Immunoglobulin E in aqueous humour

The Analysis of Dynamic Changes and Prognosis of Posner-Schlossman Syndrome with Cytomegalovirus Infection and Antiviral Therapy

Purpose

To analyze how keratic precipitate (KP) morphology changes during Posner–Schlossman syndrome (PSS) prognosis and raise medication suggestions on 2% ganciclovir eye drops.

Materials and Methods

Clinical retrospective cohort study in the Eye & ENT Hospital of Fudan University, Shanghai, China. The attacked eyes of 98 eligible subjects diagnosed unilateral PSS were enrolled between 2016 and 2019. All patients were treated with intraocular pressure-lowering drugs and anti-inflammatory steroids. 2% ganciclovir eye drops were given to cytomegalovirus (CMV) immunoglobulin G (IgG) correction ratio positive patients. Frequent follow-ups and examinations were performed. KP morphology was focused and categorized into coin-shaped, mutton-fat, and pigmented. Medical histories were noted. Multidimensional analysis was given.

Results

Totally 47 patients in 98 achieved all-KP disappearance. Mean treatment time was (5.13 ± 3.66) weeks. Total KP disappearance was negatively correlated with mutton-fat and pigmented KPs at the first visit (P=0.020, P=0.007) and treatment time was also longer (P=0.018, P=0.014). Mean cumulative steroids dosage for 47 subjects was (159.66 ± 161.84) drops. CMV IgG correction ratio positive patients had smaller corneal endothelial cell density (P < 0.005) and larger cup-to-disc ratio (P=0.017) than negative subjects. Cumulative steroid treatment time was longer in the CMV-positive group, and overall dosage was also larger. However, due to 2% ganciclovir eye drops, daily steroid dosage was lower in the CMV-positive group.

Conclusions

The disappearance of mutton-fat and pigmented KPs needed longer treatment time. Paired aqueous humor and serum CMV IgG tests were recommended in PSS patients with coin-shaped KPs. 2% ganciclovir eye drops improved prognosis; and steroids dosage reduced significantly.

Evaluation of the Goldmann-Witmer coefficient in the immunological diagnosis of ocular toxocariasis

Ocular toxocariasis (OT) is a zoonotic parasitic infection mainly caused by the intraocular tissue invasion of second-stage Toxocara canis or Toxocara cati larva. Measuring specific anti-T. canis antibodies in the intraocular fluid (IF) can increase OT diagnosis accuracy using Goldmann-Witmer coefficient (GWC). However, there is no systemic evaluation of GWC application in the immunological diagnosis of OT. To assess GWC for the immunodiagnosis of ocular toxocariasis, paired IF and serum samples from 72 patients diagnosed with OT were retrospectively analyzed for specific anti-T. canis IgG by enzyme linked immunosorbent assay (ELISA). GWC values were calculated to determine intraocular specific IgG production. Clinical features and other laboratory data were recorded, and their correlations with GWC evaluated. Of the 72 OT patients, 60 (83.33%) showed intraocular specific IgG production confirmed by GWC, while intraocular nonspecific IgE production was found in 64/69 (92.75%) cases. No significant correlation was found among clinical features and IF specific IgG production. Values for peripheral blood samples were lower than those of intraocular fluid regarding OT screening, and vitreous humor samples showed increased local specific IgG and nonspecific IgE production compared with aqueous humor samples. Overall, our results indicate that GWC and intraocular IgE production have referential values in diagnosing ocular toxocariasis.

Measurement of intraocular IgA and IgM synthesis and filtration through the blood-aqueous barrier in cataract patients

The authors have tested two formulas by means of which the filtrated and the intraocularly (intrathecally) synthesized fraction of particular protein can be distinguished. The laser nephelometric method was applied to determine the serum (IgG, IgA, IgM, C3, albumin), aqueous humor (IgA, IgM, albumin) and CSF (IgG, IgM, C3, albumin) protein values in 42 subjects to test two models in physiological conditions. It was confirmed that the best results were achieved using the formula after Stambuk. Computer simulation performed to compare the formulas after Stambuk and Reiber & Felgenhauer showed a strong correlation (r greater than 0.98) between the calculated filtrated fractions of both models in a wide range of different barrier permeabilities. Laser nephelometry proved to be a useful method to determine low IgA and IgM values in aqueous humor.

Nonspecific immunoglobulin E in aqueous humor: evaluation in uveitis

The levels of immunoglobulin E (IgE) in aqueous humor (AH) and serum were determined in 74 uveitis patients and 13 control patients with senile cataract. Uveitis patients' levels ranged from less than 0.06 to 460 IU/ml according to the paper radioimmunosorbent test (PRIST; limit of sensitivity, 0.06 IU/ml). Only one control patient had an AH level higher than the sensitivity limit (0.08 IU/ml). Of the five patients with the highest levels in the AH, four had toxocaral retinitis. The ratio of AH/serum to IgE normalized to the albumin concentration was calculated in 25 uveitis patients and was greater than 0.60 in 13 cases, indicating a possible intraocular IgE synthesis.

Protein composition of human aqueous humor: SDS-PAGE analysis of surgical and post-mortem samples

We analyzed the protein composition of human aqueous humor. Samples were obtained by paracentesis from 25 human eyes (age range 64-92 years) at elective cataract surgery, and from 20 age-matched post-mortem eyes within 1.5 to 18 hr after death. Individual samples were assayed for total protein, and the polypeptides were separated by qualitative SDS-PAGE into high-, medium- and low-molecular-weight ranges and then silver-stained. The clinical samples showed a remarkable consistency in the total protein values (mean +/- SEM: 12.4 +/- 2.0 mg per 100 ml) and no detectable variations in the profiles of the silver-stained proteins. Twelve major protein fractions, with apparent molecular weights of 140, 80 (doublet), 67, 60 (doublet), 35, 27, 25, 17, 14.6 and 9 kDa, were present. A preliminary analysis showed that the 17 kDa band contained a molecule resembling basic fibroblast growth factor. Two additional samples of aqueous humor from patients whose blood/aqueous barrier was compromised during paracentesis showed a quantitative and qualitative increase in the polypeptides that were present. Compared with the samples of aqueous humor obtained at surgery, the post-mortem samples exhibited a greater variability in total protein content (56.1 +/- 11.6 mg per 100 ml) and an increased number of high- and low-molecular-weight protein fractions. In view of wide differences in the clinical parameters, including ocular and systemic medications, systemic illness, surgical premedications, anesthesia and total serum protein values, the similarity in the protein profiles of the carefully drawn surgical samples is most remarkable. Our results indicate that, in patients who underwent elective cataract surgery, the levels of major proteins in human aqueous humor are not affected by wide individual variations in the clinical parameters. We attribute this finding to the care taken in the collection of aqueous humor samples.