Lack of association between mean platelet volume and disease activity in systemic lupus erythematosus patients: a systematic review and meta-analysis

Mean Platelet Volume Is Related to Cumulative Disease Damage in Patients with Systemic Lupus Erythematosus

Mean platelet volume (MPV), which represents the average platelet size in femtoliters, has emerged as a reliable biomarker in several systemic and chronic disorders. However, its relationship with disease characteristics in large series of patients with systemic lupus erythematosus (SLE) has not been exhaustively studied to date. In the present work, we aimed to analyze how disease characteristics, including disease activity and cumulative damage, relate to MPV in a well-characterized series of SLE patients. In total, 179 patients with SLE and 181 age- and sex-matched healthy controls were recruited. Complete blood counts including MPV were assessed. Linear multivariable analysis was performed to evaluate the relationship between MPV and SLE disease characteristics, including composite scores of disease activity and damage. MPV was significantly lower in patients with SLE compared to controls after multivariable analysis (beta coefficient, -0.7 [95% confidence interval, -1.1 to -0.3)] fL, p < 0.001). Although the SLEDAI disease activity index was not related to MPV, the SLICC score measuring cumulative disease damage was significantly associated with lower MPV values after adjustment for covariates. Elements of the SLICC score that were associated with lower MPV levels were those pertaining to the kidney, peripheral vascular, and musculoskeletal manifestations of the disease. In conclusion, MPV is lower in patients with SLE compared to matched controls. This MPV downregulation is primarily due to the renal, peripheral vascular and musculoskeletal manifestations of the disease. MPV may represent a biomarker of accrual disease damage in SLE.

Ortalama trombosit hacmi ve ortalama trombosit hacmi/trombosit sayısı oranının periton diyalizi başlandıktan bir yıl sonraki değişimi

Aim: Cardiovascular diseases are the most common cause of mortality in patients undergoing peritoneal dialysis. Thrombocyte indices which are indicators of platelet activation are predictors of cardiovascular events. We aim to examine the change in platelet count, mean platelet volume, and mean platelet volume to platelet count ratio one year after initiation of peritoneal dialysis in patients with end-stage renal disease. Materials and Methods: This retrospective study included 28 patients. Demographic and clinical characteristics of the patients at the time of initiation of peritoneal dialysis were recorded from the patient files. Laboratory data within the last month before the initiation of peritoneal dialysis and in the first year were recorded from the patient files. The mean platelet volume to platelet count ratio was calculated as mean platelet volume (femtolitres) divided by platelet count (number of thousand platelets/microliter). Results: The mean age was 51.1 ± 14.6 years, and 42.8% of the patients were male. Diabetic nephropathy and hypertensive nephropathy were the most common causes of end-stage renal disease. One year after the initiation of peritoneal dialysis, the urea level decreased significantly, and C-reactive protein level increased significantly. Platelet count increased from 240 ± 55 x10 3 /μL to 274 ± 53 x10 3 /μL (p=0.003) and mean platelet volume decreased from 10.7 ± 1.0 fl to 10.2 ± 0.8 fl (p

Mean Platelet Volume Significantly Decreases in the Remission Period of Systemic Lupus Erythematosus Patients with Renal Involvement

Systemic lupus erythematosus (SLE) is a disease of the immune system with an unknown etiology. It is a unique disease that has a wide range of clinical and laboratory findings according to the organ or system involved and the activity of the disease. Mean platelet volume (MPV) is a simple parameter of the blood and is widely and easily available. It has been evaluated as a sign of inflammation in many kinds of diseases recently. In this study, we retrospectively analyzed the laboratory parameters and clinical features of 36 SLE patients with renal involvement and nephrotic-range proteinuria in the active and remission periods of the disease between 2005 and 2013. We found that the mean MPV in the active disease of the period was statistically significantly higher than in the remission period (8.30 ± 1.09 and 7.88 ± 0.7, respectively, P = 0.007).

