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A Kijlstra

Publications and source records attributed to A Kijlstra.

At least 199 records · Page 11Linked to original sources
PubMed1987

Autoimmunity against corneal antigens. II. Accessibility of the 54 kD corneal antigen for circulating antibodies.

Autoantibodies against corneal epithelium antigens are frequently found in patients with corneal diseases, but also in patients with uveitis. To investigate whether these autoantibodies play a primary role in the pathogenesis of corneal disease we studied the distribution of a 54 kD corneal antigen (isolated in a previous study) within the eye. Animal experiments were performed to determine the accessibility of this antigen by its corresponding antibody. Immunohistochemistry showed that the 54 kD corneal antigen was abundantly present in the rat corneal and conjunctival epithelium. A high concentration of this antigen was seen just above the nuclei in the basal cell layer of the corneal epithelium. The antigen could also be detected in the keratocytes of the corneal stroma, the corneal endothelium and the lens epithelium. The 54 kD corneal antigen was not detected in other parts of the eye, nor could it be found in the rat liver, kidney, spleen, lung or skeletal muscle. Incubation of intact rat eyes with antiserum against the 54 kD corneal antigen in vitro, resulted in a weak binding of immunoglobulins to the corneal surface epithelium cells. Passive transfer experiments, whereby rats received an intravenous injection of antiserum against the 54 kD corneal antigen resulted in a weak deposition of immunoglobulins in the corneal stroma and sclera. However, no antibodies were bound to the corneal epithelium. These observations show that although antibody production to corneal epithelium antigens is easily triggered, these antibodies do not reach the corneal epithelium.

Animals↗
PubMed1987

Humoral and cellular immune responsiveness to human S-antigen in uveitis.

Purified human retinal S-antigen (S-ag) was used to investigate the occurrence of humoral and cellular autoimmune reactions against S-ag in uveitis patients. With a sensitive ELISA method anti-S-ag antibodies could be detected in the sera of 28% of the uveitis patients. No difference was found between patients with posterior or panuveitis (31 out of 117 positive) and patients with anterior or intermediate uveitis (16 out of 52 positive). Similar frequencies and levels of anti-S-ag autoantibodies were also found among healthy controls (6/20) and patients who had undergone cataract surgery (6/17). Immunoblotting with purified S-ag and with whole human retinal extract confirmed the presence of anti-S-ag antibodies in uveitis and control sera. Moreover, antibodies against various other retinal proteins could also be demonstrated in patients and controls, without being particularly enhanced in uveitis. The cellular immune responsiveness was tested by measuring the production of migration inhibitory factor (MIF) during overnight culture of peripheral mononuclear cells with the antigen. None of 18 healthy controls responded, whereas 17 positive reactions were observed in the group of 44 uveitis patients. The highest frequencies were found in patients with posterior (5/12) or pan- (7/12) uveitis, while of the responders with anterior (2/8) or intermediate (3/12) uveitis, three had disorders affecting the retina. Thus, cellular autoimmune responsiveness to S-ag is apparently associated with posterior and pan-uveitis, and might also occur in non-uveitic retinal disorders, whereas the occurrence of anti-S-ag antibodies is probably not at all pathognomic for uveitis.

Adolescent↗
PubMed1987

Guinea pig tears contain lactoferrin and transferrin.

The ironbinding protein lactoferrin is one of the main proteins in human tears. Until now no animal models are available to investigate the exact role of this protein on the ocular surface. We have therefore started investigations concerning the presence of ironbinding proteins in various laboratory animals. In this report the presence of lactoferrin and transferrin in guinea pig tears was investigated using an iron-binding assay, Ouchterlony immunodiffusion, ELISA and immunoblotting techniques. Guinea pig tears contain a weak ironbinding activity, which is markedly lower than that observed in human tears. Lactoferrin and transferrin were identified using the fact that guinea pig lactoferrin reacts with monoclonal and polyclonal anti human lactoferrin antibodies and that guinea pig serum transferrin reacts with an anti rabbit transferrin serum. SDS-PAGE and immunoblotting showed that, guinea pig lactoferrin and transferrin have a similar molecular weight of approximately 75 kD, which is however, definitely smaller than that of human lactoferrin and transferrin (80 kD). The amount of lactoferrin in guinea pig tears, measured in an ELISA using anti human lactoferrin antisera, was very low (equalling 600 mg/ml of human lactoferrin immunoreactivity). Transferrin in guinea pig tears was measured with an ELISA in 10 guinea pigs and resulted in a mean concentration of 22.3 micrograms/ml. The species comparisons performed until now indicate that human tears remain unique in their high content of lactoferrin.

