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Biomedical subjects

L Luyendijk

Publications and source records attributed to L Luyendijk.

29 records · Page 2Linked to original sources
PubMed1990

Aqueous humour analysis in Fuchs' heterochromic cyclitis.

Aqueous humor from 23 patients with Fuchs' heterochromic cyclitis (FHC) was analysed by a number of immunological methods. Intraocular IgG synthesis was found in 65% of patients and oligoclonal IgG bands, mainly of the IgG1 subclass, identified in 57%. There was a relative increase in IgG1 (P less than 0.01) as compared to patients with senile cataract. Local production of the cytokine Interleukin-6 was demonstrated in 63% of patients (P less than 0.01). Analysis of aqueous by HPLC and SDS-PAGE failed to reveal any abnormalities specific for FHC. These findings add further evidence to the theory of immune dysregulation in this condition.

Adult↗
PubMed1990

Analysis of aqueous humor immunoglobulin G in uveitis by enzyme-linked immunosorbent assay, isoelectric focusing, and immunoblotting.

Immunoglobulin G (IgG) in aqueous humor from patients with various uveitis syndromes was analyzed using a number of immunologic techniques. Sixty-five percent of patients with Fuchs' heterochromic cyclitis (FHC), 70% of patients with other forms of uveitis, and 44% of controls showed local synthesis of IgG, as demonstrated by an elevated IgG:albumin relative concentration ratio. Using an enzyme-linked immunosorbent assay to measure the concentration of IgG subclasses 1-4, a relative excess of IgG1 was found in the aqueous compared with the serum in FHC. Isoelectric focusing and immunoblotting studies revealed oligoclonal IgG bands in the aqueous of 13 of 23 (57%) patients with FHC, most being of the IgG1 subclass. Oligoclonal bands were not found in 18 patients with other types of uveitis or 13 patients undergoing surgery for senile cataract. These findings indicate intraocular production of IgG of restricted specificity in FHC, providing further evidence for local immune dysfunction in this condition. As yet the antigenic stimulus for this oligoclonal B-cell response has not been identified.

Adult↗
PubMed1989

HPLC analysis of tear proteins in giant papillary conjunctivitis.

Giant papillary conjunctivitis (GPC) is a well defined entity seen in patients with deposits on their lenses. High performance liquid chromatography (HPLC) tear protein analysis was performed on 17 GPC patients and compared with healthy controls with and without contact lenses. The IgA levels are somewhat lower in GPC patients as compared with healthy controls not wearing lenses (P less than 0.05). A similar decrease was also seen in the control group wearing contact lenses. We were not able to identify a specific HPLC tear protein profile in GPC patients as compared with controls. The HPLC profile therefore gives no explanation for the lens deposits and is not suitable as a diagnostic or prognostic tool.

Adult↗
PubMed1989

Aqueous humor analysis as a diagnostic tool in toxoplasma uveitis.

Analysis of local toxoplasma antibody production to confirm a suspected clinical diagnosis of toxoplasma chorioretinitis is a valuable diagnostic tool. Determination of toxoplasma antibodies in the blood of the patient is of limited use. When blood toxoplasma tests are negative this indicates that toxoplasma as a causative organisms in the pathogenesis of uveitis is unlikely. A positive blood test is a sensitive test (100% patients positive) but not a specific test since so many healthy individuals already have undergone subclinical infection and have acquired humoral immunity against the parasite. We analysed 93 paired aqueous and serum samples for toxoplasma antibodies and total IgG and determined the Goldmann-Wittmer coefficient. In patients retrospectively diagnosed as having toxoplasma chorioretinitis 16 out of 22 had a positive coefficient, indicating local parasite antibody production. In one patient with AIDS we also found a positive toxoplasma coefficient. Three out of 15 patients with posterior uveitis of unknown origin also had a positive coefficient. None of the cataract patients tested (n = 32) had a positive coefficient. Major drawbacks of aqueous humor analysis are that a false negative antibody coefficient can occur when a massive blood aqueous barrier breakdown has occurred.

Antibodies, Protozoan↗
PubMed1988

Factors influencing the quantitative determination of tear proteins by high performance liquid chromatography.

HPLC analysis of human tears allows tear protein profiles to be obtained within ten minutes. A tear protein profile normally consists of 4 major peaks: IgA, lactoferrin, protein G and lysozyme. Although it is a rapid method, the use of High Performance Liquid Chromatography in the (quantitative) determination of proteins in tears is influenced by various factors. The day to day variability of the quantitative use, ranges between 7 and 9% for the various tear proteins. Combining the HPLC method with a convenient collection method such as sponges or Schirmer strips, showed that the sponges and some of the Schirmer strips used in this study eluted significant material absorbing light at 280 nm. No statistical difference was observed in the HPLC protein profiles of tears collected with Schirmer strips or with sponges. Using sponges has the advantage that they can absorb almost twice as much tears in a same period of time as Schirmer strips. HPLC analysis of human tear proteins is not accurate when there is albumin leakage as in traumatic sampling with Schirmer strips or in inflammatory states. The I-125 column which was used in our study is not able to separate lactoferrin and albumin, which may cause an overestimation of lactoferrin in inflammatory conditions. The study presented here indicates that for quantitative use of HPLC in epidemiological tear protein research better separating protein gel filtration columns are needed.

Adult↗
PubMed1987

Genes on chromosome 14q and their role in the pathogenesis of HLA-B27 associated diseases.

Genetic factors other than HLA-B27 may play a role in the pathogenesis of ankylosing spondylitis (AS), acute anterior uveitis (AAU) and Reiter's syndrome (RS). Studies by Brewerton et al. and Kijlstra et al. showed associations between the MZ phenotype of alpha 1-antitrypsin and the Gm phenotype zafngb of IgG in patients with AAU, who developed AS. The loci for alpha 1-antitrypsin (PI) and Gm allotypes (IGH) are situated on the tip of the long arm of chromosome 14. In the present study we tried to clarify and extend the above studies. In 41 B27+ AAU patients with AS the alpha 1-antitrypsin and Gm phenotype and allotype frequencies were not statistically different from those in B27+ AS patients developing AAU and in B27+ AAU patients without AS, in B27+ AS patients without AAU, B27+ patients with Reiter's syndrome, B27+ patients with low back pain, B27- AAU patients and normal controls. It is therefore unlikely that genes on the tip of chromosome 14 play a role in the pathogenesis of B27 associated diseases. A hypothesis was formed suggesting that a bacterial-derived modifying factor may replace the position of beta 2 microglobulin in the HLA-B27 molecule resulting in an impaired cytotoxic T cell reactivity.

Alleles↗
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

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↗
PubMed1985

Expression of HLA-B27 antigens on mononuclear leucocytes in ankylosing spondylitis.

Differences in expression of HLA-B27 antigens on immune competent cells might play a role in the susceptibility to environmental factors which may be responsible for the initiation of ankylosing spondylitis (AS). Using a quantitative complement-mediated lymphocytotoxity assay we determined the expression of HLA-B27 antigens on the membranes of mononuclear cells obtained from 20 patients with AS, four patients with other seronegative arthropathies and eight healthy controls. The variation in expression of B27 between individuals was quite extensive, but there was no significant difference in the mean titration curves obtained for each of the three groups. These findings suggest that the expression of HLA-B27 antigens on the membrane of mononuclear leucocytes does not play a role in the pathogenesis of AS.

Antigens, Surface↗