Enrichment of complement, immunoglobulins and autoantibody targets in the proteome of platelets from patients with Systemic Lupus Erythematosus (SLE)

Background  Systemic lupus erythematosus (SLE) is a complex disease characterized by autoimmunity toward apoptotic cells, excessive amounts of circulating immune complexes, and complement activation. A decreased platelet size has been observed in SLE and their nonhemostatic functions may play an active role in the disease. The main objective of this study was to find clues that could explain their decreased size and functional role, analyzing the entire platelet proteome.

Methods  Platelets were isolated from 23 patients with SLE. The five individuals with the highest and lowest average platelet forward scatter were selected for further analysis. Platelet protein content was analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS) and compared with platelets from five healthy controls. Data are available via ProteomeXchange with identifier PXD031202.

Results  Out of 2,572 proteins identified, 396 had significantly different levels (ANOVA q -value ≤ 0.01). Forty proteins, including immunoglobulin-, complement- and phosphatidylserine-binding proteins had higher abundance in platelets from SLE patients, largely independent of size (fold difference of ≥1.5 and a t -test p -value of ≤0.05 as cut-off). Functional characterization revealed increased degranulation and skewed hemostatic balance in platelets from SLE patients. In the SLE proteome, immunoglobulin proteins were negatively correlated to serum complement C3 and C4 and the highest relative levels were detected in platelets of normal size.

Conclusion  Platelets from SLE patients shared a specific protein profile, including immunoglobulins, complement proteins, and autoantigens, largely independent of the platelet size and in agreement with an integrated role for platelets in SLE.

Comparison of mean platelet volume (MPV) and red blood cell distribution width (RDW) between psoriasis patients and controls: A systematic review and meta-analysis

BACKGROUND

The predictive role of hematological indexes of mean platelet volume (MPV) and red cell distribution width (RDW) has been demonstrated in cardiovascular disease concomitant with psoriasis. This meta-analysis is intended to assess whether MPV and RDW can also serve as biomarkers for the early diagnosis and disease severity assessment of psoriasis.

MATERIAL AND METHODS

13 studies which enrolled 1331 psoriasis patients and 919 healthy volunteers were included after screening the search results from PubMed, Embase and the Cochrane Library since inception to Mar 14, 2020. MPV of psoriasis participants and their counterparts was assessed in 10 studies, and RDW was evaluated in 4 studies, while the disease severity was measured by the Psoriasis Area and Severity Index (PASI) in 11 studies. Random-effect model analysis was applied to calculate pooled standard mean difference (SMD) with 95% confidence interval (95% CI).

RESULTS

Associations of MPV and RDW with the presence of psoriasis were demonstrated (MPV: SMD = 0.503, 95% CI: 0.242-0.765; RDW: SMD = 0.522, 95% CI: 0.228-0.817), but no statistically significant correlation of MPV and disease severity of psoriasis was found in meta-regression analysis (p = 0.208). Subgroup analysis revealed that the diagnosis value of MPV and RDW was consistent regardless of PASI and study type. Heterogeneity analysis between studies was implemented by chi-squared test and I2 statistics. Begg's and Egger's test were utilized for the evaluation of publication bias. The sensitivity analysis revealed no significant alteration no matter which study was excluded.

CONCLUSION

MPV and RDW could serve as promising predictive diagnostic biomarkers of psoriasis.

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.

Platelet indices in patients with chronic inflammatory arthritis: a systematic review and meta-analysis

