Bernadett Ujhelyi

Changes in the chemical barrier composition of tears in Alzheimer's disease reveal potential tear diagnostic biomarkers

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases, with increasing prevalence affecting millions of people worldwide. Currently, only autopsy is able to confirm the diagnosis with a 100% certainty, therefore, biomarkers from body fluids obtained by non-invasive means provide an attractive alternative for the diagnosis of Alzheimer`s disease. Global changes of the protein profile were examined by quantitative proteomics; firstly, electrophoresis and LC-MS/MS were used, thereafter, SRM-based targeted proteomics method was developed and applied to examine quantitative changes of tear proteins. Alterations in the tear flow rate, total tear protein concentration and composition of the chemical barrier specific to AD were demonstrated, and the combination of lipocalin-1, dermcidin, lysozyme-C and lacritin was shown to be a potential biomarker, with an 81% sensitivity and 77% specificity.

Effect of contact lens wear on the release of tear mediators in keratoconus.

Objectives: The release of different cytokines and mediators in tears of patients with keratoconus (KC) wearing contact lenses (CLs) may contribute to the pathology of KC. Methods: Cohort study was established in patients with KC wearing rigid gas permeable (RGP) CL (group I), patients with ametropia wearing silicone hydrogel (Si-Hi) CL (group II) and ametropic patients wearing RGP CL (group III). Results: Our findings indicate that before CL wear, the release of epidermal growth factor (EGF) and tissue-type plasminogen activator (t-PA) was attenuated, whereas matrix metalloproteinase (MMP)-9, interleukin (IL)-6, chemokine (C-C motif) ligand 5 (CCL5), IL-13, and plasminogen activator inhibitor (PAI)-1 were enhanced in KC compared with ametropes. An increasing linear trend over time was found for MMP-9, EGF, and CXCL8 in KC and MMP-9, MMP-13, IL-6, and CXCL8 in group III. Significant differences were observed in the linear trend over time between groups I and III for MMP-13 and tissue inhibitor of metalloproteinases (TIMP)-1; between groups I and II for MMP-9 and CXCL8; and between groups III and II for MMP-9, CXCL8, and MMP-13. In KC, the release of MMP-9 at week 6 and nerve growth factor (NGF) at 10 min was higher, but NGF at week 2 was lower than that in group II. The release of MMP-13 and NGF at week 2 and 6 were lower in the KC group as compared with group III, and similarly, with IL-6 and CXCL8 at week 2 and PAI at all time points. Conclusions: Contact lens wear can influence the levels and dynamics of various mediators in the tears of patients with KC that might have an impact on the progression of the disease.

Rapid response to and long-term effectiveness of anti-CD20 antibody in conventional therapy resistant Graves’ orbitopathy: A five-year follow-up study

Abstract The aim of this investigations was to study the effectiveness of anti-CD20 antibody therapy in Graves’ orbitopathy (GO) resistant to glucocorticoids. Five patients were entered in the study. The protocol required no improvement of orbital status after a recent course of glucocorticoids. Activity of GO was confirmed by three independent techniques: clinical activity score (CAS), 99mTc-labeled diethylene triamine pentaacetic acid (99mTc DTPA) single photon emission computed tomography and magnetic resonance imaging. Rituximab (RTX) was given as weekly infusions of 375 mg/m2 body surface area for four weeks. The mean follow-up period was 67 (range 58–81) months. Improvement of GO has been observed in all patients: CAS before therapy was 6.5 ± 1.7 and decreased to 3.4 ± 1.6 by one month (p < 0.05) and remained unchanged (3.2 ± 1.7) at 12 months. No further CAS change, in either direction, was detected during the yearly follow-up visits. The mean DTPA uptake before therapy was 16.52 ± 4.51 MBq/cm3 and decreased to 11.97 ± 2.36 MBq/cm3 at one year (p < 0.002). The mean of T2 relaxation times before and one year after therapy were 96.91 ± 17.61 ms and 84.29 ± 9.41 ms, respectively (p < 0.001). The mean serum TSH receptor antibody (TRAb) levels before therapy, at the one month and one year control visits were 7.4 ± 3.4 U/L, 5.6 ± 4.5 U/L and 1.7 ± 1.5 U/L, respectively (p < 0.004). No correlation between changes of TRAb and activity parameters has been found. Anti-CD20 treatment seems to influence positively the clinical course of GO, and this effect seems to be stable for five years. To our knowledge, this is the longest published follow-up of RTX treatment in GO.

