Rheohaemapheresis of ophthalmological diseases and diseases of the microcirculation

The Impact of Convertase Subtilisin/Kexin Type 9 Monoclonal Antibodies with and without Apheresis on Platelet Aggregation in Familial Hypercholesterolemia

BACKGROUND AND AIMS

It is well known that elevated cholesterol is associated with enhanced platelet aggregation and patients suffering from familial hypercholesterolemia (FH) have a high risk of thrombotic cardiovascular events. Although decreasing cholesterol level is associated with attenuation of platelet hyperactivity, there are currently no data on the effect of convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9ab) on platelet reactivity in FH. The aim of the study was to analyse the impact of different therapies including PCSK9ab on platelet aggregation in FH.

METHODS

This study enrolled all 15 patients treated in the University Hospital Hradec Králové for FH. PCSK9ab have been administered in 12 of 15 patients while 8 patients were also undergoing lipid apheresis. Blood samples from all patients including pre- and post-apheresis period were tested for platelet aggregation triggered by 7 inducers, and the effect of 3 clinically used drugs (acetylsalicylic acid, ticagrelor and vorapaxar) was compared as well.

RESULTS

Although apheresis decreased the reactivity of platelets in general, platelet responses were not different between non-apheresis patients treated with PCSK9ab and apheresis patients (post-apheresis values) with the exception of ristocetin. However, when compared to age-matched healthy population, FH patients had significantly lower platelet aggregation responses to 4 out of 7 used inducers and higher profit from 2 out of 3 used antiplatelet drugs even after exclusion of FH patients regularly receiving conventional antiplatelet treatment.

CONCLUSION

This study showed for the first time the suitability of PCSK9ab treatment for reduction of platelet reactivity in FH patients.

Long-Term LDL-Apheresis Treatment and Dynamics of Circulating miRNAs in Patients with Severe Familial Hypercholesterolemia

Lipoprotein apheresis (LA) is a therapeutic option for patients with severe hypercholesterolemia who have persistently elevated LDL-C levels despite attempts at drug therapy. MicroRNAs (miRNAs), important posttranscriptional gene regulators, are involved in the pathogenesis of atherosclerosis. Our study aimed to monitor the dynamics of twenty preselected circulating miRNAs in patients under long-term apheresis treatment. Plasma samples from 12 FH patients (men = 50%, age = 55.3 ± 12.2 years; mean LA overall treatment time = 13.1 ± 7.8 years) were collected before each apheresis therapy every sixth month over the course of four years of treatment. Eight complete follow-up (FU) samples were measured in each patient. Dynamic changes in the relative quantity of 6 miRNAs (miR-92a, miR-21, miR-126, miR-122, miR-26a, and miR-185; all p < 0.04) during FU were identified. Overall apheresis treatment time influenced circulating miR-146a levels (p < 0.04). In LDLR mutation homozygotes (N = 5), compared to heterozygotes (N = 7), we found higher plasma levels of miR-181, miR-126, miR-155, and miR-92a (all p < 0.03). Treatment with PCSK9 inhibitors (N = 6) affected the plasma levels of 7 miRNAs (miR-126, miR-122, miR-26a, miR-155, miR-125a, miR-92a, and miR-27a; all p < 0.04). Long-term monitoring has shown that LA in patients with severe familial hypercholesterolemia influences plasma circulating miRNAs involved in endothelial dysfunction, cholesterol homeostasis, inflammation, and plaque development. The longer the treatment using LA, the better the miRNA milieu depicting the potential cardiovascular risk.

The Effect of 4-Methylcatechol on Platelets in Familial Hypercholesterolemic Patients Treated with Lipid Apheresis and/or Proprotein Convertase Subtilisin Kexin 9 Monoclonal Antibodies

Elevated low-density lipoprotein (LDL) cholesterol levels lead to atherosclerosis and platelet hyperaggregability, both of which are known culprits of arterial thrombosis. Normalization of LDL cholesterol in familial hypercholesterolemia (FH) is not an easy task and frequently requires specific treatment, such as regularly performed lipid apheresis and/or novel drugs such as proprotein convertase subtilisin kexin 9 monoclonal antibodies (PCSK9Ab). Moreover, a high resistance rate to the first-line antiplatelet drug acetylsalicylic acid (ASA) stimulated research of novel antiplatelet drugs. 4-methylcatechol (4-MC), a known metabolite of several dietary flavonoids, may be a suitable candidate. The aim of this study was to analyse the antiplatelet effect of 4-MC in FH patients and to compare its impact on two FH treatment modalities via whole-blood impedance aggregometry. When compared to age-matched, generally healthy controls, the antiplatelet effect of 4-MC against collagen-induced aggregation was higher in FH patients. Apheresis itself improved the effect of 4-MC on platelet aggregation and blood from patients treated with this procedure and pretreated with 4-MC had lower platelet aggregability when compared to those solely treated with PCKS9Ab. Although this study had some inherent limitations, e.g., a low number of patients and possible impact of administered drugs, it confirmed the suitability of 4-MC as a promising antiplatelet agent and also demonstrated the effect of 4-MC in patients with a genetic metabolic disease for the first time.

