Prevalence, Duration and Severity of Parkinson's Disease in Germany: A Combined Meta-Analysis from Literature Data and Outpatient Samples.

BACKGROUND: Epidemiological data on the prevalence of Parkinson's disease (PD) in Germany are limited. The aims of this study were to estimate the age- and gender-specific prevalence of PD in Germany as well as the severity and illness duration. SUMMARY: A systematic literature search was performed in 5 different databases. European studies were included if they reported age- and gender-specific numbers of prevalence rates of PD. Meta-analytic approaches were applied to derive age- and gender-specific pooled prevalence estimates. Data of 4 German outpatient samples were incorporated to calculate the proportion of patients with PD in Germany grouped by Hoehn and Yahr (HY) stages and disease duration. In the German population, 178,169 cases of PD were estimated (prevalence: 217.22/100,000). The estimated relative illness duration was 40% with less than 5 years, 31% with 5-9 years, and 29% with more than 9 years. The proportions for different HY stages were estimated at 13% (I), 30% (II), 35% (III), 17% (IV), and 4% (V), respectively. Key Message: We provide an up-to-date estimation of age- and gender-specific as well as severity-based prevalence figures for PD in Germany. Further community studies are needed to estimate population-based severity distributions and distributions of non-motor symptoms in PD.

Local inactivation of sphingosine 1-phosphate in lymph nodes induces lymphopenia.

Sphingosine 1-phosphate (S1P) initiates T and B cell exit from lymphoid tissues by activating the S1P(1) receptor on lymphocytes. To define the mechanistic details of this ligand-receptor interaction, the biological activity of the S1P-blocking Ab Sphingomab was investigated. Treatment of mice with Sphingomab resulted in blood B and T cell lymphopenia. Although Sphingomab blocked S1P(1)-mediated calcium flux and receptor downregulation by S1P in vitro, plasma from Sphingomab-treated mice demonstrated a 4-fold increase in S1P concentration and largely retained its stimulating activity on S1P receptors. Plasma-borne S1P was obviously not sufficiently inactivated by Sphingomab to account for the observed lymphopenia. Therefore, we addressed the local S1P-blocking activity of Sphingomab in spleen and peripheral lymph nodes (pLNs) as a potential cause of PBL depletion. Transwell chemotaxis assays revealed the migration of freshly isolated splenocytes, but not pLN cells to S1P. However, chemotaxis of pLN cells was regained after culture in S1P-low medium, and pLN cells isolated from Sphingomab-treated mice also revealed enhanced chemotaxis to S1P, indicating substantial local inactivation of S1P in pLN after Sphingomab treatment. We conclude that treatment with the S1P-blocking Ab Sphingomab induces lymphopenia by inactivating S1P locally in pLN and not systemically in plasma. Consequently, the presence of local S1P amounts in secondary lymphoid organs contributes to B and T cell egress.

Redistribution of sphingosine 1-phosphate by sphingosine kinase 2 contributes to lymphopenia.

Sphingosine kinases (SKs) 1 and 2 produce high concentrations of sphingosine 1-phosphate (S1P) in blood and lymph. In contrast, S1P concentrations in lymphoid tissues are kept low by the S1P-degrading activity of the S1P-lyase. These differences in S1P concentrations drive lymphocyte circulation. Inhibition of the S1P-lyase prevents lymphocyte egress and causes lymphopenia because of increased S1P levels in lymphoid tissues. In this study, we investigated the source of this accumulating S1P in lymphoid tissues by using SK2-deficient (SK2(-/-)) mice. In contrast to wild-type mice, SK2(-/-) mice exhibited attenuated lymphopenia after S1P-lyase inhibition by 4-deoxypyridoxine (DOP). Consistently, S1P concentrations were only modestly increased in lymphoid tissues of SK2(-/-) mice compared with a significantly higher increase in wild-type mice after DOP treatment. Low S1P concentrations in lymphoid tissues of DOP-treated SK2(-/-) mice were accompanied by higher S1P concentrations in blood, suggesting that SK2(-/-) mice display defective S1P transport from blood into lymphoid tissues. To investigate this potential new role of SK2, RBCs loaded with traceable C17-S1P were transfused into wild-type and SK2(-/-) mice, resulting in much higher C17-S1P concentrations in blood of SK2(-/-) mice compared with wild-type mice 2 h after transfusion. Moreover, cocultures of RBCs with mouse splenocytes and endothelial cells demonstrated that SK2 regulated cellular uptake of S1P from RBCs. Collectively, our data suggest that S1P in lymphoid tissues derives from blood and point to an essential role of SK2 in S1P transport.