Animals↗
PubMed1987

Inhibition of hydroxyl radical formation by human tears.

The effect of human tears on oxygen radical formation was investigated using xanthine-xanthine oxidase as the oxygen radical generating system. Superoxide (O2.-) and hydrogen peroxide (H2O2) were measured using ferricytochrome c as indicator. OH. formation was monitored by measuring the hydroxylation of salicylate. Addition of traces of iron (Fe3+) and chelator (EDTA) was a prerequisite for OH. formation in this system. Human tears did not detectably affect O2.- or H2O2 formation but markedly inhibited OH. formation. Tears obtained from eight different individuals all showed a marked inhibitory effect on OH. formation, whereby only a small individual variation was observed. During separation of human tears by gelfiltration on a Sephadex G75 column, three protein peaks eluted from the column. The first contained lactoferrin, the second as yet unidentified material, and the third lysozyme. Inhibitory activity on OH. formation coincided with the first protein peak and also with fractions eluting after the protein peak containing lysozyme. The major inhibition on OH. formation was seen in these latter fractions, which contain small organic and anorganic substances. The fact that ascorbic acid could not be detected in human tears and that it did not affect formation of OH. in this investigation's assay system indicates that this compound was not involved in the observed low molecular weight inhibitory effect. Analysis of various cations suggested that the low molecular weight inhibitory effect could largely be ascribed to tear calcium. Tear calcium binds to EDTA and thus possibly prevents formation of the essential catalytic iron-EDTA complex. Experiments using purified human milk lactoferrin showed, that this protein, which is abundantly present in human tears, can inhibit OH. formation in the model used here. The inhibitory effect of lactoferrin was counteracted by increasing the iron concentration in the reaction mixtures. These findings suggest that tear lactoferrin may play an important role in the protection of the ocular surface against OH. induced damage.

Eye Proteins↗
PubMed1986

Clinical and experimental studies concerning circulating antibodies to corneal epithelium antigens.

Corneal epithelium antibodies were detected in patients with corneal melting disease (55%), uveitis (42%), corneal transplantation (42%) and marginal furrow disease (20%). These antibodies were not found in herpetic keratitis patients. In control groups, consisting of ocular surgery patients (glaucoma, retinal detachment and cataract) and persons without a history of ocular disease, approximately 4% of the subjects had these antibodies. To investigate the possible role of trauma to the cornea as an initiator of corneal epithelium antibodies, these antibodies were determined in rabbits after alkaline burns were made on the cornea. These antibodies were detected one week later and disappeared after six weeks. Serum from three patients with corneal melting disease and corneal transplantation containing a high antibody titre against corneal epithelium were used to isolate corneal epithelium antigens. A 54 kD and a 17 kD corneal epithelium antigen were isolated. The incidence of autoantibodies directed against these antigens was investigated in patients with corneal melting disease, uveitis and corneal transplantation using an ELISA. 50% of the sera positive in the immunofluorescence test were positive in the ELISA.

Adult↗
PubMed1986

Aqueous chamber taps in toxoplasmic chorioretinitis.

