Is there a link between mean platelet volume and thrombotic events in antiphospholipid syndrome?

Platelet count and indices as postpartum hemorrhage risk factors: a retrospective cohort study

BACKGROUND

Severe postpartum hemorrhage (SPPH) is the leading cause of maternal mortality and morbidity worldwide. Platelet anomalies frequently occur during pregnancy. However, their role in the etiology of SPPH is largely unknown.

OBJECTIVE

To study the relation between platelet parameters and SPPH.

METHODS

This retrospective single-center cohort included deliveries between 2009 and 2017. SPPH was defined as ≥1000 ml blood loss within 24 h after delivery. Platelet parameters were measured within 72 h before delivery. Multiple imputation was performed for missing data. Odds ratios were adjusted (aORs) for maternal age, multiple gestation, macrosomia, induction of labor, preeclampsia, and hemolysis, elevated liver enzymes, and low platelets syndrome.

RESULTS

A total of 23 205 deliveries were included. Of the 2402 (10.4%) women with thrombocytopenia (<150 × 109 /L), 10.3% developed SPPH, compared with 7.6% of women with a normal platelet count (aOR: 1.34, 95% CI: 1.14-1.59). Women with a platelet count of <50 × 109 /L were most at risk (aOR of 2.24 [1.01-4.94]) compared with the reference group with normal platelet counts; the aOR was 1.22 (0.77-1.93) for the 50-99 × 109 /L platelet count group and 1.31 (1.10-1.56) for the 100-149 × 109 /L platelet count group. Plateletcrit was associated with SPPH (aOR 1.15 [1.08-1.21] per 0.05% decrease), and, although rarely present, a platelet distribution width (PDW) ≥23% (n = 22) also increased the odds of SPPH (aOR 6.05 [2.29-16.20]).

CONCLUSION

Different degrees of thrombocytopenia were independently associated with the occurrence of SPPH. Despite their relation to SPPH, plateletcrit and a PDW of ≥23% have limited additional value in addition to platelet count.

Platelet distribution width is highly associated with thrombotic events in primary antiphospholipid syndrome

OBJECTIVE

Platelet activation is a possible pathogenic process contributing to thromboembolism in antiphospholipid syndrome (APS), and platelet distribution width (PDW) is associated with platelet activation. The objective of this study was to evaluate the association between platelet indices and thrombotic events in patients with primary APS.

METHODS

This single-center cross-sectional study included 207 consecutive patients with APS treated at our institution between 2010 and 2019. Results of blood tests were recorded retrospectively from medical records.

RESULTS

Of the included patients, 135 (65.2%) were female and 72 (34.8%) were male. They were classified into thrombotic (n = 150) or non-thrombotic (n = 57) groups. PDW, mean platelet volume, and large platelet ratio were significantly higher in the thrombotic group. In univariate logistic analysis, PDW was significantly associated with an increased odds of thrombosis [odds ratio (OR) 1.554, 95% confidence interval (CI) 1.289-1.873, p<0.001]. In multivariate logistic analysis, PDW and positive lupus anticoagulant (LA) were risk factors for thrombosis. Receiver operating characteristic analysis showed that PDW, combined with a positive LA, was a reliable indicator of thrombosis, with an area under the curve of 0.796 (95% CI 0.728-0.864). The optimal cutoff value for PDW was 12.4 fl, with a sensitivity of 72.0% and specificity of 77.2%. Multivariate logistic regression of PDW tertiles showed that the odds of thrombosis increased abruptly in the highest tertile.

CONCLUSION

This study confirmed the association between PDW and thrombotic events in APS patients, supporting the theory that platelet activation is a crucial mechanism of thrombosis in APS. Key Points • This study is the first to discuss the correlation between PDW and thromboses in patients with APS. • This study provides evidence of the important role of platelet activation in the pathogenesis of APS.

Thrombosis and thrombocytopenia in antiphospholipid syndrome: their association with mean platelet volume and hematological ratios

OBJECTIVE

To assess the mean platelet volume (MPV), platelet-to-lymphocyte ratio (PLR), the neutrophil-to-lymphocyte ratio (NLR) and the MPV-to-lymphocyte ratio, and to test them according to the clinical/serological status, shift through time and other comorbidities in APS.

METHODS

We included 96 primary APS patients according to the Sydney classification criteria and/or patients with thrombocytopenia and/or autoimmune hemolytic anemia who also fulfilled the serological criteria. We tested aCL, anti-β2GP-I and aPS/PT antibodies and LA. We first registered the MPV and the aforementioned ratios within at least 6 months after an event of thrombosis or thrombocytopenia/AIHA (baseline determination), and during thrombosis/thrombocytopenia/AIHA onset when available (acute event).

RESULTS

A lower baseline MPV and a higher PLR characterized the thrombotic group (n = 74). The AUC for baseline PLR was 0.82 (p < 0.001): SE of 69%, SP 91%, PPV 96%, NPV 74%, LR+ 13.67 and LR- 0.19. During the acute event, both variables increased. The thrombocytopenic group (n = 66) had a higher baseline MPV and a lower PLR, and during an acute event the PLR decreased more deeply. The AUC for MPV was 0.64 (p = 0.02): SE 44%, SP 92%, PPV 86%, NPV 40%, LR+ 3.3 and LR- 0.85. These findings were not related with the aPL antibody profile status, titers or comorbidities.

CONCLUSION

Basal MPV and PLR might help to identify APS patients according to their thrombotic or thrombocytopenic phenotype. These variables change during the acute events and might be the reflex of physiopathological or compensatory mechanisms in APS.