Multiplex Protein Biomarker Profiling in Patients with Familial Hypercholesterolemia

Familial hypercholesterolemia (FH), is an autosomal dominant disorder caused by mutations in the LDLR, APOB, PCSK9, and APOE genes and is characterized by high plasma levels of total and low-density lipoprotein (LDL) cholesterol. Our study aimed to analyze the influences of two different therapies on a wide spectrum of plasma protein biomarkers of cardiovascular diseases. Plasma from FH patients under hypolipidemic therapy (N = 18; men = 8, age 55.4 ± 13.1 years) and patients under combined long-term LDL apheresis/hypolipidemic therapy (N = 14; men = 7; age 58.0 ± 13.6 years) were analyzed in our study. We measured a profile of 184 cardiovascular disease (CVD) associated proteins using a proximity extension assay (PEA). Hypolipidemic therapy significantly (all p < 0.01) influenced 10 plasma proteins (TM, DKK1, CCL3, CD4, PDGF subunit B, AGRP, IL18, THPO, and LOX1 decreased; ST2 increased). Under combined apheresis/hypolipidemic treatment, 18 plasma proteins (LDLR, PCSK9, MMP-3, GDF2, CTRC, SORT1, VEGFD, IL27, CCL24, and KIM1 decreased; OPN, COL1A1, KLK6, IL4RA, PLC, TNFR1, GLO1, and PTX3 increased) were significantly affected (all p < 0.006). Hypolipidemic treatment mainly affected biomarkers involved in vascular endothelial maintenance. Combined therapy influenced proteins that participate in cholesterol metabolism and inflammation.

Changes of the complement system and rheological indicators after therapy with rheohemapheresis

INTRODUCTION

In the last 10 years, many studies have been published on the role of the complement system in microcirculation disorders. However, as for the changes of complement components after rheohemapheresis, there is still a lack of detailed data in the literature. Complement changes may play an important role in pathogenesis of some microcirculation disorders, such as age-related macular degeneration and acute hearing loss. The objective of this study was to investigate the effect of rheohemapheresis on the basic complement pathways.

PATIENTS AND METHODS

32 patients were treated with rheohemapheresis, including 16 patients (10 men and 6 women) for age-related macular degeneration (AMD), mean age 69.7 ± 6.06 years (range 62-87 years) and 16 patients (11 men and 5 women) aged 56.4 ± 11.5 (range 34-73 years) for acute hearing loss.

RESULTS

Rheohemapheresis led to a significant drop of all three complement-activation pathways in both groups of patients. Moreover, complement factor H was also reduced.

CONCLUSION

The observed reduction in all three basic complement activation pathways after rheohemapheresis could be clinically important. The search continues both to find substances which influence complement systems and to develop more effective new drugs that require less frequent administration and that provide improved intraocular therapy for AMD patients.

Blood levels of antioxidants during age-related macular degeneration treatment by rheohaemapheresis

AIMS

Rheohaemapheresis treatment influences rheological markers and most likely improves metabolism in affected retinal areas, resulting not only in absorption of soft drusen but also reduction or complete disappearance of drusenoid retinal pigment epithelium detachments. However, the character of the treatment process has raised suspicion that there is a decrease not only in cholesterol but also in antioxidants, such as vitamin E and vitamin A.

METHODS

Twenty-three patients with the progressive dry form of age-related macular degeneration were each treated with 8 procedures of rheohaemapheresis. We measured levels of vitamin E (α-tocopherol), the vitamin E/cholesterol ratio in serum and lipoproteins (VLDL, LDL, HDL). Vitamin E in erythrocyte membrane and serum vitamin A (retinol) were also measured. These parameters were determined before and after rheohaemapheresis. Erythrocyte superoxide dismutase, erythrocyte glutathione peroxidase and serum malondialdehyde were analysed as markers of antioxidant activity and lipid peroxidation, respectively.

RESULTS

In serum, the VLDL and LDL fraction ratios of vitamin E/cholesterol increased significantly. Additionally, the HDL fraction ratio showed an increase but this was not statistically significant. The patients showed no clinical signs of vitamin E deficiency, and their serum concentrations of vitamin E did not differ from normal values. The results show that rheohaemapheresis in addition to causing a significant reduction in atherogenic LDL cholesterol, may have favourable additive anti-atherogenic effects due to a relative increase in the content of vitamin E in the lipoprotein fractions.

