HLA-A29-positive Birdshot Chorioretinopathy in a Hispanic Patient

Birdshot chorioretinopathy in an HLA-A29 positive Asian patient

Purpose

To present a case of birdshot chorioretinopathy (BCR) in a Chinese patient with HLA-A29 positivity.

Observations

A 45-year-old Chinese female presented at a tertiary Ophthalmology Clinic with complaints of frequent headaches as well as blurred vision, photophobia, and pressure in the left eye (OS). The patient had a significant ocular history of left orbital cavernous hemangioma status post lateral orbitotomy and resection. Uncorrected visual acuity was 20/20 in the right eye (OD) and 20/40 in OS (pinhole 20/30). Funduscopic examination demonstrated optic disc edema, left eye worse than right eye, and vascular tortuosity in both eyes (OU). Late phase fluorescein angiography (FA) showed extensive perivascular and optic disc leakage and peripheral capillary leakage in OU. Laboratory evaluations were positive for human leukocyte antigen-A29 (HLA-A29). The patient was started on 40 mg prednisone daily; mycophenolate mofetil 500 mg twice daily was subsequently added.At the 3-month consultation visit to the Uveitis Clinic, dilated funduscopic examination revealed 1+ vitreous cells and improved optic disc edema in OU. FA showed improved vascular and optic disc leakage in OS but worsened leakage in OD. At this point, indocyanine green angiography (ICGA) was ordered which revealed hypocyanescent lesions throughout the choroid that were centered on the optic disc, supporting and confirming the diagnosis of BCR.

Conclusions and Importance

The index patient is the first reported case of BCR in an HLA-A29 positive Asian patient.

Birdshot retinochoroiditis in Brazil: a multicenter review of 40 patients

Background

Birdshot retinochoroiditis (BRC) is a rare and chronic bilateral uveitis mostly found in Caucasians. As few data are available about the clinical course of BRC in Hispanic patients, we aimed to report the clinical findings and the evolution of BRC in Brazilian patients.

Methods

This retrospective cohort multicenter nationwide study was performed by analyzing the records of patients with BRC diagnoses from Brazilian ophthalmological centers from April 1995 to May 2020.

Results

Forty patients (80 eyes) with a diagnosis of BRC were evaluated. The mean age was 53 years, and there was no sex predominance. All tested patients (34/40) were positive for HLA-A29. The diagnosis of BRC was made following the Levinson et al. criteria, and all ancillary tests were performed to exclude differential diagnoses. Clinical signs and symptoms, such as complications and treatment, were described.

Conclusions

BRC evolution in Brazilian patients seems to have some peculiarities that diverge from the published literature available about Caucasians, as AS inflammation is higher in this population.

HLA-A29 and Birdshot Uveitis: Further Down the Rabbit Hole

HLA class I alleles constitute established risk factors for non-infectious uveitis and preemptive genotyping of HLA class I alleles is standard practice in the diagnostic work-up. The HLA-A29 serotype is indispensable to Birdshot Uveitis (BU) and renders this enigmatic eye condition a unique model to better understand how the antigen processing and presentation machinery contributes to non-infectious uveitis or chronic inflammatory conditions in general. This review will discuss salient points regarding the protein structure of HLA-A29 and how key amino acid positions impact the peptide binding preference and interaction with T cells. We discuss to what extent the risk genes ERAP1 and ERAP2 uniquely affect HLA-A29 and how the discovery of a HLA-A29-specific submotif may impact autoantigen discovery. We further provide a compelling argument to solve the long-standing question why BU only affects HLA-A29-positive individuals from Western-European ancestry by exploiting data from the 1000 Genomes Project. We combine novel insights from structural and immunopeptidomic studies and discuss the functional implications of genetic associations across the HLA class I antigen presentation pathway to refine the etiological basis of Birdshot Uveitis.

Electroretinogram and visual field changes in a case of birdshot chorioretinopathy

PURPOSE

This case report explores the role of the visual field perimetry and electroretinogram (ERG) in cases of non-infectious uveitis in the assessment and monitoring of retinal function and response to treatment.

METHODS

A 59-year-old Caucasian female presenting with bilateral posterior uveitis newly diagnosed as birdshot chorioretinopathy (BSCR) presenting with bilateral decrease in visual acuity and cystoid macular edema, as well as a paracentral scotoma in the right eye. The diagnosis and follow-up of the case was done using visual field perimetry, optical coherence tomography (OCT), and ERG.

RESULTS

Baseline ERG showed a marked decrease in the amplitudes of the scotopic and photopic responses and a delay of peak times mainly in the right eye. Mycophenolate mofetil at 2 g/day and oral prednisolone at 1 g/kg/day were administered with gradual tapering of the corticosteroids. After 5 months, there was a noticeable improvement in the visual acuity, macular edema in OCT, and an obvious increase in the amplitudes of the ERG associated with a decrease in peak times, particularly in the 30 Hz photopic 3.0 Flicker of the right eye.

CONCLUSION

This case report highlights the importance of the peak time and wave amplitudes of the 30 Hz photopic DA 3.0 Flicker as being a sensitive parameter in the diagnosis and follow-up of BSCR.