Duration of the diabetic state altered platelet indices from baseline values in a streptozotocin-induced rat model for type 1 diabetes mellitus.

BACKGROUND: Changes in platelet indices in naturally occurring type I diabetes mellitus (T1DM) have been described in several studies. In this study, platelet indices such as platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), and MPV to PLT ratio were investigated according to diabetic duration after streptozotocin (STZ)-induced T1DM, as well as for their correlation with glucose. METHODS: Forty healthy adult Wistar rats were randomly assigned to four experimental groups of ten (5 rats of each sex), including the control group, the 7, 14, and 28 days diabetic groups (D7, D14, and D28, respectively). RESULTS: In diabetic groups, plasma glucose was significantly higher than in control (P < 0.01). D7, D14, and D28 groups presented significantly lower PLT than the control (P < 0. 01). A significant decrease in PCT was observed in D14 and D28 females (P < 0.05). Mean platelet volume was significantly higher in the D28 group than in to control. D28 females also showed a significant difference in PLT, MPV, and the MPV-to-PLT ratio compared with D7 females (P < 0.05). A comparison between D28 females and males showed a significant difference in PDW (P < 0.05). Both females and males showed a significant correlation between glucose and PLT, PCT, MPV, and the MPV-to-PLT ratio. CONCLUSIONS: Platelet indices change significantly with the duration of diabetes compared with the baseline values, and female and male rats did not have significant differences in platelet indices in any period except the 28 days.

Association of platelet indices with glycemic status in diabetic dogs.

We investigated the platelet count (PLT), mean platelet volume (MPV), and plateletcrit (PCT) in dogs with type 1 diabetes mellitus (DM) compared to healthy controls, and their association with the major fraction of glycated hemoglobin (HbA1c). Blood samples from 33 clinically healthy dogs and 14 newly diagnosed diabetic dogs were included. CBCs were performed with the Advia 120; HbA1c was determined using a validated assay (Capillarys 2 flex-piercing; Sebia). Median [range] PLT and PCT were significantly higher (p = 0.040 and p = 0.010, respectively) in diabetic dogs (434 [176-987] × 109/L and 0.60 [0.26-1.22]%, respectively) compared to healthy dogs (297 [223-671] × 109/L and 0.35 [0.24-0.87]%, respectively]. Thrombocytosis was observed in 6 of 14 (43%) diabetic dogs. The median MPV was not significantly different (p = 0.114) between the diabetic (13.6 fL, 10.1-22.6 fL) and healthy dogs (11.9 fL, 8.6-19.1 fL). A significant, albeit weak, correlation was detected between HbA1c and PLT (rho = 0.298, p = 0.042) and PCT (rho = 0.340, p = 0.019), but no significant correlation was found with MPV (rho = 0.199, p = 0.180). Canine DM was associated with increased PLT and PCT, which was correlated with glycemic status. Our findings suggest dysregulated megakaryopoiesis in diabetic dogs, but this should be confirmed by large-scale studies, and the clinical implications should be investigated.

Investigation of platelet measurands in dogs with hematologic neoplasia.

INTRODUCTION: Thrombocytopenia has been associated with some neoplastic processes, including hematologic neoplasia. There is no information regarding specific changes in platelet measurands in dogs with hematologic neoplasia compared with healthy dogs. The objectives of our study were to establish RIs, evaluate platelet measurands in dogs with hematologic neoplasia, and compare these measurands in patients with hematologic malignancies with or without thrombocytopenia. METHODS: This was a retrospective study. Platelet measurands were determined using the ADVIA 120 Hematology analyzer when a CBC was performed and included the platelet count, MPV, platelet distribution width (PDW), plateletcrit (PCT), mean platelet component (MPC), platelet component distribution width (PCDW), mean platelet mass (MPM), platelet mass distribution width (PMDW), and number of large platelets. Reference intervals were determined retrospectively using data from 129 healthy dogs. Patients with hematologic neoplasia (n = 50) were identified through retrospective evaluation of medical records from the Auburn University Veterinary Teaching Hospital and separated into thrombocytopenic (n = 20) and nonthrombocytopenic groups (n = 30). RESULTS: Platelet count and PCT were significantly higher in older healthy dogs compared with younger dogs. Significant differences were identified when comparing healthy dogs with those with hematologic neoplasia without thrombocytopenia for PDW, PCDW, PMDW, and the number of large platelets, indicating the presence of more heterogeneous platelets. Thrombocytopenic dogs with hematologic neoplasia had significantly decreased MPCs and increased MPVs, MPMs, and PCDWs compared with nonthrombocytopenic dogs with neoplasia. CONCLUSIONS: Dogs with hematologic neoplasia had more heterogeneous platelets, whereas thrombocytopenic patients with neoplasia had more activated platelets.