Correlation between platelet indices and chronic inflammatory arthritis (CIA) remains a moot point today. This meta-analysis aimed to evaluate whether platelet (PLT) count, mean platelet volume (MPV) and platelet distribution width (PDW) associated with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA). A systematic literature search was performed in PubMed, EMBASE, and Web of Science up to August 2019. Pooled standardized mean differences (SMD) and 95% confidence interval (CI) were calculated using a random-effect model. As a result, 34 studies were included, encompassing 17 on RA, 12 on AS, 3 on PsA and 2 on both RA and AS. In these studies, PLT count was significantly higher in RA (SMD = 0.55, 95% CI = 0.36-0.73, P < .001), AS (SMD = 0.53, 95% CI = 0.36-0.70, P < .001) and PsA patients (SMD = 1.29, 95% CI = 0.82-1.77, P < .001) than that in healthy subjects, while MPV and PDW presented nonsignificant differences in these intergroup comparisons (P > .05), and similar results were observed in subgroup analyses. The meta-regression analysis demonstrated that there were strong positive correlations between erythrocyte sedimentation rate and PLT count, and weak correlation trend between the disease activity score and PLT count in both RA and AS subjects without statistically significant difference. The sensitivity analysis indicated that these results were not unduly influenced by any single study. In conclusion, this meta-analysis demonstrated that PLT count was elevated in CIA patients and could be suitable for evaluating the disease activity, whereas MPV and PDW were independent of CIA.

Large and small platelets-(When) do they differ?

Platelets are most important in providing cellular hemostasis but also take part in inflammation and immune processes. Increased platelet size has been regarded as a feature describing a young and more reactive subpopulation until studies were published which questioned this concept. Moreover, changes of platelet size given by the mean platelet volume (MPV) were described for immune thrombocytopenia, cardiovascular disease, atherosclerosis, venous thromboembolism, chronic lung disease, sepsis, cancer-associated thrombosis, autoimmune disorders, and others. This review summarizes the literature on what is known about platelets with different size and describes controversies of studies with large and small platelets putting a focus on their thrombogenicity, age, and on the association of MPV with the mentioned diseases.

Neutrophil/lymphocyte ratio, monocyte/lymphocyte ratio, and mean platelet volume as systemic inflammatory markers in different states of bipolar disorder

Background: Currently, increasing evidence supports the hypothesis that alterations in the immune-inflammatory system are critical for the pathophysiology of bipolar disorder (BD). Neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), and mean platelet volume (MPV) have recently been investigated as inexpensive and simple inflammatory markers. Aims: The aim of this study is to compare NLR, PLR, MLR, and MPV in depressive, manic, and euthymic patients with BD and healthy controls, and to evaluate whether values of NLR, PLR, MLR, and MPV are possible state or trait biomarkers in BD. Methods: This retrospective study was conducted with 341 patients with BD (100 patients in a depressive state, 141 patients in a manic state, and 100 patients in a euthymic state) and 114 healthy controls. Results: We found that patients with BD in manic states had higher levels of MPV, NLR, and MLR, and patients with BD in depressive states had higher levels of MPV than the controls. Moreover, MPV predicted all states of BD, while NLR and MLR predicted the manic state of BD. Conclusions: NLR, MLR, and MPV obtained from simple and inexpensive blood tests were significantly higher in patients with BD than in healthy controls, which each imply low-grade inflammation. MPV may serve as a possible trait biomarker of BD, while NLR and MLR may both serve as possible state biomarkers of the manic state.

Platelets in Skin Autoimmune Diseases

Systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and small vessel vasculitis are three autoimmune diseases frequently manifested in the skin. They share common pathogenic features, including production of autoantibodies, loss of tolerance to self-antigens, tissue necrosis and fibrosis, vasculopathy and activation of the coagulation system. Platelets occupy a central part within the coagulation cascade and are well-recognized for their hemostatic role. However, recent cumulative evidence implicates their additional and multifaceted immunoregulatory functions. Platelets express immune receptors and they store growth factors, cytokines, and chemokines in their granules enabling a significant contribution to inflammation. A plethora of activating triggers such as damage associated molecular patterns (DAMPs) released from damaged endothelial cells, immune complexes, or complement effector molecules can mediate platelet activation. Activated platelets further foster an inflammatory environment and the crosstalk with the endothelium and leukocytes by the release of immunoactive molecules and microparticles. Further insight into the pathogenic implications of platelet activation will pave the way for new therapeutic strategies targeting autoimmune diseases. In this review, we discuss the inflammatory functions of platelets and their mechanistic contribution to the pathophysiology of SSc, ANCA associated small vessel vasculitis and other autoimmune diseases affecting the skin.