Tear Mediators in Corneal Ectatic Disorders

Purpose To compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD) and keratoconus (KC). Methods We have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax), astigmatism, minimal radius of curvature (Rmin), corneal thickness (Apex and Min), indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration)) were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin). Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators’ (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP) -9, -13, tissue inhibitor of metalloproteinases (TIMP)-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor) concentrations were measured using Cytometric Bead Array. Results MMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005). The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively. Conclusion As far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD.

The impact of 99mTc-DTPA orbital SPECT in patient selection for external radiation therapy in Graves' ophthalmopathy

ObjectiveIn Graves’ ophthalmopathy (GO), there is a demand to differentiate the immunologically active disease state, when immunosuppressive therapy is necessary, from the inactive state, when the patient would not benefit from it. We measured the inflammatory activity in the retrobulbar region using 99mTc-diethylene triamine pentaacetic acid (DTPA) SPECT before and after external radiation to determine whether this method is suitable for predicting the effectiveness of this therapy. Materials and methodsThirty-two patients with suspected active GO were involved in this retrospective study. The initial image, DTPA uptake value (UV) and its change after therapy were assessed to monitor the effect of the therapy and investigate whether a pretreatment scan is capable of predicting the outcome. ResultsDepending on the change in DTPA UV after radiotherapy, three patient groups were formed: decreased, increased or minimally changed (less than 1×10−6 injected dose (ID)/ml). The initial DTPA UVs of these groups were significantly different (P<0.001). Improvement was observed mainly in patients with higher initial values. When comparing the groups with low (<12×10−6 ID/ml) versus high (≥12×10−6 ID/ml) initial uptake, an unexpected increase was observed in the first group after therapy (mean: +2.89±2.66×10−6 ID/ml), whereas the average change in the DTPA UV was negative in the latter group as anticipated (−2.24±4.47×10−6 ID/ml, P<0.00001). ConclusionWe found that in GO patients a high DTPA UV may predict the response to orbital radiation therapy. DTPA orbital SPECT may be a suitable technique for the selection of GO patients for radiation therapy.

Vascular endothelial growth factor levels in tears of patients with retinal vein occlusion

PurposeWe measured vascular endothelial growth factor (VEGF) levels in tear fluid and serum in patients with retinal vein occlusion (RVO).Patients and methodsEight patients with RVO due to secondary macular oedema were examined. VEGF levels were measured by enzyme-linked immunosorbent assay. All patients had a full ophthalmic examination (visual acuity, slit lamp biomicroscopy, perimetry, and fluorescein angiography). Central retinal thickness (CRT) was examined using optical coherence tomography (OCT). Tear and serum samples were collected and examinations were performed at diagnosis and 1 and 4 weeks later.ResultsVEGF levels in the tears of RVO eyes were significantly higher than in fellow eyes at diagnosis and after both 1 and 4 weeks (paired t test, p1 = 0.01, p2 = 0.02, p3 = 0.006). We found a weak but significant positive correlation between VEGF levels in tear fluid and serum of patients with RVO (r = 0.21), while this correlation tended to be stronger between the fellow eyes and serum levels (r = 0.33).ConclusionTo the best of our knowledge, we are the first to report an increased level of VEGF in the tear fluid of patients with RVO. Alterations of VEGF levels in tears may be useful for determining stages of RVO. This non-invasive and objective method may also be helpful for estimating the severity of macular oedema and efficacy of treatment.