Decreased IgA1 response after primary oral immunization with live typhoid vaccine in primary IgA nephropathy.
INTRODUCTION: Patients with primary IgA nephropathy (IgAN) have an increased level of immunological memory to certain parenteral recall antigens. We recently found a deficient IgA1 immune response after intranasal challenge with a neo-antigen: cholera toxin subunit B. In the present study, we assessed the specific IgA1 and IgA2 antibody response in plasma, peripheral blood cells and mucosal secretions after primary enteral immunization. METHODS: Twenty eight IgAN patients, 26 patients with non-immunological renal disease and 32 healthy subjects were immunized orally with three sequential doses of live, attenuated, Salmonella typhi Ty21a. The humoral immune response in body fluids and antibody synthesis by circulating B cells was assessed in specific ELISAs and ELIPSAs respectively. RESULTS: Oral immunization resulted in significantly (P<0.0001) increased IgM, IgG, IgA, IgA1 and IgA2 responses in all groups, both in plasma and in circulating B cells in vitro. The IgA1 response in plasma was significantly (P<0.05) lower in IgAN patients, while no significant differences in IgM (P=0.36), IgG (P= 0.79) or IgA2 (P=0.45) responses were found as compared with matched control groups. The amount of IgA1 synthesized by circulating B cells tended to be lower in IgAN patients. No significant IgA response after oral immunization with S. typhi Ty21a was found in saliva (P=0.11) or tears (P=0.10). CONCLUSIONS: These data suggest an IgA1 hyporesponsiveness in patients with IgAN that is not only apparent after primary challenge of the nasal-associated lymphoid tissue but also after presentation to the gut. Previous results after parenteral recall immunization may be explained by assuming that IgAN patients require more frequent and/or longer exposure to IgA1-inducing antigens on their mucosal surfaces before they reach protective mucosal immunity. As a consequence, overproduction of IgA1 antibodies occurs in the systemic compartment, accompanied by an increased number of IgA1 memory cells. (+info)
Diseases associated with ocular surface abnormalities: the importance of reflex tearing.
AIM: To investigate the correlation between tear function tests and ocular surface integrity in patients with dry eye. METHODS: 297 dry eye patients (55 Sjogren's syndrome, two male and 53 female, average age 52.4 (SD 15.0) years, and 242 non-Sjogren's syndrome, 41 male and 201 female, average age 53.5 (14.1) years) were examined. The following tear function tests were performed: (1) cotton thread test, (2) Schirmer test with topical anaesthesia, (3) Schirmer test without anaesthesia, (4) Schirmer test with nasal stimulation, (5) tear clearance test, and (6) tear break up time (BUT). The ocular surface was evaluated by rose bengal and fluorescein staining. Correlation analysis was performed between each tear function index and vital staining scores. RESULTS: Among the six tear function tests, the Schirmer test with nasal stimulation correlated most with both of the vital stains (rho = 0.530 for rose bengal and 0.393 for fluorescein). The Schirmer test with or without anaesthesia correlated slightly with rose bengal staining, whereas tear clearance test and tear break up time slightly correlated with fluorescein staining. CONCLUSION: Vital staining of the ocular surface correlates most with reflex tearing measured by the Schirmer test with nasal stimulation. (+info)
Reflective meniscometry: a non-invasive method to measure tear meniscus curvature.