Low Intra-Individual Variation in Mean Platelet Volume Over Time in Systemic Lupus Erythematosus

Platelets have recently emerged as important immune modulators in systemic lupus erythematosus (SLE), in addition to their role in thrombosis and cardiovascular disease. However, studies investigating mean platelet volume (MPV) in SLE are often scarce, conflicting and cross-sectional. In this study, MPV was measured in clinical routine throughout a defined time-period to quantify both individual MPV fluctuations and investigate if such variations are associated with disease activity and clinical phenotypes of SLE. Of our 212 patients, 34 patients had only one MPV value reported with the remaining 178 patients having between 2 and 19 visits with recorded MPV values. The intra-individual MPV variation was low, with a median variation of 0.7 fL. This was further supported by the finding that 84% of patients stayed within their reference interval category (i.e., small, normal or large) over time. In our cohort, no correlation between disease activity and MPV neither cross-sectionally nor longitudinally was found. Mean platelet volume values were significantly smaller in SLE patients (mean 10.5 fL) compared to controls (mean 10.8 fL), p < 0.0001. Based on the reference interval, 2.4% (n = 5) of patients had large-sized platelets, 84.4% (n = 179) had normal-sized and 13.2% (n = 28) had small-sized. A larger proportion (85.7%) of patients with small-sized platelets met the anti-dsDNA criterion (ACR10b; p = 0.003) compared to patients with normal and large (57.6%) sized platelets. In conclusion, the intra-individual MPV variation was of low magnitude and fluctuations in disease activity did not have any significant impact on MPV longitudinally. This lack of variability in MPV over time indicates that measuring MPV at any time-point is sufficient. Further studies are warranted to evaluate MPV as a possible biomarker in SLE, as well as to determine the underlying mechanisms influencing platelet size in SLE.

Mean Platelet Volume and Immature Platelet Fraction in Autoimmune Disorders

Mean platelet volume (MPV), measured using automated blood analysers, has been appraised as a potential biomarker in cardiovascular disease, diabetes mellitus, and cancer. The test, a useful tool in differentiation of thrombocytopenic states, has now been carried out for autoimmune disorders, but data are yet scarce. Controversial results have been obtained in systemic and organ-specific autoimmune disorders. Another test, the immature platelet fraction (IPF) reflects the amount of young, reticulated platelets. IPF is calculated by automated hematology analysis or flow cytometry, and it is usually high in patients with rapid platelet destruction. For both MPV and IPF, standardization of cutoff is a major need. In this review, we focus the current applicability of MPV and IPF as biomarkers in patients with autoimmune diseases.

The effect of standard therapy on mean platelet volume in patients with chronic hepatitis C

Introduction

Chronic hepatitis C (CHC) infection is a systemic disorder that can lead to liver inflammation, fibrosis, cirrhosis, and hepatocellular cancer. The mean platelet volume (MPV) is widely used as an inflammatory marker to evaluate the platelet function and the status of systemic inflammation.

Aim

To determine the pre- and post-treatment MPV values in CHC patients who were administered a 48-week antiviral therapy based on systemic inflammation.

Material and methods

We enrolled 28 patients, diagnosed with CHC genotype 1b, who received a 48-week antiviral therapy and attended regular follow-up, and 28 healthy individuals. In diagnosing CHC, a positive anti-HCV for a minimum duration of 6 months and a positive serum HCV RNA were accepted as the criteria. The patients were assigned to one of two groups based on their group 1 (pre-treatment values) and group 2 (post-treatment values) after 3 months therapy. We analysed and compared the blood samples of all of the groups.

Results

The MPV value was 8.89 ±1.20 in group 1 and 8.00 ±1.07 in group 2, and 8.21 ±1.18 in the control group. The value in group 1 was detected to be statistically significantly different from that in group 2 and the control group (p < 0.0001, p = 0.045, respectively). No statistically significant difference was observed between group 2 and the control group (p = 0.455).

Conclusions

The results of this study suggest that MPV could represent an inexpensive marker for use in assessing low-grade inflammation in patients with CHC.

The relationship between mean platelet volume and thrombosis recurrence in patients diagnosed with antiphospholipid syndrome

Increased mean platelet volume (MPV) is associated with platelet reactivity and is a predictor of cardiovascular risk and unprovoked venous thromboembolism. The aim of our study was to evaluate MPV in patients with confirmed antiphospholipid antibody syndrome (APS) and to identify the correlation between the value of MPV and the recurrence of thrombosis. The studied group consists of 247 patients with a history of thrombosis and/or pregnancy loss (median age 38, range 18–66 years) classified as APS group (n = 70) or APS negative patients (n = 177) according to the updated Sapporo criteria. The control group consisted of 98 healthy subjects. MPV was significantly higher in the group of patients with clinically and laboratory confirmed APS (median 7.85, range 4.73–12.2 fl) in comparison with the controls. It was also higher than in APS negative patients (7.61, range 5.21–12.3 fl). APS patients with triple positivity for antiphospholipid antibodies with respect to Miyakis classification categories had higher MPV values than other APS patients (9.69 ± 1.85 vs. 7.29 ± 1.3 fl, p = 0.001). Recurrent thrombotic episodes were observed in 83 patients, but among the triple positive high-risk patients with APS in 80 % cases (p = 0.0046). In receiver operating characteristic curve analysis, the value of MPV level for thrombosis recurrence prediction in the APS group with sensitivity of 86 % and specificity of 82 % was 7.4 fl. In the multivariate logistic regression model, MPV above 7.4 fl (OR 3.65; 95 % CI 1.38–9.64, p = 0.009) significantly predicts thrombosis recurrence. Our results identify the value of MPV as a prognostic factor of thrombosis recurrence in patients with APS.