Do we start too late? Insights from the real-world non-interventional BALANCE study on the present use of levodopa/carbidopa intestinal gel in advanced Parkinson's disease in Germany and Switzerland.

INTRODUCTION: Advanced Parkinson's disease is characterized by motor and non-motor fluctuations to oral dopamine replacement therapy. The BALANCE study evaluated the clinical practice in Germany and Switzerland, when patients eligible for levodopa/carbidopa intestinal gel (LCIG) therapy decided to either switch to LCIG or to stay on optimized standard of care (SoC) oral therapy as a non-randomized regular clinical decision. METHODS: In this non-interventional, multicenter, prospective observational study, patients were recruited between 2015 and 2020. We obtained comprehensive baseline characteristics in both groups. As primary endpoint, we evaluated whether LCIG led to higher quality-of-life (QoL) improvement than SoC after 12 months. As secondary endpoints, we studied several motor and non-motor outcomes. RESULTS: About half of the 137 patients decided for LCIG treatment (n = 73, 53.5%). Those were aged >70 years more often, had more advanced disease stage, higher burden of motor and neuropsychiatric symptoms, and cognitive impairment including dementia compared to SoC. QoL change after 12 months did not differ between groups (P = 0.286). The LCIG group improved in secondary outcomes, including the UPDRS III in ON, UPDRS IV, Unified Dyskinesia Rating Scale, and Non-Motor Symptoms Scale. Clinical Global Impression-Improvement scale improved in 78.0% and 19.5% of patients receiving LCIG and SoC, respectively. Caregiver burden remained stable in LCIG but worsened with SoC. CONCLUSION: In current practice, patients and physicians delayed LCIG treatment and started substantially beyond the established indication criteria. This practice bears the risk to produce inferior results compared to the results from existing high-level evidence.

Down-regulation of S1P1 receptor surface expression by protein kinase C inhibition.

The sphingosine 1-phosphate receptor type 1 (S1P(1)) is important for the maintenance of lymphocyte circulation. S1P(1) receptor surface expression on lymphocytes is critical for their egress from thymus and lymph nodes. Premature activation-induced internalization of the S1P(1) receptor in lymphoid organs, mediated either by pharmacological agonists or by inhibition of the S1P degrading enzyme S1P-lyase, blocks lymphocyte egress and induces lymphopenia in blood and lymph. Regulation of S1P(1) receptor surface expression is therefore a promising way to control adaptive immunity. Hence, we analyzed potential cellular targets for their ability to alter S1P(1) receptor surface expression without stimulation. The initial observation that preincubation of mouse splenocytes with its natural analog sphingosine was sufficient to block Transwell chemotaxis to S1P directed subsequent investigations to the underlying mechanism. Sphingosine is known to inhibit protein kinase C (PKC), and PKC inhibition with nanomolar concentrations of staurosporine, calphostin C, and GF109203X down-regulated surface expression of S1P(1) but not S1P(4) in transfected rat hepatoma HTC(4) cells. The PKC activator phorbol 12-myristate 13-acetate partially rescued FTY720-induced down-regulation of the S1P(1) receptor, linking PKC activation with S1P(1) receptor surface expression. FTY720, but not FTY720 phosphate, efficiently inhibited PKC. Cell-based efficacy was obvious with 10 nm FTY720, and in vivo treatment of mice with 0.3-3 mg/kg/day FTY720 showed increasing concentration-dependent effectiveness. PKC inhibition therefore may contribute to lymphopenia by down-regulating S1P(1) receptor cell surface expression independently from its activation.

