lactoferrin and Conjunctivitis

Lactoferrin is a naturally occurring iron-binding glycoprotein, produced and secreted by mucosal epithelial cells and neutrophils in various mammalian species, including humans. It is typically found in fluids like saliva, milk and tears, where it reaches the maximum concentration. Thanks to its unique anti-inflammatory, antioxidant and antimicrobial activities, topical application of lactoferrin plays a crucial role in the maintenance of a healthy ocular surface system. The present review aims to provide a comprehensive evaluation of the clinical applications of lactoferrin in ocular diseases. Besides the well-known antibacterial effect, novel interest has been rising towards its potential application in the field of dry eye and viral infections. A growing body of evidence supports the antimicrobial efficacy of lactoferrin, which is not limited to its iron-chelating properties but also depends on its capability to directly interact with pathogen particles while playing immunomodulatory effects. Nowadays, lactoferrin antiviral activity is of special interest, since lactoferrin-based eye drops could be adopted to treat/prevent the new severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, which has conjunctivitis among its possible clinical manifestations. In the future, further data from randomized controlled studies are desirable to confirm the efficacy of lactoferrin in the wide range of ocular conditions where it can be used.

Topics: Animals; Anti-Infective Agents; Conjunctivitis; Coronavirus Infections; COVID-19; Dry Eye Syndromes; Humans; Lactoferrin; Pandemics; Pneumonia, Viral

To determine whether intolerance to contact lens wear is attributable to clinical or protein characteristics of the tear film.. Thirty-eight subjects participated; 20 were successful contact lens wearers and 18 had discontinued contact lens wear because of discomfort. Baseline tear film (no lens wear) was analyzed with a range of clinical measurements and protein analyses (lactoferrin, sIgA, and lysozyme). Comfort was determined after 6 hours of lens wear, and differences in tear film characteristics between subject groups were determined. In half of the subject group (n = 19), discriminant analysis was used to develop an equation for predicting the likelihood of intolerance to lens wear. Sensitivity and specificity were determined by testing the formula on the remaining subjects. These formulas were also tested on a separate group of subjects enrolled in a contact lens-wearing trial.. Tear volume (meniscus height and phenol red thread test) and tear stability (noninvasive tear break up time [NI-TBUT]) were significantly reduced in intolerant wearers (P < 0.05). A greater number of symptoms were reported by intolerant than by tolerant wearers (P < 0.05). Tolerance was associated with clinical but not protein characteristics of the tear film. Formulas best able to predict contact lens intolerance included NI-TBUT, number of symptoms experienced, and tear film meniscus height. Formulas had high sensitivity, and specificity which ranged from 29% to 57%.. Contact lens intolerance appears to be best predicted by a combination of clinical variables, including tear film stability, tear volume, and symptom reporting.

Topics: Adult; Conjunctivitis; Contact Lenses; Discriminant Analysis; Dry Eye Syndromes; Eye Proteins; Female; Humans; Immunoglobulin A, Secretory; Keratitis; Lactoferrin; Male; Muramidase; Osmolar Concentration; Patient Satisfaction; Phenolsulfonphthalein; Sensitivity and Specificity; Tears

The lacrimal film contains 6 to 10 g/l of proteins, 99% of which locally synthesized by the lacrimal glands. The study of these proteins allows us to explore the lacrimal function and to reveal an inflammatory process.. The lacrimal proteinic profile included the determination of total proteins and electrophoresis on agarose gel and, if necessary, specific determinations of albumin, lactoferrin, lysozyme and immunoglobulins using a nephelemetric technique. Normal values were established on a hundred of individual tears.. The electrophoretic proteinic profile may present different abnormalities, such as an inflammatory process, a functional alteration of the lacrimal glands or a dysproteinic abnormality of the tears. The specific determination of the principal lacrimal proteins allows us to accurately quantify each of them.. The electrophoresis of the tears on an agarose gel reveals the presence of an inflammatory process or the quantitative or qualitative alteration of the lacrimal function. The immuno-nephelemetric determination of the most important proteins which are involved in theses mechanisms gives an accurate quantitative measurement of proteins and allows biological follow-up of the disease.

