Distribution of Cleaved SNAP-25 in the Rat Brain, following Unilateral Injection of Botulinum Neurotoxin-A into the Striatum.

In Parkinson's disease, hypercholinism in the striatum occurs, with the consequence of disturbed motor functions. Direct application of Botulinum neurotoxin-A in the striatum of hemi-Parkinsonian rats might be a promising anticholinergic therapeutic option. Here, we aimed to determine the spread of intrastriatally injected BoNT-A in the brain as well as the duration of its action based on the distribution of cleaved SNAP-25. Rats were injected with 1 ng of BoNT-A into the right striatum and the brains were examined at different times up to one year after treatment. In brain sections immunohistochemically stained for BoNT-A, cleaved SNAP-25 area-specific densitometric analyses were performed. Increased immunoreactivity for cleaved SNAP-25 was found in brain regions other than the unilaterally injected striatum. Most cleaved SNAP-25-ir was found in widespread areas ipsilateral to the BoNT-A injection, in some regions, however, immunoreactivity was also measured in the contralateral hemisphere. There was a linear relationship between the distance of a special area from the injected striatum and the time until its maximum averaged immunoreactivity was reached. Moreover, we observed a positive relationship for the area-specific distance from the injected striatum and its maximum immunoreactivity as well as for the connection density with the striatum and its maximum immunoreactivity. The results speak for a bidirectional axonal transport of BoNT-A after its application into the striatum to its widespread connected parts of the brain. Even one year after BoNT-A injection, cleaved SNAP-25 could still be detected.

An aggressive lactotroph pituitary tumor in a young male: A pituitary carcinoma without metastasis.

This case report concerns a 31-year-old male with an aggressive pituitary tumor who presented initially with bitemporal hemianopsia and slightly elevated prolactin. On magnetic resonance imaging of the brain, there was a sellar mass with parasellar invasion to the lateral aspects of the internal carotid arteries, compressing the optic chiasm. On histopathological analysis, the diagnosis was made of a densely granulated lactotroph pituitary tumor with a Ki67 proliferation rate of 15%, a mitotic count of 6/10 high-power fields, and p53 positivity. Based on these features, the tumor was classified as a grade 2b tumor according to the Trouillas classification, and a more aggressive behavior of the tumor could be expected. In order to anticipate a future need for alternative drug treatments, the following analyses were undertaken: MGMT methylation (present) as well as the expression of estrogen receptor (negative), programmed-death ligand 1 (60 - 70% positive tumor cells), vascular endothelial growth factor-A and somatostatin receptor 2 (both positive). There was regrowth of residual tumor tissue, and the treatment consisted thus far of repeat surgery, cabergoline, pasireotide, and radiotherapy. Chemotherapy with temozolomide could not yet be initiated due to a concurrent infertility treatment. This case is unique because the tumor displays atypical characteristics, both in terms of morphology and behavior. It also illustrates how pathologists can play an important role in determining the diagnosis, prognosis, and possibilities for targeted therapy.

[Statin intolerance and statin-associated muscular pain]. / Statinintoleranz und statinassoziierte Muskelschmerzen.

Statins are among the best studied drugs. Due to the extensive evidence regarding efficacy and safety, they are the cornerstone of lipid-lowering therapy. While the tolerability of statins in large blinded studies is at the placebo level, so-called statin intolerance (SI) is a frequent and complex problem in everyday clinical practice. Statin-associated muscular pain (SAMS) is most commonly reported. In many cases SI is associated with inadequate lowering of low-density lipoprotein (LDL) cholesterol (LDL-C), thereby increasing the cardiovascular risk. The diagnosis of SAMS is based on the exclusion of possible alternative causes of muscular symptoms and the exclusion of nocebo effects through a diagnostic strategy of discontinuation of statin treatment, observation and assessment of symptoms, followed by renewed administration of a different statin initially at a low dose with subsequent dose increase. A large proportion of patients with SI and SAMS can take statins permanently and without discomfort by this approach. If LDL­C lowering is insufficient, combination therapies are used. It is an important task of the prescribing physicians and all those involved in the treatment to increase the adherence to statins through appropriate communication. Numerous questions on SI remain open and are being addressed by an ongoing register.

The interrelations between PCSK9 metabolism and cholesterol synthesis and absorption.

