Contributions
Abstract: PB1968
Type: Publication Only
Background
Vitamin B12 deficiency induced megaloblastic anemia is diagnosed by complete blood count (CBC) parameters including RBC indices such as mean corpuscular volume (MCV), red cell distribution width-co-efficient of variation and standard deviation (RDW-CV, RDW-SD).Platelet indices such as mean platelet volume (MPV), platelet distribution width (PDW) and platelet large cell ratio (P-LCR) have been evaluated in thrombocytopenias of various etiologies.The present study aimed at exploring the reliability, diagnostic accuracy and utility of automated RBC and platelet parameters in evaluating vitamin B12 deficiency induced anemia and thrombocytopenia.
Aims
1.To evaluate MCV, RDW-CV and RDW-SD for their ability to detect vitamin B12 deficiency and related anemia.2.To evaluate the diagnostic accuracy of RDW-SD versus RDW-CV.3.To evaluate the discriminative function of platelet indices in thrombocytopenia of megaloblastic etiology in comparison with hypoproductive and hyperdestructive causes of thrombocytopenia and to correlate platelet indices with bone marrow megakaryocyte cellularity.
Methods
This retrospective analytical study included 100 cases with serum levels of vitamin B12<200 pg/ml. The hemoglobin, MCV, RDW-CV and RDW-SD were estimated by Sysmex XN-1000. Pearsons correlation was used for calculating the correlation of hematological parameters. Among 100 cases, 32 had thrombocytopenia and underwent bone marrow biopsy. Platelet indices in these 32 cases of thrombocytopenias of megaloblastic etiology were compared with platelet indices of 31 cases of marrow proven hypoproductive thrombocytopnias (aplastic anemia, hypoplastic anemia, acute leukemia) and 32 cases of hyperdestructive thrombocytopnias (Immune thrombocytopenia).Descriptive analysis was used and comparison of means in all the groups was done with one way ANOVA using Scheffe’s test. Categorical data was analyzed using Chi-square test.Platelet indices and bone marrow megakaryocytes were analyzed and correlated in each group. A p-value of less than 0.05 was considered statistically significant.
Results
Among 100 cases of vitamin B12 deficiency, elevated RDW-SD, RDW-CV and MCV were seen in 90%, 72% and 64% cases respectively. RDW–SD showed a strong negative correlation with serum vitamin B12 levels (p-value= 0.029) (p<0.05).RDW-CV showed a weak negative correlation with serum Vitamin B12 levels with an insignificant p-value of 0.58 (p>0.05). The sensitivity of RDW-SD, RDW-CV and MCV were 95%, 81% and 69.1% respectively for detection of anemia.
Mean values of platelet indices were higher (p<0.05) in hyperdestructive group [PDW(16.6fL), MPV(12.1fL), P-LCR(42.3%)] compared to the hypoproductive group [PDW(11.8fL), MPV(10.9fL), P-LCR(31.5%)].Mean values of PDW (14.7fL) and MPV (11.6fL) in megaloblastic group showed a higher value (p-value<0.05) than hypoproductive group but no significant difference was seen compared to hyperdestructive group (p-value>0.05).The mean P-LCR (37.4%) in megaloblastic group was intermediate from the other two groups (p-value<0.05).
Conclusion
RDW-SD is the most sensitive discriminant function even when MCV is normal despite vitamin B12 deficiency, since so far all the attention is being given to MCV as the earliest hematologic indicator of vitamin B12 deficiency. Platelet indices are of significant discriminative value in differentiating the various causes of thrombocytopenias. Both hypoproduction and ineffective thrombo-poiesis are the underlying pathomechanisms in megaloblastic thrombocytopenia as evidenced by the marrow findings and platelet indices.
Session topic: 29. Enzymopathies, membranopathies and other anemias
Keyword(s): Anemia, Diagnosis
Abstract: PB1968
Type: Publication Only
Background
Vitamin B12 deficiency induced megaloblastic anemia is diagnosed by complete blood count (CBC) parameters including RBC indices such as mean corpuscular volume (MCV), red cell distribution width-co-efficient of variation and standard deviation (RDW-CV, RDW-SD).Platelet indices such as mean platelet volume (MPV), platelet distribution width (PDW) and platelet large cell ratio (P-LCR) have been evaluated in thrombocytopenias of various etiologies.The present study aimed at exploring the reliability, diagnostic accuracy and utility of automated RBC and platelet parameters in evaluating vitamin B12 deficiency induced anemia and thrombocytopenia.
Aims
1.To evaluate MCV, RDW-CV and RDW-SD for their ability to detect vitamin B12 deficiency and related anemia.2.To evaluate the diagnostic accuracy of RDW-SD versus RDW-CV.3.To evaluate the discriminative function of platelet indices in thrombocytopenia of megaloblastic etiology in comparison with hypoproductive and hyperdestructive causes of thrombocytopenia and to correlate platelet indices with bone marrow megakaryocyte cellularity.
Methods
This retrospective analytical study included 100 cases with serum levels of vitamin B12<200 pg/ml. The hemoglobin, MCV, RDW-CV and RDW-SD were estimated by Sysmex XN-1000. Pearsons correlation was used for calculating the correlation of hematological parameters. Among 100 cases, 32 had thrombocytopenia and underwent bone marrow biopsy. Platelet indices in these 32 cases of thrombocytopenias of megaloblastic etiology were compared with platelet indices of 31 cases of marrow proven hypoproductive thrombocytopnias (aplastic anemia, hypoplastic anemia, acute leukemia) and 32 cases of hyperdestructive thrombocytopnias (Immune thrombocytopenia).Descriptive analysis was used and comparison of means in all the groups was done with one way ANOVA using Scheffe’s test. Categorical data was analyzed using Chi-square test.Platelet indices and bone marrow megakaryocytes were analyzed and correlated in each group. A p-value of less than 0.05 was considered statistically significant.
Results
Among 100 cases of vitamin B12 deficiency, elevated RDW-SD, RDW-CV and MCV were seen in 90%, 72% and 64% cases respectively. RDW–SD showed a strong negative correlation with serum vitamin B12 levels (p-value= 0.029) (p<0.05).RDW-CV showed a weak negative correlation with serum Vitamin B12 levels with an insignificant p-value of 0.58 (p>0.05). The sensitivity of RDW-SD, RDW-CV and MCV were 95%, 81% and 69.1% respectively for detection of anemia.
Mean values of platelet indices were higher (p<0.05) in hyperdestructive group [PDW(16.6fL), MPV(12.1fL), P-LCR(42.3%)] compared to the hypoproductive group [PDW(11.8fL), MPV(10.9fL), P-LCR(31.5%)].Mean values of PDW (14.7fL) and MPV (11.6fL) in megaloblastic group showed a higher value (p-value<0.05) than hypoproductive group but no significant difference was seen compared to hyperdestructive group (p-value>0.05).The mean P-LCR (37.4%) in megaloblastic group was intermediate from the other two groups (p-value<0.05).
Conclusion
RDW-SD is the most sensitive discriminant function even when MCV is normal despite vitamin B12 deficiency, since so far all the attention is being given to MCV as the earliest hematologic indicator of vitamin B12 deficiency. Platelet indices are of significant discriminative value in differentiating the various causes of thrombocytopenias. Both hypoproduction and ineffective thrombo-poiesis are the underlying pathomechanisms in megaloblastic thrombocytopenia as evidenced by the marrow findings and platelet indices.
Session topic: 29. Enzymopathies, membranopathies and other anemias
Keyword(s): Anemia, Diagnosis