Topics: Albumins; Blood-Aqueous Barrier; Conjunctivitis; Dry Eye Syndromes; Electrophoresis, Agar Gel; Humans; Immunoglobulin A; Lacrimal Apparatus; Lactoferrin; Muramidase; Proteins; Tears

Human tear proteins in the conjunctival sac were separated on the basis of the differences in their isoelectric points and molecular weights using micro two-dimensional electrophoresis combined with immunoblotting. The two-dimensional electrophoretic patterns of tear proteins from patients with conjunctivitis were compared with those from normal individuals. We also measured integrated intensities of seven protein spots, lactoferrin (LF), albumin and five specific tear proteins (STP), to examine differences in the amounts of these proteins in tears from normal individuals of different sexes. In the tears from patients with conjunctivitis, secretory immunoglobulin A (IgA), LF and STP spots were stained more weakly, whereas the albumin spot was stained more strongly as compared with those from normal individuals. Furthermore, haptoglobin and IgG spots appeared in the tears from patients with conjunctivitis. These were more prominent in the tears from patients with severe conjunctivitis. There were significant differences in the amounts of LF and two kinds of STPs in the different sexes. The amounts of these proteins were larger in females.

Topics: Adult; Conjunctivitis; Electrophoresis, Gel, Two-Dimensional; Eye Proteins; Female; Humans; Immunoblotting; Lactoferrin; Male; Reference Values; Rosaniline Dyes; Sex Characteristics; Staining and Labeling; Tears

Lactoferrin, an iron complexing protein in normal tears, is an important component of the nonspecific host defense system of the external eye. We measured tear lactoferrin levels in patients with contact lens-induced giant papillary conjunctivitis (GPC) by an enzyme-linked immunosorbent assay (ELISA). Patients with active GPC (N = 26) had significantly reduced tear levels of lactoferrin (0.876 +/- 0.42 mg/ml) compared with normal individuals (N = 12; 1.73 +/- 0.46 mg/ml, P less than 0.0003) and the control contact lens wearers' group (N = 11; 1.57 +/- 0.92 mg/ml, P less than 0.003). Patients with vernal conjunctivitis (N = 10), an ocular disease with similar histopathology, had slightly reduced concentrations of tear lactoferrin (1.22 +/- 0.59 mg/ml). Patients with inactive GPC (N = 7) had normal tear levels of lactoferrin (1.33 +/- 0.49 mg/ml). The lactoferrin to total protein ratio in the tears was significantly reduced in patients with GPC compared to normal subjects, control contact lens wearers, and patients with inactive GPC. The decreased tear levels of lactoferrin in patients with GPC may contribute to increased coating of lenses with bacteria and their products and enhanced ocular inflammation which may play a role in the pathogenesis of GPC.

Topics: Adenoviridae Infections; Conjunctivitis; Conjunctivitis, Allergic; Eye Proteins; Humans; Lactoferrin; Lactoglobulins; Tears

The levels of total protein in tears from healthy donors, conjunctivitis vernalis patients, and conjunctivitis follicularis patients, were 625, 1370 and 1160 mg% respectively. Serum albumin accounted for 3.3%, 43% and 67% of the total protein of tears from these groups, and the level of proteins probably synthesized by the lacrimal gland, was in tears from conjunctivitis follicularis patients only half the level in normal tears. By crossed immunoelectrophoresis with intermediate gel, 10 antigenic species could be recognized in normal tears, and of these the following were identified: Lysozyme, IgA, lactoferrin and serum albumin. In tears from patients with conjunctivitis vernalis three more immunoprecipitates were observed, of which one was due to IgG. No lysozyme could be demonstrated in tears from a case of conjunctivitis sicca by immunoelectrophoresis. In tears from healthy donors the mean level of IgA was 20 mg%, of IgG 3 mg%, and IgM could not be demonstrated. Rabbit anti-tear immunoglobulin did not precipitate a standard of human IgM in double immunodiffusion. In cases of conjunctivitis vernalis and follicularis the mean levels were increased to 80 and 114 mg% IgG, and 11 and 14 mg% IgM, but IgA was increased only to 32 and 41 mg%. It is assumed that the level of IgA in normal tears is almost entirely due to local synthesis, while serum albumin and other immunoglobulins may have escaped from the circulation by molecular sieving. The increased levels of immunoglobulins in inflammatory diseases is probably due to transudation. However, in blepharoconjunctivitis patients several tear samples with a high IgM and a low or zero level of IgG could be demonstrated. Possible explanations for this phenomenon are discussed.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Conjunctivitis; Female; Humans; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Lactoferrin; Male; Middle Aged; Muramidase; Proteins; Serum Albumin; Tears