AIMS: To devise a method to measure tear meniscus curvature by a non-invasive specular technique. METHODS: A photographic system was devised. The system consisted of a camera and an illuminated target with a series of black and white stripes oriented parallel to the axis of the lower tear meniscus. The target was mounted on a flash gun close to the objective of a Brown macrocamera and calibrated using a graduated series of glass capillaries of known diameter, ground down to expose the inner wall. It was then applied to normal human eyes (n = 45) to measure the tear meniscus curvature. A video system was also assessed which provided qualitative online information about the tear meniscus. RESULTS: Using the photographic system, measured values for capillary radii were in excellent agreement with theoretical calculations (r2 = 0.996, p < 0.0001). The radii of curvature of lower tear menisci in normal human subjects (mean 0.365 (SD 0.153) mm, range 0.128-0.736; n = 45) were similar to those reported in the literature. Both systems demonstrated variations in meniscus shape. The video system provided stable images of human menisci over prolonged periods of time and promises to be useful for the analysis of dynamic changes in meniscus volume. CONCLUSIONS: Reflective meniscometry is a non-invasive technique providing quantitative information about tear meniscus shape and volume and of potential value in the study of ocular surface disease. (+info)
HPLC analysis of closed, open, and reflex eye tear proteins.
Changes in the closed, open and reflex eye tear proteins of normal subjects were compared and analysed. Tear proteins were resolved by high-performance liquid chromatography (HPLC) utilising both gel filtration (P-300 SW) and reverse-phase (C-18) columns and the HPLC fractions were further analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing and non-reducing conditions. The protein composition of the closed-eye tear was significantly different from that of the open and reflex-eye tear. Secretory IgA (sIgA) was the predominant protein in closed eye tears constituting 49% of the total protein compared to 11% in reflex tears, whereas lysozyme was the predominant protein (53%) in reflex tears. Levels of lactoferrin, lipocalin and lysozyme were relatively constant in both open and reflex tears. HPLC profiles of the closed-eye tears, upon continuous stimulation of lacrimal glands indicated that sIgA was significantly reduced whereas lactoferrin, lipocalin, and lysozyme were significantly increased. These results indicate that the tear composition upon waking attains that of the open eye within 4 to 5 minutes, and upon continuous stimulation this reflects the reflex-eye tear composition. It also indicates that mechanisms responsible for changes in concentration of constitutive and regulated tear protein with stimulus can be studied successfully using non-invasive methods to collect human tears. (+info)
Does androgen insufficiency cause lacrimal gland inflammation and aqueous tear deficiency?
PURPOSE: The current investigators have shown that androgen treatment suppresses inflammation and stimulates the function of lacrimal glands in mouse models of Sjogren's syndrome. Recently, others have hypothesized that androgen insufficiency induces an autoimmune process in lacrimal tissue, leading to inflammation, a Sjogren's syndrome-like pathology, and aqueous tear deficiency. The purpose of the present study was to test this hypothesis. METHODS: Lacrimal glands were obtained from adult testicular feminized (Tfm) and control mice; castrated rats, guinea pigs, and rabbits; and castrated rats without anterior or whole pituitary glands and were processed for histology and image analysis. Tear volumes were measured in mice, in patients taking antiandrogen medications, and in age-matched human control subjects. RESULTS: Tfm mice, which are completely resistant to classical androgen action, did not have increased lymphocyte infiltration in their lacrimal glands or decreased tear volumes. No inflammation was evident in lacrimal tissues of male or female rats, guinea pigs, or rabbits 12 to 31 days after castration, no inflammation existed in rat lacrimal glands 15 to 31 days after orchiectomy and pituitary removal, and no aqueous tear deficiency was apparent in patients receiving antiandrogen therapy. CONCLUSIONS: Androgen deficiency may promote the progression of Sjogren's syndrome and its associated lacrimal gland inflammation, meibomian gland dysfunction, and severe dry eye. However, androgen insufficiency alone does not cause lacrimal gland inflammation, a Sjogren's syndrome-like pathology in lacrimal tissue, or aqueous tear deficiency in nonautoimmune animals and humans. (+info)
Decreased tear lactoferrin concentration in patients with chronic hepatitis C.