Erythrocytes serve as a reservoir for cellular and extracellular sphingosine 1-phosphate.

Sphingosine 1-phosphate (S1P) in blood is phosphorylated, stored, and transported by red blood cells (RBC). Release of S1P from RBC into plasma is a regulated process that does not occur in plasma- or serum-free media. Plasma fractionation and incubations with isolated and recombinant proteins identified high density lipoprotein (HDL) and serum albumin (SA) as non-redundant endogenous triggers for S1P release from RBC. S1P bound to SA and HDL was able to stimulate the S1P(1) receptor in calcium flux experiments. The binding capability of acceptor molecules triggers S1P release, as demonstrated with the anti-S1P antibody Sphingomab. More S1P was extracted from RBC membranes by HDL than by SA. Blood samples from anemic patients confirmed a reduced capacity for S1P release in plasma. In co-cultures of RBC and endothelial cells (EC), we observed transcellular transportation of S1P as a second function of RBC-associated S1P in the absence of SA and HDL and during tight RBC-EC contact, mimicking conditions in tissue interstitium and capillaries. In contrast to S1P bound to SA and HDL, RBC-associated S1P was significantly incorporated by EC after S1P lyase (SGPL1) inhibition. RBC-associated S1P, therefore, has two functions: (1) It contributes to the cellular pool of SGPL1-sensitive S1P in tissues after transcellular transportation and (2) it helps maintain extracellular S1P levels via SA and HDL independently from SGPL1 activity.

Accumulation of fingolimod (FTY720) in lymphoid tissues contributes to prolonged efficacy.

The immunomodulator fingolimod (FTY720) induces lymphopenia by inhibiting lymphocyte egress from thymus and secondary lymphoid organs (SLOs). It is phosphorylated mainly by sphingosine kinase (SK) 2 in vivo. FTY720-phosphate (FTY-P) activated and rapidly internalized S1P(1), which is the major sphingosine 1-phosphate (S1P) receptor for mediating lymphocyte egress. Although FTY-P is thought to be the active metabolite for triggering the onset of lymphopenia, nonphosphorylated FTY720 was much more potent in inhibiting cellular calcium flux and splenocyte chemotaxis via S1P(1) than FTY-P after preincubation. Determination of both compounds by liquid chromatography coupled to mass spectrometry revealed efficient uptake and accumulation of FTY720 but not FTY-P by splenocytes. Coculture experiments of B and T cells with and without FTY720 pretreatment led to rapid cellular transfer and phosphorylation by mouse lymphocytes. The presence of FTY720 in lymphoid tissues of FTY720-treated SK2-deficient mice without onset of lymphopenia excluded a potential role of the nonphosphorylated compound for lymphocyte egress. Local concentrations of both phosphorylated and nonphosphorylated FTY720 were much higher in lymphoid tissues than in blood. Therefore, we conclude that cellular accumulation of FTY720 generates a reservoir in thymus and SLOs, leading to sustained FTY-P production and activation of S1P(1) within tissues.

Selective activation of G alpha i mediated signalling of S1P3 by FTY720-phosphate.

The immune modulator FTY720 is phosphorylated in vivo to FTY720 phosphate (FTY-P), which activates four sphingosine 1-phosphate (S1P) receptors including S1P(3). Upon activation with S1P, S1P(3) couples to G(i)- and G(q)-protein-dependent signalling pathways. Here we show that FTY-P selectively activates the S1P(3)-mediated and G(i)-coupled inhibition of adenylyl cyclase. Contemporaneously, it antagonizes the S1P-induced activation of G(q) via S1P(3) in intracellular calcium flux measurements, GTP-binding experiments, and flow cytometric analyses of activation-induced receptor down-regulation. In contrast to S1P, pre-treatment with FTY-P did not desensitize S1P-induced calcium flux or chemotaxis via S1P(3). The lack of receptor desensitization prevented S1P(3)-mediated migration to FTY-P. Human umbilical vein endothelial cells express S1P(1) and S1P(3), and respond to S1P and FTY-P by ERK1/2 phosphorylation and by intracellular calcium release in a pertussis toxin-sensitive manner. But whereas a mixture of S1P and FTY-P was not affecting ERK1/2 phosphorylation, the intracellular calcium flux was hampered with increasing amounts of FTY-P, which points to a cross-talk between S1P(1) and S1P(3). FTY-P is therefore one of the rare ligands which bind to a receptor that couples multiple G-proteins but selectively activates only one signalling pathway.