The clinical value of the determination of toxoplasma antibodies in anterior chamber taps was evaluated in 12 posterior uveitis patients suspected of a toxoplasmic retinochoroiditis, in four patients with Fuchs's heterochromia and in 31 cataract patients. The posterior uveitis patients all had marked inflammation of the vitreous obstructing the examination of the fundus of the time of aqueous humour aspiration. The clinical diagnosis toxoplasmic uveitis (n = 9) was made after the inflammation of the vitreous had subsided and fundus examination became possible again. Paired serum and aqueous samples were tested for total immunoglobulin levels and toxoplasma antibodies. Eight of the nine clinical toxoplasmic uveitis patients had detectable toxoplasma antibodies in their aqueous, whereas none of the other seven uveitis patients were positive. All of these eight toxoplasmic uveitis patients had a coefficient above 1.5. Of the 31 control patients only one had a positive antibody titer at a dilution of 1/2 with a corresponding coefficient of 1.1. This study shows that aqueous humour examination for toxoplasma antibodies is a valuable diagnostic tool in a selected group of posterior uveitis patients.

Antibodies↗
PubMed1986

HLA-antigens in the human uvea.

With the use of monoclonal antibodies in an indirect immunofluorescence technique we studied the distribution of Class I (HLA-ABC and B27) and Class II (HLA-DR) antigens in the human uvea. W6/32, directed against the core of HLA-ABC antigens, was used to study the distribution of Class I antigens. The anterior border layer of the iris, the non-pigmented and pigmented epithelium and the external basement membrane of the ciliary body and the vascular endothelium in the uvea showed a positive staining for Class I antigens. B27/M1, directed against an epitope of the HLA-B27 antigen, and the control antibody A11/Aw24, which was directed against an epitope of HLA-A11, revealed the same distribution pattern in respectively HLA-B27 and HLA-A11 positive donor eyes. The intensity of their staining was much weaker than the staining with W6/32. Class II antigens were studied with OkIa1, an antibody directed against the core of HLA-DR antigens. HLA-DR antigens were detectable on single cells scattered throughout the entire uvea. These cells did not seem to relate to any anatomical entity. No staining for Class II antigens was seen in the uveal blood vessel endothelium. The expression of HLA-antigens in the uvea is compatible with the distribution in other tissues. These findings suggest that the expression of HLA-B27 in the human uvea does not explain why the eye is one of the target tissues in HLA-B27 associated disease.

Adolescent↗
PubMed1986

The use of HLA-B27 as a diagnostic and prognostic aid in acute anterior uveitis (AAU) in The Netherlands.

Acute anterior uveitis (AAU) may be considered to be one manifestation of the seronegative spondylarthropathies of which ankylosing spondylitis (AS) is the prototype, especially when the patient is HLA-B27 positive. However, it is not yet clear under which circumstances a patient with AAU should be referred to the rheumatologist. In a retrospective study we evaluated the management of 68 consecutive HLA-B27+ AAU patients from a rheumatologic point of view. Although the majority (73%) showed rheumatic problems, only half (52%) of the patients was referred to a rheumatologist, due to problems in evaluation of clinical history and of x-ray reading of the sacroiliac (SI) joints. Because HLA-B27 typing will determine whether the AAU patients "at risk" have AS or a related arthropathy, we suggest using HLA-B27 typing in AAU patients as a diagnostic and prognostic aid. When the AAU patient is found to be HLA-B27 positive, the rheumatologist will be able to "split" these patients into those with AS and those without. Early diagnosis of AS in AAU patients is important as an early start of drug therapy and physiotherapy may prevent deformities and improve final rheumatologic outcome.

Back Pain↗
PubMed1986

IgG and IgA immune response against klebsiella in HLA-B27-associated anterior uveitis.

