AIRE Gene Mutation Presenting at Age 2 Years With Autoimmune Retinopathy and Steroid-Responsive Acute Liver Failure: A Case Report and Literature Review

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare monogenic autosomal recessive disorder caused by mutation in the autoimmune regulator (AIRE) gene. Patients usually are diagnosed at ages between 5 and 15 years when they show 3 or more manifestations, most typically mucocutaneous candidiasis, Addison's disease, and hypoparathyroidism. APECED-associated hepatitis (APAH) develops in only 10% to 40% of patients, with severity varying from subclinical chronic active hepatitis to potentially fatal acute liver failure (ALF). Ocular abnormalities are fairly common, most often keratopathy but sometimes retinopathy. Here we report a 2-year-old Japanese girl with an AIRE gene mutation who developed APAH with ALF, preceded by autoimmune retinopathy associated with anti-recoverin antibody before major symptoms suggested a diagnosis of APECED. Intravenous pulse methylprednisolone therapy followed by a corticosteroid combined with azathioprine treatment resolved ALF and achieved control of APAH. To our knowledge, our patient is the youngest reported to have ALF resulting from an AIRE gene mutation. Pulse methylprednisolone induction therapy followed by treatment with corticosteroid plus azathioprine may well be effective in other children with APAH and AIRE gene mutations.

Autoimmune retinopathy with positive anti-recoverin antibodies not associated with neoplasms: Case report

The case is presented of a non-paraneoplastic autoimmune retinopathy (AIR) with positive anti-recoverin autoantibodies. A 28-year-old woman presented with a rapidly progressive bilateral visual loss of 8 months onset. Funduscopic examination revealed diffuse fine mottled atrophic changes in both eyes. Fluorescein angiographic studies showed a pattern of mottled areas of early hyperfluorescence without leakage of dye. In the ocular coherence tomography it was observed that was a loss of external layers. The electroretinogram showed absence of rod and cone responses in the right eye, and diminished cone response associated to absence of rod response in the left eye. AIR was suspected, and empirical corticosteroid treatment was started while waiting for Western-blot results, which was finally positive for recoverin, GAPDH, anti-alpha-enolase, and aldolase. The patient was able to be treated, and her visual acuity remained stable, but as soon as it was suspended, vision was completely lost in the right eye and reduced to hand movement in the left eye.

Clinical Features of Japanese Patients With Anti-α-enolase Antibody-Positive Autoimmune Retinopathy: Novel Subtype of Multiple Drusen

PURPOSE

To evaluate clinical features of Japanese patients with anti-α-enolase antibody-positive autoimmune retinopathy (anti-enolase AIR).

DESIGN

Multicenter retrospective observational case series.

METHODS

Forty-nine eyes of 25 Japanese anti-enolase AIR patients (16 female and 9 male; mean age at first visit, 60.8 years) were included. Fundus characteristics, perimetry, spectral-domain optical coherence tomography (SD-OCT), electroretinography (ERG), best-corrected visual acuity (BCVA), and complicating systemic tumors were assessed. Protein localization of α-enolase was examined by immunohistochemistry in an enucleated eye of 1 patient.

RESULTS

Patients were classified into 3 groups: multiple drusen (48%), retinal degeneration (36%), and normal fundus (16%). Drusen varied in size from small deposits to vitelliform-like lesions. Images on SD-OCT revealed dome-shaped hyperreflectivity beneath the retinal pigment epithelium (RPE), corresponding to drusen. Perimetry showed that ring scotoma was the most frequent (39%). Rod-system and/or single-flash cone responses revealed decreased responses in 81% of the eyes. Combined rod and cone system responses demonstrated significantly lower a-wave amplitudes in the degeneration group than in the drusen group (P = .005). BCVA was improved or maintained in 80% of the eyes during follow-up. Malignant or benign tumors were detected in 30% of patients. The RPE and photoreceptor layers were immunopositive for α-enolase.

CONCLUSIONS

The drusen subtype, scarcely described in the literature, is suggested to characterize Japanese patients with anti-enolase AIR. The different funduscopic features with different functional severities may have resulted from antibody-mediated damage to RPE as well as photoreceptor cells.