S1P-lyase independent clearance of extracellular sphingosine 1-phosphate after dephosphorylation and cellular uptake.

Sphingosine 1-phosphate (S1P) is the natural ligand for a specific family of G protein-coupled receptors (-Rs). The type 1 S1P-R (S1P(1)) is important for lymphocyte egress, and blood-borne S1P as the natural ligand for S1P(1) is involved in the maintenance of lymphocyte circulation. This report reveals that extracellular S1P was cleared by all tested primary cells and cell lines with exponential progression. Clearance of S1P, but not sphingosine (Sph) was inhibited with the protein phosphatase inhibitor sodium orthovanadate. Fluorescence microscopy and flow cytometry using fluorescently labeled S1P and Sph showed a major cellular uptake of Sph, but not S1P. HPLC-analyses with C17-Sph demonstrated that cellular Sph accumulation was transient in tested cell lines, but enduring in mouse splenocytes. Sub cellular fractionation resulted in dephosphorylation of S1P to Sph by nuclear, membrane, and cytosolic fractions. Degradation of Sph however only occurred in combined membrane and cytosolic fractions. Inhibitors for Sph kinases 1/2, ceramide synthase, and S1P-lyase, as well as S1P-lyase deficiency did not block clearance of extracellular S1P. In vivo experiments revealed a transient increase in plasma S1P levels after single intravenous injection into C57BL/6 mice. This exogenously added S1P was cleared within 15-30 min in contrast to ex vivo incubation of whole blood which required more than 8 h for comparable clearance from plasma. Our data thus show that extracellular S1P is dephosphorylated and subsequently converted by cells, which appears to be important for clearance of the signaling molecule S1P in the local tissue environment after infections or injuries.

An Observational Study of the Effect of Levodopa-Carbidopa Intestinal Gel on Activities of Daily Living and Quality of Life in Advanced Parkinson's Disease Patients.

INTRODUCTION: Continuous delivery of levodopa-carbidopa intestinal gel (LCIG) by percutaneous endoscopic gastrojejunostomy (PEG-J) in advanced Parkinson's disease (PD) patients reduces variability in plasma levels, providing better control of motor fluctuations ("on" and "off" states). The MONOTREAT study assessed the effect of LCIG on activities of daily living, motor and non-motor symptoms, and quality of life in advanced PD patients. METHODS: This prospective, observational study included patients with advanced, levodopa-responsive PD with either 2-4 h of "off" time or 2 h of dyskinesia daily. Patients received LCIG via PEG-J for 16 h continuously. Effectiveness was assessed using Unified PD Rating Scale parts II and III, the Non-Motor Symptom Scale, and the PD Questionnaire-8. RESULTS: The mean (SD) treatment duration was 275 (157) days. Patients experienced significant improvement from baseline in activities of daily living at final visit (p < 0.05) as well as at months 3 and 6 (p < 0.0001). Patients also experienced significant improvements from baseline in quality of life and non-motor symptoms at all time points (p < 0.001 for all). Specifically, patients manifested significant improvements in mean change from baseline at every study visit in five of nine non-motor symptom score domains: sleep/fatigue, mood/cognition, gastrointestinal tract, urinary, and miscellaneous. One-third of patients (32.8%) experienced an adverse event; 21.9% experienced a serious adverse event; 11.1% discontinued because of an adverse event. CONCLUSION: This study demonstrated significant and clinically relevant improvements in measures of activities of daily living, quality of life, and a specific subset of non-motor symptoms after treatment with LCIG. FUNDING: AbbVie Inc.