Dynamics of blood count after rheohemapheresis in age-related macular degeneration: possible association with clinical changes

Background. Rheohemapheresis (RHF) is a method that can stop the activity of the dry form of age-related macular degeneration (AMD). The pathophysiologic mechanisms are not well understood, and the effects of the RHF procedures extend beyond the time of the individual procedures. Patients and Methods. We present the data for 46 patients with AMD treated with a series of 8 rheohemapheretic procedures. Blood count parameters were measured before the first and the last procedures. The clinical effect was judged by changes in the drusenoid pigment epithelium detachment (DPED) area before and after the rheopheretic sessions. Results. Rheopheresis caused a decrease in hemoglobin (P < 0.001), a decrease in leukocytes (P < 0.034), and an increase in platelets (P < 0.005). We found a negative correlation between the amount of platelets and their volume (P < 0.001, Pearson correlation coefficient: −0.509). We identified the platelet/MPV ratio as a good predictor of the clinical outcome. Patients with a platelet/MPV ratio greater than 21.5 (before the last rheopheresis) had a significantly better outcome (P = 0.003, sensitivity of 76.9% and specificity of 80%). Conclusion. Several basic blood count parameters after RHF can be concluded to significantly change, with some of those changes correlating with the clinical results (reduction of the DPED area).

Long-term outcomes of rheohaemapheresis in the treatment of dry form of age-related macular degeneration

Purpose. Determining long-term effects of rheohaemapheresis on the dry form of age-related macular degeneration. Methods. This study evaluates 19 patients, average age of 67.6 years, treated with rheohaemapheresis and 18 patients, average age of 72.8 years, comprising the control group. Minimum follow up period was 3.5 years. Each treated patient received a series of 8 sessions of rheohaemapheresis of 1.5 plasma volumes within 10 weeks. We measured the drusenoid pigment epithelium detachment (DPED), best-corrected visual acuity (BCVA), electroretinography (ERG), and rheological parameters. Results. In the treatment group, the baseline BCVA was 0.74 (0.36-1.0) 95% CI and BCVA after 3.5 years was 0.79 (0.41-1.0) 95% CI (P = 0.726). In the control group, the baseline BCVA was 0.71 (0.15-1.0) 95% CI and BCVA after 3.5 years decreased to 0.7 (0.32-0.87) 95% CI (P = 0.031). Baseline DPED was 6.78 ± 3.79 mm(2); after 3.5 years, it decreased to 4.13 ± 3.84 mm(2) (P < 0.001). In the control group, the baseline DPED was 4.09 ± 3.48 mm(2); after 3.5 years, it increased to 6.69 ± 4.2 mm(2) (P = 0.001). We noted increasing levels of positive wave peaking at 50 milliseconds (P50) after treatment (P = 0.022) and a stable amplitude of photopic responses of treated patients. Conclusion. Over the long term, rheohaemapheresis reduced the DPED, improved the function of photoreceptors, and prevented the decline of BCVA.

Anti-TNFα therapy early improves hemodynamics in local intestinal and extraintestinal circulations in active Crohn's disease

BACKGROUND AND AIMS

Active Crohn's disease affects intestine but may alter other locations as eyes vasculature. Previous studies provide evidence of elevated blood flow velocities (BFv) and volume (BFV) in superior mesenteric artery (SMA). We prospectively studied hemodynamics in feeding arteries of bowel and eyes before and 2 weeks after treatment induction with anti-TNFα.

METHODS

Fifteen patients (5 females, 10 males, 35.4 ± 9.0 years, mean ± SD) with active Crohn's disease for 7.5 ± 7.7 years were enrolled. Ultrasound imaging was performed before and 2 weeks after treatment in SMA and retrobulbar arteries: central retinal (CRA), temporal posterior ciliary (TPCA) and ophthalmic (OA) arteries. Serum markers of inflammation (CRP and fibrinogen), arterial blood pressures (ABP) and skin flow-mediated dilation (sFMD) were measured and patients were compared to 10 control age- and sex-matched subjects.

RESULTS

Before treatment, CRP and fibrinogen plasma concentrations, SMA BFV (339 ± 100 mL/min) were higher in patients than in controls by 8.5-fold (p<0.001), 1.4-fold (p<0.01) and 1.5-fold, respectively (p<0.01). BFv in CRA (3.5 ± 0.7 cm/s) and TPCA (4.4 ± 1.0 cm/s), sFMD (371 ± 469%) were significantly lower than in controls by 83%, 73% and 52% respectively (p<0.05). Two weeks after treatment, CRP and fibrinogen decreased, SMA BFV was normalized (230 ± 39L/min, p<0.01), BFv in CRA, TPCA and OA increased respectively to 4.0 ± 1.1 (p<0.05), 5.2 ± 1.4 (p<0.001), 8.9 ± 3 cm/s (p<0.05). ABP and sFMD remained unchanged.

CONCLUSIONS

In active Crohn's disease, a first anti-TNFα administration rapidly normalized concomitantly plasma inflammatory markers and blood-flows in the mesenteric and retrobulbar arteries without affecting blood pressure and endothelial function.