Platelet volume and plateletcrit in dogs with presumed primary immune-mediated thrombocytopenia.

BACKGROUND: Mean platelet volume (MPV) and plateletcrit (PCT) are indices used in evaluating immune-mediated thrombocytopenia (IMT) in humans and in dogs with congenital macrothrombocytopenia. These indices may provide clinically valuable information in acquired thrombocytopenia. HYPOTHESIS/OBJECTIVES: Dogs with presumed primary IMT will have increased MPV, and therefore platelet mass (PCT) will increase faster than platelet count (PLT) during recovery. ANIMALS: Forty-nine dogs with automated PLT < 30,000/µL because of presumed primary IMT and hematocrit (HCT), PCT, MPV, and platelet distribution width determined from the same complete blood count (CBC), and 46 healthy controls. METHODS: Case-control retrospective study; PLT, PCT, MPV, and platelet distribution width (PDW) were recorded from CBCs from 49 dogs, with 45 having data collected on the day of presentation. Fifteen were confirmed to have attained a PLT ≥ 75,000/µL on at least 1 CBC within 15 days after admission. The PCT equivalent to a PLT of 75,000/µL (assuming an average MPV) was calculated for comparison with PLT in terms of time to achieve a threshold of platelet mass by the 2 measures. RESULTS: Mean platelet volume was higher in IMT dogs (17.3 fl) than the reference population (10.5 fl) (P < .0001). The PDW was not significantly different among the groups. The median time for PCT to reach threshold in confirmed responders was faster (3 days) compared with PLT (4 days). CONCLUSIONS AND CLINICAL IMPORTANCE: Immune-mediated thrombocytopenia is characterized by increased MPV. Time to achieve a threshold PCT tended to be shorter than PLT, suggesting that PCT may be a useful platelet parameter for monitoring dogs with IMT.

Platelet count and plateletcrit in Cavalier King Charles Spaniels and Greyhounds using the Advia 120 and 2120.

BACKGROUND: Models for the regulation of thrombopoiesis predict that platelet mass is the biologically regulated variable, yet clinical evaluations of thrombopoiesis are often based on platelet number. When thrombocytopenia and variation in platelet size occur concurrently, platelet count may poorly estimate total platelet mass, confounding clinical decision making. OBJECTIVE: We hypothesized that plateletcrit (PCT) provides clinically important information when platelet number is an incomplete representation of platelet mass, such as in genetic macrothrombocytopenia. METHODS: We retrospectively compared platelet count and PCTs with general reference intervals for 4 groups of dogs: sick Cavalier King Charles Spaniels (CKCS) and Greyhounds, presented for nonhematopoietic disease to the University of Minnesota (measured using an Advia 2120) and Auburn University Teaching Hospitals (measured using an Advia 120) over a 3-year period. RESULTS: A canine PCT reference interval of 0.129-0.403% was established. None of the 4 sample groups had significantly more individuals below the reference interval for plateletcrit. For platelet count, only the 2 CKCS groups had significantly more individuals below the reference interval than predicted. CONCLUSION: Use of the PCT as determined by the Advia 120/2120 appeared to avoid overestimation of low platelet mass in sick CKCS in a clinical setting. In contrast, the PCT performed similarly to the platelet count in evaluation of platelet mass in sick Greyhounds. Evaluation of the PCT should be considered in other conditions associated with increased mean platelet volume.