Enteric infections with Gram-negative bacteria are thought to play an important part in HLA-B27-associated disease such as Reiter's syndrome and reactive arthritis. But the role of bacterial infections in HLA-B27-positive ankylosing spondylitis (AS) and acute anterior uveitis (AU) is still controversial. A special interest has recently been devoted to the role of klebsiella infection in HLA-B27-associated disease. We studied the humoral immune response against a 'cross-reactive' strain of Klebsiella pneumoniae in 62 patients with anterior uveitis and 33 healthy controls. The anterior uveitis patients were subdivided into 25 HLA-B27-negative patients without AS (B27- AU+ AS-), 17 HLA-B27-positive patients without ankylosing spondylitis (B27+ AU+ AS-), and 19 HLA-B27-positive patients with ankylosing spondylitis (B27+ AU+ AS+). Total serum IgA was higher in patients than in controls in both the B27+ AU+ AS+ and B27+ AU+ AS- patients but not in the B27- AU+ AS- group. No abnormalities were observed in the total serum IgG levels. The level of both the IgG and IgA klebsiella antibodies did not differ in the various patient groups tested as compared with the controls. Comparisons between the patient groups showed that the IgG anti-klebsiella response was higher in B27-positive patients patients without AS than in those with AS. These results suggest that stimulation of mucosal surfaces may play a role in HLA-B27-associated anterior uveitis. Whether klebsiella organisms are involved in this stimulation remains unclear.

Adult↗
PubMed1986

Serology in ocular toxoplasmosis.

The diagnostic value of toxoplasma serology in ocular disease was evaluated in the following groups of patients: (I) uveitis cases of various causes (n = 291); (II) consecutive posterior and panuveitis patients (n = 60); (III) patients with definite congenital and ocular toxoplasmosis (n = 8); (IV) cases of clinical ocular toxoplasmosis (n = 25); and control patients with uveitis of non-toxoplasma origin (n = 12). No relation was observed between the level of the dye test titres and the diagnosis of ocular toxoplasmosis (groups I and II). During the active stages of the disease no typical change of the titres occurred in several longitudinally studied patients with toxoplasmosis. In group III one case was discovered to be negative by the dye test despite active ocular disease; however, IgG antibodies against toxoplasma were detected by the ELISA technique. In group IV, which was investigated by the ELISA technique, 100% of the toxoplasmosis patients were positive for IgG versus 58% of the control patients. Circulating immune complexes containing IgG and toxoplasma antigen were detected in seven of 25 toxoplasmosis patients (28%) and in two of 12 control patients (16%). Our study shows that the definite diagnosis of ocular toxoplasmosis or its exclusion by serological means only is not yet feasible. The possible superiority of the ELISA test to the dye test warrants further investigation.

Adolescent↗
PubMed1986

Quantitative determination of S-antigen in human ocular tissues, aqueous humour and serum.

Retinal S-antigen is thought to play an important role in the immunopathogenesis of uveitis. To investigate whether S-antigen is a sequestered antigen confined to the retina, a sensitive ELISA was developed to determine the levels of this protein in various human ocular tissues, aqueous humour and serum. The ELISA was performed by incubating S-antigen-containing samples with solid-phase bound immunospecific rabbit anti human S-antigen F(ab')2 fragments and then incubating the bound S-antigen with mouse anti bovine S-antigen serum and the bound mouse antibodies with peroxidase-labelled rabbit anti mouse IgG; the peroxidase activity is developed with ABTS. This method was demonstrated to be highly sensitive and specific: S-antigen could be measured at concentrations of 5-10 nanograms per ml, irrespective of whether it was present in buffer, undiluted whole serum of tissue extracts. Human retinas were shown to contain approximately 1.2 mg immunoreactive S-antigen per retina. Of the other human ocular tissues, only the vitreous and choroid (including pigment epithelium) contained small amounts of S-antigen. Low levels of S-antigen could also be detected in the aqueous humour of two out of seven patients with posterior uveitis. No immunoreactive S-antigen could be detected in the serum of either healthy individuals or patients with uveitis. Sera collected from diabetic patients 15 minutes after extensive laser photocoagulation also did not contain immunoreactive S-antigen. Preliminary experiments with rats to study the clearance of intravenously injected S-antigen from the circulation indicated that the relatively short half-life (+/- 30 min) of circulating S-antigen might account for the absence of detectable S-antigen in the patient sera.

Animals↗
PubMed1986

Autoimmunity against corneal antigens. I. Isolation of a soluble 54 Kd corneal epithelium antigen.