Very few studies have investigated the interrelations between proprotein convertase subtilisin/kexin type 9 (PCSK9) metabolism, cholesterol synthesis, and cholesterol absorption. We aimed to address this issue in a large clinical trial of 245 patients with hypercholesterolemia. Serum lipids, PCSK9, lathosterol (cholesterol synthesis marker), campesterol, and sitosterol (cholesterol absorption markers) were measured before and 4-8 weeks after the start of treatment with PCSK9-antibodies (alirocumab or evolocumab). The patients had mean (standard error) LDL-cholesterol and PCSK9 concentrations of 3.87 (0.10) mmol/l and 356 (17) ng/ml, respectively. Eighty-four patients received no lipid-lowering pretreatment, 26 ezetimibe, 38 statins, and 97 ezetimibe + statins. Circulating PCSK9 increased in parallel with the potency of lipid-lowering pretreatment with circulating PCSK9 being highest in the ezetimibe + statin group (P < 0.001). Treatment with PCSK9-antibodies strongly decreased LDL-cholesterol, lathosterol, campesterol, and sitosterol (all P < 0.001) but hardly affected noncholesterol sterol to cholesterol ratios. Lipid-lowering pretreatment was not associated with the effects of PCSK9-antibodies on noncholesterol sterols (all P > 0.05). Summing up, circulating PCSK9 is increased by cholesterol synthesis and absorption inhibitors. Increased PCSK9 expression may partly explain the strong reductions of LDL-cholesterol achieved with PCSK9-antibodies after such pretreatment. On the other hand, treatment with PCSK9-antibodies does not significantly change the balance between cholesterol synthesis and absorption.

Long-term lipoprotein apheresis reduces cardiovascular events in high-risk patients with isolated lipoprotein(a) elevation.

BACKGROUND: Elevated lipoprotein(a) (Lp(a)) is an established risk factor for cardiovascular disease (CVD). To date, the only approved treatment to lower Lp(a) is lipoprotein apheresis (LA). Previous studies have demonstrated that LA is effective in reducing cardiovascular (CV) risk in patients with elevated low-density lipoprotein cholesterol (LDL-C) and/or Lp(a). Here we report our long-term experience with LA and its effectiveness in reducing CVD events in patients with elevated Lp(a). METHODS: This retrospective open-label, single-center study included 25 individuals with Lp(a) elevation >60 mg/dL and LDL-C < 2.59 mmol/L who had indication for LA. The primary endpoint of this study was the incidence of any CV event (determined by medical records) after initiation of LA. RESULTS: Mean LA treatment duration was 7.1 years (min-max: 1-19 years). Median Lp(a) was reduced from 95.0 to 31.1 mg/dL after LA (-67.3 %, p < 0.0001). Mean LDL-C was reduced from 1.85 to 0.76 mmol/L after LA (-58.9 %, p < 0.0001). Prior LA, 81 CV events occurred in total (0.87 events/patient/year). During LA, 49 CV events occurred in total (0.24 events/patient/year; -0.63, p = 0.001). Yearly major adverse cardiac event (MACE) rate was reduced from 0.34 to 0.006 (-0.33, p = 0.0002). Similar results were obtained when considering only individuals with baseline LDL-C below 1.42 mmol/L. CONCLUSION: In this observational study of a heterogeneous CV high-risk cohort with elevated Lp(a), LA reduced Lp(a) levels and was paralleled by a decrease in CV events and MACE. We recommend LA for patients with high Lp(a) who still have CV events despite optimal lipid-lowering medication and lifestyle changes.

The size of apolipoprotein (a) is an independent determinant of the reduction in lipoprotein (a) induced by PCSK9 inhibitors.

AIMS: Lipoprotein (a) [Lp(a)] is a lipoprotein species causatively associated with atherosclerosis. Unlike statins, PCSK9 inhibitors (PCSK9i) reduce Lp(a), but this reduction is highly variable. Levels of Lp(a) are chiefly governed by the size of its signature protein, apolipoprotein (a) [apo(a)]. Whether this parameter determines some of the reduction in Lp(a) induced by PCSK9i remains unknown. We aimed to investigate if the Lp(a) lowering efficacy of PCSK9i is modulated by the size of apo(a), which is genetically determined by the variable number of KIV domains present on that protein. METHODS AND RESULTS: The levels of Lp(a) and the size of apo(a) were assessed in plasma samples from 268 patients before and after treatment with PCSK9i. Patients were recruited at the Outpatient Lipid Clinic of the Charité Hospital (Berlin) between 2015 and 2020. They were hypercholesterolaemic at very high cardiovascular disease risk with low-density lipoprotein (LDL)-cholesterol levels above therapeutic targets despite maximally tolerated lipid-lowering therapy. Patients received either Alirocumab (75 or 150 mg) or Evolocumab (140 mg) every 2 weeks. Apo(a), apoB100, and apoE concentrations as well as apoE major isoforms were determined by liquid chromatography high-resolution mass spectrometry. Apo(a) isoforms sizes were determined by western blot. PCSK9i sharply reduced LDL-cholesterol (-57%), apoB100 (-47%), and Lp(a) (-36%). There was a positive correlation between the size of apo(a) and the relative reduction in Lp(a) induced by PCSK9i (r = 0.363, P = 0.0001). The strength of this association remained unaltered after adjustment for baseline Lp(a) levels and all other potential confounding factors. In patients with two detectable apo(a) isoforms, there was also a positive correlation between the size of apo(a) and the reduction in Lp(a), separately for the smaller (r = 0.350, P = 0.0001) and larger (r = 0.324, P = 0.0003) isoforms. The relative contribution of the larger isoform to the total concentration of apo(a) was reduced from 29% to 15% (P < 0.0001). CONCLUSIONS: The size of apo(a) is an independent determinant of the response to PCSK9i. Each additional kringle domain is associated with a 3% additional reduction in Lp(a). This explains in part the variable efficacy of PCSK9i and allows to identify patients who will benefit most from these therapies in terms of Lp(a) lowering.