Supraphysiologic control over HIV-1 replication mediated by CD8 T cells expressing a re-engineered CD4-based chimeric antigen receptor

HIV is adept at avoiding naturally generated T cell responses; therefore, there is a need to develop HIV-specific T cells with greater potency for use in HIV cure strategies. Starting with a CD4-based chimeric antigen receptor (CAR) that was previously used without toxicity in clinical trials, we optimized the vector backbone, promoter, HIV targeting moiety, and transmembrane and signaling domains to determine which components augmented the ability of T cells to control HIV replication. This re-engineered CAR was at least 50-fold more potent in vitro at controlling HIV replication than the original CD4 CAR, or a TCR-based approach, and substantially better than broadly neutralizing antibody-based CARs. A humanized mouse model of HIV infection demonstrated that T cells expressing optimized CARs were superior at expanding in response to antigen, protecting CD4 T cells from infection, and reducing viral loads compared to T cells expressing the original, clinical trial CAR. Moreover, in a humanized mouse model of HIV treatment, CD4 CAR T cells containing the 4-1BB costimulatory domain controlled HIV spread after ART removal better than analogous CAR T cells containing the CD28 costimulatory domain. Together, these data indicate that potent HIV-specific T cells can be generated using improved CAR design and that CAR T cells could be important components of an HIV cure strategy.

Expression of a Chimeric Antigen Receptor in Multiple Leukocyte Lineages in Transgenic Mice

Genetically modified CD8+ T lymphocytes have shown significant anti-tumor effects in the adoptive immunotherapy of cancer, with recent studies highlighting a potential role for a combination of other immune subsets to enhance these results. However, limitations in present genetic modification techniques impose difficulties in our ability to fully explore the potential of various T cell subsets and assess the potential of other leukocytes armed with chimeric antigen receptors (CARs). To address this issue, we generated a transgenic mouse model using a pan-hematopoietic promoter (vav) to drive the expression of a CAR specific for a tumor antigen. Here we present a characterization of the immune cell compartment in two unique vav-CAR transgenic mice models, Founder 9 (F9) and Founder 38 (F38). We demonstrate the vav promoter is indeed capable of driving the expression of a CAR in cells from both myeloid and lymphoid lineage, however the highest level of expression was observed in T lymphocytes from F38 mice. Lymphoid organs in vav-CAR mice were smaller and had reduced cell numbers compared to the wild type (WT) controls. Furthermore, the immune composition of F9 mice differed greatly with a significant reduction in lymphocytes found in the thymus, lymph node and spleen of these mice. To gain insight into the altered immune phenotype of F9 mice, we determined the chromosomal integration site of the transgene in both mouse strains using whole genome sequencing (WGS). We demonstrated that compared to the 7 copies found in F38 mice, F9 mice harbored almost 270 copies. These novel vav-CAR models provide a ready source of CAR expressing myeloid and lymphoid cells and will aid in facilitating future experiments to delineate the role for other leukocytes for adoptive immunotherapy against cancer.

[Severe visual loss caused by autoimmune retinopathy]

BACKGROUND

Autoimmune retinopathy (AIR) is a rare disorder which may present as a paraneoplastic syndrome. AIR is associated with the presence of anti-retinal antibodies. These antibodies are assumed to cause damage to the retina, resulting in progressive vision loss.

CASE DESCRIPTION

A 74-year-old man visited the ophthalmologist with a serious, progressive loss of vision, without any noteworthy abnormalities at routine ophthalmological examination. The electroretinogram was characteristic of loss of photoreceptor function. Anti-retinal antibodies against recoverin were detected in serum. After referral to an internist on account of a suspected diagnosis of paraneoplastic AIR, the patient was diagnosed with a lung carcinoma, confirming the diagnosis of cancer-associated paraneoplastic AIR.

CONCLUSION

An unexplained loss of vision is highly suggestive of paraneoplastic AIR, even in patients without a known malignancy. Laboratory techniques for the detection of the anti-retinal antibody against recoverin have recently been implemented in the Netherlands, facilitating the diagnosis of AIR.

[Paraneoplastic retinopathy and optic neuropathy]

Paraneoplastic retinopathy including cancer-associated retinopathy (CAR) and melanoma-associated retinopathy (MAR), and paraneoplastic optic neuropathy (PON) are visual disorders associated with systemic cancer. Patients with CAR typically present with progressive loss of vision and photopsia, which are related to dysfunction of both cones and rods in photoreceptors. The triad of photosensitivity, ring scotoma, and a reduced caliber of the retinal arteriole along with undetectable signals in electroretinogram (ERG) are specific manifestations of CAR. CAR is associated most commonly with small-cell lung cancer (SCLC) and occasionally with gynecologic tumors, and it is usually caused by autoantibodies against recovering, which is a calcium-binding photoreceptor protein that participates in the transduction of light. MAR is characterized by shimmering, flickering, or pulsating photopsias, and usually occurs in the patients with a cutaneous melanoma. MAR differs from CAR in terms of visual acuity and color vision and is associated with a characteristic pattern detected in ERG. Autoantibodies against the bipolar cells of the retina have been identified in patients with MAR. Patients with PON frequently present with progressive visual loss and optic disc edema, or with other paneoplastic neurologic syndromes related to SCLC, such as paraneoplastic encephalomyelitis or retinitis, ophthalmoplegia, and subacute cerebellar syndrome. Autoantibodies against collapsin-responsive mediator protein-5 (CRMP-5, also called anti-CV2) are considered to be as the causative factor. Treatments with corticosteroids, plasma exchange, and intravenous immune globulin as well as treatment of the tumor itself, occasionally improves these paraneoplastic visual syndromes. However, the prognosis depends on their underlying malignancy.