Corneal epithelium antibodies were detected in patients with corneal melting disease and uveitis using an immunofluorescence technique with cryostat sections of corneas obtained from various species (man, guinea pig, rabbit, mouse, rat, cow, pig). No differences in results were found using these various substrates, indicating that the autoimmune response is directed against common non-species specific corneal epithelium antigens. The serum of a patient with corneal melting disease, containing a high antibody titer against corneal epithelium was used to identify and isolate one of the bovine corneal antigens. A 54,000 dalton protein was isolated, which was shown to be the major protein present in the corneal epithelium. Absorption studies with other tissues taken from human eyes showed that cornea epithelium, cornea devoid of epithelium, ciliary body and retina contained material which cross-reacted with the isolated bovine corneal epithelium antigen, whereas iris and sclera showed no detectable cross-reaction. The incidence of autoantibodies directed against this antigen was investigated in patients with corneal melting disease, corneal transplantion and in uveitis patients using an ELISA and comparing the results with those obtained with the immunofluorescence assay on rabbit cornea sections. A positive ELISA was always associated with a positive immunofluorescence test. The presence of antibodies against the 54 Kd antigen as detected by the ELISA could be confirmed by immunoblotting in 7 out of 9 positive sera tested. A large number of sera showed a positive immunofluorescence test but a negative ELISA against the 54 Kd corneal epithelium antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

Circulating antibodies to corneal epithelium in patients with uveitis.

We investigated the incidence of circulating corneal epithelium antibodies in patients with uveitis. A high percentage of the patients (42%) were positive, whereas only 4% of controls had these antibodies in their serum. Significantly more patients with anterior and diffuse uveitis had corneal epithelium antibodies than did those with posterior uveitis. Subdivision of anterior uveitis into HLA-B27 positive versus negative patients showed a higher incidence of the antibodies in the HLA-B27 positive group. A previous history of uveitis may play a role in the pathogenesis of peripheral corneal thinning diseases, for which an autoimmune aetiology has been suggested.

Adult↗
PubMed1985

The expression of HLA-antigens in the human anterior uvea.

The expression of MHC Class I and Class II antigens was investigated in the human uvea using monoclonal antibodies in an indirect immunofluorescence technique. The anterior border layer of the iris, the non-pigmented and pigmented epithelium of the ciliary body, the external basement membrane of the ciliary body and the vascular endothelium in the uvea showed a positive staining for Class I antigens. The endothelium lining the bloodvessels in the uvea expressed the highest density of Class I antigens. Class II antigens were found only on single cells spread throughout the entire uvea. These cells did not seem to relate to any anatomical entity. No staining for Class II antigens was detected in the uveal blood vessel endothelium. The expression of HLA-antigens in the uvea may provide insight in the pathogenesis of certain HLA associated uveitis entities.

Adolescent↗
PubMed1985

Human tears inhibit the coating of proteins to solid phase surfaces.

The presence of surfactants in human tear samples was studied using methods employed in ELISA technology. Initial experiments whereby diluted tear samples were incubated with special polyacrylate ELISA microcuvettes showed no binding of tear-lactoferrin to the cuvettes whereas a marked binding of purified lactoferrin could be observed. In subsequent experiments it was shown that incubation of purified lactoferrin with increasing amounts of human tears resulted in a dose dependent inhibition of the binding of lactoferrin to the microcuvettes. Partial characterisation of the "coating inhibitory activity" in human tears was investigated by studying the effect of tears or isolated tear fractions on the non-specific binding of a peroxidase conjugated antibody onto the microcuvettes. Preincubation of microcuvettes with tears followed by a wash with phosphate buffered saline resulted in a marked inhibition of the adhesion of the peroxidase conjugate, suggesting that the coating inhibitory activity is caused by a binding of a factor in human tears to the solid phase. The findings reported here resemble earlier observations concerning lacrimal surfactants. The method described in this paper can be performed using a small quantity of human tears or isolated tear proteins and is therefore quite suitable for further biochemical analysis of tear surfactant activity as well as for clinical studies in patients with various tear film disorders.

Animals↗