PCSK9 Inhibitors in a German Single-Center Clinical Practice: Real-World Treatment of Patients at High Cardiovascular Risk Over 68 Weeks.

AIMS: Several the use of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) for patients at high/very high cardiovascular risk who are inadequately treated with maximally tolerated lipid-lowering therapies (LLTs). OBJECTIVES: We assessed the effectiveness and safety of the PCSK9i alirocumab and evolocumab in a single-center clinical practice for up to 68 weeks. METHODS: In this prospective, open-label study conducted in Germany, 635 enrolled patients were treated with alirocumab [75 or 150 mg every 2 weeks (Q2W)] or evolocumab (140 mg Q2W) according to European Society of Cardiology/European Atherosclerosis Society guidelines (low-density lipoprotein cholesterol [LDL-C] > 1.81/2.59 mmol/L (70/100 mg/dL), depending on cardiovascular risk]. Investigators were able to adjust LLTs, including PCSK9i, according to their own clinical judgment. The primary effectiveness endpoint was LDL-C reduction from baseline to week 68. RESULTS: At baseline, approximately 50% of patients were statin intolerant, and approximately 90% reported a history of cardiovascular disease. LDL-C reductions remained generally unchanged from weeks 4 to 68 in each treatment group. At week 68, LDL-C mean percentage changes from baseline were - 41.7% (alirocumab 75 mg Q2W), - 53.7% (alirocumab 150 mg Q2W), and - 54.1% (evolocumab 140 mg Q2W). LDL-C reduction was 7.1% greater in patients receiving statins than in those not receiving statins because of statin intolerance (P < 0.0001). PCSK9i consistently improved levels of other lipoproteins throughout. Overall, 47.1% of patients reported adverse events at week 68. CONCLUSIONS: Consistent with clinical trial findings, alirocumab and evolocumab improved lipid levels in a real-world setting in patients with high baseline LDL-C levels despite receiving maximally tolerated LLTs. PCSK9i were generally well-tolerated.

Treatment with PCSK9 inhibitors induces a more anti-atherogenic HDL lipid profile in patients at high cardiovascular risk.

BACKGROUND: Proprotein Convertase Subtilisin/Kexin type 9 inhibitors (PCSK9-I) have been reported to cause a moderate increase in high-density lipoprotein (HDL) cholesterol in human studies. We thus evaluated the effect of two approved PCSK9-I on the concentration and lipid composition of HDL particle subclasses. SUBJECTS AND METHODS: 95 patients (62.8 ± 10.3 years old, 58% men), with or without statin and/or ezetimibe treatment and eligible for PCSK9-I therapy, received either evolocumab (140 mg) or alirocumab (75 or 150 mg). Their HDL particle profiles were measured by NMR spectroscopy at baseline and after 4 weeks of PCSK9-I treatment. RESULTS: PCSK9-I treatment increased the level of HDL-C by 7%. The level of medium-sized HDL particles (M-HDL-P) increased (+8%) while the level of XL-HDL-P decreased (-19%). The lipid core composition was altered in the smaller S- and M-HDL-P, with a reduction in triglycerides (TG) and an enrichment in cholesterol esters (CE), whereas the for the larger XL- and L-HDL-P the relative CE content decreased and the TG content increased. Ezetimibe therapy differentially impacted the HDL particle distribution, independently of statin use, with an increase in S-HDL-P in patients not receiving ezetimibe. CONCLUSIONS: As S- and M-HDL-P levels are inversely related to cardiovascular risk, PCSK9-I treatment may result in a more atheroprotective HDL particle profile, particularly in patients not concomitantly treated with ezetimibe.