BACKGROUND/AIMS: Decreased tear volume in patients with chronic hepatitis C has been reported in the literature. Lactoferrin is abundantly present in human tears, the main source of which is the acini of the lacrimal glands. In this study tear lactoferrin levels were measured to investigate the dry eye condition of patients with chronic hepatitis C. METHODS: Lactoferrin in tears/fluid was measured by a radial immunodiffusion assay in 42 patients with chronic hepatitis C. The rate of lacrimal secretion was determined by the cotton thread test. Rose bengal staining of the ocular surface was also performed. RESULTS: Only three patients out of 42 complained of dry eye sensation and, in 31 patients, six showed positive results on the rose bengal staining test of the ocular surface. The lactoferrin concentration of tear fluid in the chronic hepatitis C group (1.42 (SD 0.56) mg/ml) was significantly lower than in the control group (1.90 (0.62) mg/ml; p <0.00048). The cotton thread test results in the chronic hepatitis C group (12.9 (5. 5) mm) were significantly lower than in the control group (17.9 (5. 3) mm; p<0.00048). Also, in the chronic hepatitis C group, tear lactoferrin concentration correlated with the results of the cotton thread test (r = 0.35, p<0.05). CONCLUSION: Chronic hepatitis C patients showed both decreased tear volume, and decreased tear lactoferrin concentration. These findings suggest that there may be dysfunction of the lacrimal glands in patients with chronic hepatitis C, which may account for the mild dry eye. (+info)
Effects of experimental exposure to triethylamine on vision and the eye.
OBJECTIVES: To determine the effect of triethylamine (TEA) on the cornea and to evaluate the cause of blurred vision. To find the lowest observed effect concentration of exposure to TEA. METHODS: Four people were exposed to TEA for 4 hours at concentrations of 40.6, 6.5, and 3.0 mg/m3. Before and after every exposure, symptoms and ocular microscopy findings were recorded. Binocular visual acuity and contrast sensitivity at 2.5% contrast were also measured. Also, before and after the 40.6 mg/m3 exposure, corneal thickness was measured and ocular dimensions were recorded by ultrasonography, endothelial cells of the cornea were analysed, and serum and lacrimal specimens were collected for the analysis of TEA. RESULTS: After exposure to 40.6 mg/m3 TEA there was a marked oedema in the corneal epithelium and subepithelial microcysts. However, corneal thickness increased only minimally because of the epithelial oedema. The lacrimal concentrations of TEA were, on average (range) 41 (18-83) times higher than the serum TEA concentrations. The vision was blurred in all subjects and visual acuity and contrast sensitivity had decreased in three of the four subjects. After exposure to TEA at 6.5 mg/m3 two subjects experienced symptoms, and contrast sensitivity had decreased in three of the four subjects. There were no symptoms or decreases in contrast sensitivity after exposure to a TEA concentration of 3.0 mg/m3. CONCLUSIONS: TEA caused a marked oedema and microcysts in corneal epithelium but only minor increases in corneal thickness. The effects may be mediated by the lacrimal fluid owing to its high TEA concentration. Four hour exposure to a TEA concentration of 3.0 mg/m3 seemed to cause no effects, whereas exposure to 6.5 mg/m3 for the same period caused blurred vision and a decrease in contrast sensitivity. (+info)
Abnormal tear dynamics and symptoms of eyestrain in operators of visual display terminals.
OBJECTIVES: To clarify the relation between the prevalence of dry eye syndrome and subjective symptoms of asthenopia in visual display terminal (VDT) operators. METHOD: 722 VDT workers (242 subject workers with symptoms of asthenopia and 480 controls without such symptoms) without obvious organic ocular diseases received an ophthalmological examination consisting of refractometry and a tear function (phenol red thread) test. RESULTS: More than 30% of symptomatic workers were found to meet the criteria of dry eye, and the odds ratio compared with the controls was 4.61 (p < 0.001). This odds ratio was significantly greater than that obtained for refractive errors (2.31). CONCLUSIONS: Although this cross sectional study could not prove that dry eyes are the cause of asthenopia, the profound association of dry eyes with symptoms of asthenopia could be verified. It would be useful to carry out tear function tests in workers with symptoms of asthenopia. (+info)