for diagnosis is a routine and cost-effective method for diagnosis. CBC is one the most commonly ordered test in clinical practice. The Mindray BC-6800 plus haematology analyser provide dedicated flag of “Infected RBC?” for suspected malaria while analysing CBC. Present study attempts to evaluate whether CBC done on BC-6800 plus can serve as an aid for malaria screening and diagnosis.Methods: Prospective study of 30077 cases was carried out where thick and thin smear examination done by experienced microscopists and CBC was analysed on BC- 6800 plus analyser.Results: Total 323 cases were found to be positive for malaria by smear examination, out of which 285 were of P. vivax and 38 were of P. falciparum malaria. Sensitivity of 88.24%, specificity of 99.21%, PPV of 54.70%, NPV of 99.87% for Infected RBC flag for all cases of malaria. For P. vivax malaria cases analyser provided highest sensitivity of 99.65% with NPV of nearly 100%, however P. Falciparum malaria cases analyser produced sensitivity of 2.63% only. In P. vivax cases present study found very good correlation between InR count and parasite load under microscope. Present study also evaluated interference of parasitized red cells in differential count causing falsely elevated neutrophils and/or eosinophils.Conclusions: By lowering threshold for “Infected RBC?” flag to 0, BC-6800 plus can serve as an excellent screening tool especially for P. vivax malaria

Accidental detection of clinically silent compound heterozygous Hb D Punjab/Hb Q India while analyzing HbA1c by high performance liquid chromatography

HbA1c is routinely prescribed investigations for diagnosing and monitoring diabetes and high-performance liquid chromatography (HPLC) is preferred method which is also able to identify presence of hemoglobin variant. A case was encountered where presence of variant hemoglobin was indicated. On further investigation with three different instruments, diagnosis of compound heterozygous Hb D Punjab/Hb Q India was made. The chromatogram on Bio-Rad D10 showed Hb D Punjab (ααββHbD Punjab)-29.89% at 3.96 minutes retention time (RT), Hb Q India (ααHbQ Indiaββ) -9.5% with 4.45 minutes RT, hybrid of HbQ India/Hb D Punjab (ααHbQ IndiaββHbD Punjab)-6% with 4.66 minutes RT, Hb A2 (ααδδ) was 2.5% and Hb A (ααββ) was 52.2%. Analysis done on Bio-Rad variant V-II confirmed these findings. Analysis done on Sebia capillary electrophoresis revealed major peak of 50.9% in zone 9/Z(A) constituted by Hb A, second peak of 39.8% in zone 6/Z(D) constituted by co-elution of Hb D and Hb Q India, third peak of 8.8% in zone 3-4/Z(A2-C) constituted by co-elution of Hb A2 and hybrid of Hb D Punjab/Hb Q India and a fourth peak of 0.5% in zone 1 representing Hb A2HbQ India (ααHbQ Indiaδδ). Ideally variants detected while analyzing HbA1c should be further investigated for confirmation and result of which should be shared, discussed and the patient should be encouraged for screening of available family members for relevant variant hemoglobin. Combination of cation exchange HPLC and capillary electrophoresis in this case was sufficient to arrive at conclusion

High prevalence of alpha thalassemia in the tribal community of the western part of India! Reality or myth? Can simple hematology parameters; MCV and MCH act as screening tools at birth?

Background: The majority of adult tribal subjects in the western part of India, show microcytic hypochromic red cells, and borderline anemia with a normal iron profile, suggesting a high prevalence of thalassemia in this population. Methods: The current study was designed to perform qualitative (to screen for Hb Bart’s) and quantitative (to estimate percentage of Hb Bart’s) hemoglobin electrophoresis with modification of the method, to evaluate the prevalence of α thalassemia and to determine gene frequency of α+ thal gene. Furthermore, the present study also aimed to evaluate common hematology parameters like MCV and MCH as screening tools to suspect α thalassemia at birth. Results: Based on hemoglobin electrophoresis, the prevalence of α thalassemia in all its forms was found to be 66.66%. The estimated gene frequency for α+ thal was found to be 0.7453 and based on that, the extrapolated prevalence of α thalassemia was 93.52% (55.55% homozygous and 37.97% heterozygous). MCV<100 fl and MCH<31 pg were found to be reliable screening tools to predict α thalassemia at birth in full-term uncomplicated pregnancy. Conclusions: Tribal community in the western part of India bears a very high prevalence of α thalassemia, it’s a reality and not a myth. Simple hematological parameters like MCV (<100 fl) and MCH (<31 pg) measured at birth can prove to be cost-effective surrogate markers for α thalassemia. Large scale study using confirmatory genetic analysis is required to validate the findings.