Association between lipid profile and platelet indices: the importance of considering the influence of lipid profile while evaluating the clinical utility of platelet indices

The serum lipid profiles in immune thrombocytopenia: Mendelian randomization analysis and a retrospective study

BACKGROUND

Immune thrombocytopenia (ITP) is an autoimmune hemorrhagic disease characterized by increased platelet destruction and impaired thrombopoiesis. The changes in platelet indices depend on the morphology and volume of platelets. Serum lipids have been found to affect platelet formation and activity in certain diseases, thus inducing the corresponding variation of platelet indices.

METHODS

Mendelian randomization (MR) analysis was performed based on databases. The clinical data from 457 ITP patients were retrospectively collected and analyzed, including platelet indices, serum lipids, hemorrhages and therapeutic responses.

RESULTS

MR analysis showed low high-density-lipoprotein-cholesterol (HDL-C), low apolipoprotein A-1, high triglyceride (TG) and high apolipoprotein B (ApoB) caused high platelet distribution width (PDW); high low-density-lipoprotein-cholesterol (LDL-C) increased mean platelet volume (MPV). In ITP, there were positive correlations between platelet count with TG, PDW with HDL-C and ApoB, and plateletcrit with TG and non-esterified fatty acid, and the correlation had gender differences. Bleeding scores were negatively correlated with cholesterol and LDL-C. LDL-C and homocysteine were risk factors for therapeutic responses.

CONCLUSIONS

Serum lipids, especially cholesterol were tightly correlated with platelet indices, hemorrhage and therapeutic effects in ITP patients. These results provide clinical references for the management of serum lipids, and highlight the necessity to further explore the relationship between lipids and pathogenesis of ITP.

TRIAL REGISTRATION

No: NCT05095896, October 14, 2021, retrospectively registered.

Mean Platelet Volume, Red Cell Distribution Width, and Complete Blood Cell Count Indices in Retinal Vein Occlusions

PURPOSE

To evaluate the role of some complete blood cell count (CBC)-derived measures in retinal vein occlusion (RVO).

METHODS

This was a retrospective case-control study, including 127 newly diagnosed RVO patients and 127 sex- and age-matched subjects without RVO. A blood sample was obtained and a complete blood cell count was performed. Neutrophil/lymphocyte ratio (NLR), derived NLR [dNLR = neutrophils/(white blood cells‒neutrophils)], and platelet/lymphocyte ratio (PLR) were calculated. We also performed a meta-analysis of the available data, ours included, on the correlation between mean platelet volume (MPV) and RVO. Standardized mean differences (SMD) were used to build forest plots and assess differences in MPV values between RVO patients and controls.

RESULTS

Median MPV and red cell distribution width (RDW) were 8.7 fL (IQR = 7.8-9.5) and 13.2% (IQR = 12.4-14.2) in RVO patients and 7.8 fL (IQR = 7.1-8.5) and 13% (IQR = 12-14) in controls. RVO patients had significantly higher values of MPV (P < .0001) and RDW (P = .005). There were no significant differences between the values of white blood cells, lymphocytes, neutrophils, platelets, NLR, dNLR, and PLR. Multivariable logistic regression analysis revealed a statistically significant correlation between increased MPV and RVO (OR = 1.74, 95% CI = 1.38-2.2, P < .0001). 519 RVO patients and 414 controls from 6 case-control studies were included in the meta-analysis. Pooled results disclosed that MPV values were significantly higher in RVO patients (SMD = 0.41 fL, 95% CI = 0.04-0.79, P = .032), but extreme heterogeneity was observed (I² = 86.1%, P < .001).

CONCLUSION

Results suggest lack of association between CBC-derived inflammatory indices and RVO. Conversely, MPV and, to a lesser extent, RDW may be disease biomarkers in RVO.

Altered Platelet Fatty Acids in Dengue Cases by Gas Chromatography-Mass Spectrometry Analysis

BACKGROUND

The role of dengue virus in altering the functional properties of platelets remains poorly understood. Few studies have observed that changes in fatty acids are found to have an effect on platelet activation and aggregation. Also, platelet fatty acids have not been extensively studied in dengue so far. So, we aimed to study the fatty acids of platelet membranes in patients with dengue.

METHODS

Gas chromatography-mass spectrometry (GC-MS) method was used to analyze fatty acids in the lipid extracts of platelets isolated from the study participants.

RESULTS

GC-MS analysis of platelet lipids identified and quantified nearly 23 unique lipid molecules on platelet membrane. We observed significant alterations with some of the fatty acids in patients with dengue compared to controls. Within dengue cases, increase in unsaturated fatty acids in severe dengue was observed compared to non-severe dengue. From baseline to defervescence, no difference in fatty acids was observed in dengue platelets. This indicates that in dengue, platelet physiology remains altered even after the febrile phase.

CONCLUSION

To the best of our knowledge, this is the first study characterizing the differential expression of platelet fatty acids in dengue infection. However, further studies are warranted to expound the underlying cause for thrombocytopenia and platelet dysfunction in dengue.