Correlation of platelet indices in various disease groups with thrombocytopenia Tapasyapreeti Mukhopadhyay, Rupali Awale, Ratnaprabha Maji, Subhadra Sharma, A K Mukhopadhyay Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi Introduction & Background Table-1: Values of platelet indices in various disease category PLATELET INDICES CONTROL (n=30) NON MALIGNANT CONDITIONS (n= 259) MALIGNANT CONDITIONS (n=41) Mean Platelet count (per cumm) 252 (150-450) 60 (5-100) 30 (7-100) Plateletcrit 0.243 (0.106-0.486) 0.047 (0.003-0.120) 0.017 (0.005-0.088) Mean platelet volume (fL) 9.7 (8.0-11.9) 10.22 (5.2-14.9) 9.5 (7.6-12.8) Platelet distribution width (fL) 16.35 (15.6-17.8) 17.32 (13.8-20) 17.10 (13.3-19.6) Platelet parameters have been thought to be important in diagnosis of various diseases. They being mean platelet volume (MPV), pleteletcrit (PCT) and platelet distribution width (PDW), are readily available in the advanced hematological autoanalysers. They are inexpensive and simple to use This study was conducted to understand the relation of these indices in settings of thrombocytopenia. Aims and Objectives To correlate these platelet parameters, in various disease groups presenting with thrombocytopenia. Discussion Material and Methods Platelet distribution width amongst other platelet indices provided the most valuable information in our study as also shown by Reddy et al. (1) Borkataky et al. showed PDW can differentiate non-megaloblastic hypoproliferative category from both the destructive and megaloblastic thrombocytopenia category. (2) We also found PDW to vary inversely with platelet count and was statistically significant in settings of non-malignant conditions like chronic liver disease and settings of pancytopenia. (1,2) MPV varied inversely but non-linearly with the platelet count in normal individuals but in thrombocytopenic patient similar correlation was not observed, corresponding to a study by Karnad et al. (3) Higher MPV is also associated with the presence of cardiovascular risk factors, chest pain due to acute coronary syndrome, and adverse outcome after acute coronary syndrome. Results from studies evaluating MPV in patients with peripheral artery disease (4) MPV was increased in infections and cases of pancytopenia in our study; this could be explained by younger circulating forms due to marrow response in thrombocytopenia like shown in a study by Elsewefy et al. This study was a cross-sectional study conducted over a period of 2 months from April to May 2016 at AIIMS. A total of 300 in-patients with various diagnosis and platelet count <1lakh/cumm were included in the study. Control groups comprised of 30 healthy volunteers. 3ml of peripheral venous blood was collected in K2EDTA containing vacutainer and analysed within 2-6 hours on Beckman coulter LH-750 hematology auto analyser and reassessed by peripheral smear examination . Data was collected and analysed. Results Of the 300 blood specimens of thrombocytopenia analysed, 192/300 were males (64%) and 108/300 were females (36%) with male to female ratio 1.77:1. The age of patients ranged from neonate to 90 years, average age being 37 years. Non- malignant pathology were seen in majority of patients (86.33%) including infective, inflammatory etiology or had pyrexia of unknnown origin, chronic liver disease, chronic kidney diseases etc. and rest having a malignant pathology (13.67%) either hematological or solid organ. (Fig-1) About 7% patients had severe thrombocytopenia (platelet count less than 10 000/ cumm). (Fig-2) Conclusions Mean platelet volume and platelet distribution width were significantly higher in non- malignant group . Platelet distribution width in patients with chronic liver disease patients was higher compared to control. Platelet distribution width was also raised in patients of thrombocytopenia in settings of pancytopenia. Fig-1: Distribution of cases based on etiology Fig-2: Proportion of cases with severe thrombocytopenia References Reddy, R. Shridhar, I. M. Khan, and D. M. Phansalkar. "Platelet Distribution Width (PDW) in Thrombocytopenia." Indian Medical Gazette 169174 (2015). Borkataky, Sangeeta, et al. "Role of platelet volume indices in the differential diagnosis of thrombocytopenia: a simple and inexpensive method." Hematology 14.3 (2009): 182-186 Karnad, Anand, and Thomas R. Poskitt. "The automated complete blood cell count: Use of the red blood cell volume distribution width and mean platelet volume in evaluating anemia and thrombocytopenia." Archives of internal medicine 145.7 (1985): 1270-1272 Leader, Avi, David Pereg, and Michael Lishner. "Are platelet volume indices of clinical use? A multidisciplinary review." Annals of medicine 44.8 (2012): 805-816. Elsewefy, D. A., B. A. Farweez, and R. R. Ibrahim. "Platelet indices: consideration in thrombocytopenia." The Egyptian Journal of Haematology39.3 (2014) MPV and PDW were significantly higher in non- malignant group than the control group. (p<0.05) (Table-1) MPV was higher in non malignant group disease group than in patients with malignant etiology. In patients with infection, MPV was more than that of controls in patients with infection. PDW in patients with chronic liver disease patients was higher compared to control. (p<0.05) PDW in pancytopenia was statistically significant as compared to controls. (p<0.05)