Cone Dysfunction as a Paraneoplastic Syndrome Associated with Retinal Antigens Approximating 40 kiloDalton

Reports on cancer-associated retinopathies (CAR) have increased in recent years as the autoimmune reactions responsible have become better understood. The 23-kDalton autoantigen 'recoverin' was the first retinal antigen implicated in CAR, but others have since been described. We report an additional case involving an autoantigen other than recoverin, with five-year follow-up of a 50-year-old woman suffering from the CAR syndrome, with ocular abnormalities restricted to cone dysfunction. The patient had a history of laryngeal carcinoma surgically removed 18 months prior to presenting to the ophthalmologist with photophobia and decreased vision in both eyes. The patient's abnormal retinal hypersensitivity included antibody activity with two retinal antigens approximating 40 kD, located within the outer segments of the photoreceptor layer. To our knowledge, this is the first description of a cancer-associated, cone-specific dystrophy involving an abnormal amount of immunologic activity with two retinal proteins approximating 40 kD, that may prove to be isoforms of the same antigen.

[Cancer associated retinopathy (CAR). Two clinical cases and review of the literature]

The cancer associated retinopathy (CAR) is a paraneoplasic retinopathy in which an antigen-antibody reaction, due to retinal antigens, also expressed in tumours, leads to degeneration of retinal photoreceptor cells. We observed in CHL-Luxembourg, 2 clinical cases of non-Hodgkin's lymphoma with severe prognosis in whom we described the presence of anti-recoverin antibodies. The CAR is most frequently associated with small cell lung and ovarian carcinomas. Clinical symptoms (phosphenes, progressive loss of eyesight) sometimes, occur before the diagnostics of primary cancer. Retinal degeneration may be assessed by electroretinogram, visual field, fundus oculi. A crossed reactivity between tumour and retinal antigens may initiate an antigen-antibody reaction, that implicates optic lesions. Different antigenic proteins have been evidenced, the most frequent being the recoverin. This protein plays a role in the adaptation to light and darkness. It is expressed in more than 50% of different types of neoplastic cells and would play a role in tumour proliferation. The antigen-antibody reaction leads to death by apoptosis of photoreceptor and bipolar retinal cells. These antirecoverin antibodies are also observed in other retinal degenerative diseases. The diagnosis is confirmed by titration of antibodies in the serum by Western Blot, Elisa and immunohistochemical methods. However, this diagnosis is by exclusion (vs. brain metastasis, drug toxicity, demyelinating diseases, autoimmune non paraneoplastic retinopathies). Corticosteroids are the only therapy that can bring some benefit. There is no value in starting a therapy if the retinal degeneration has reached an advanced stage. Note that the CAR must be distinguished from the Melanoma Associated Retinopathy (MAR) which is a similar paraneoplastic syndrome, but with rapid evolution of its symptoms and different etio-pathogenesis.

Identification of MHC class I H-2 Kb/Db-restricted immunogenic peptides derived from retinal proteins

PURPOSE

To identify H-2 Kb/Db-binding immunogenic peptides derived from retinal proteins.

METHODS

Computer-based prediction was used to identify potentially H-2 Kb/Db-binding peptides derived from the interphotoreceptor retinol-binding protein (IRBP), soluble retinal antigen (S-antigen), recoverin, phosducin, and pigment epithelium-derived factor (PEDF). The affinity of the peptides was analyzed by their abilities to upregulate the expression of major histocompatibility complex (MHC) class I on TAP-deficient cells (RMA-S cells) with flow cytometry. C57BL/6 mice were immunized subcutaneously, with individual peptides in incomplete Freund's adjuvant (IFA). Eight days after immunization, splenocytes were isolated for cytotoxic T-lymphocyte (CTL) analysis. A 51chromium-release assay was used to detect specific CTL reactivity generated in the cultures. Eyes were enucleated for histopathological analysis on day 21 after immunization with IRBP or IRBP and the immunogenic peptides.

RESULTS

All the 21 predicted peptides were found to upregulate expression of H-2 Kb/Db on RMA-S cells. Five peptides, the two IRBP-derived peptides IRBP89-96 and IRBP(101-108), and the three PEDF-derived peptides, PEDF389-397, PEDF139-147, and PEDF272-279, induced specific CTL responses in vivo, whereas the remaining 16 peptides, including 5 IRBP-derived peptides, 5 S-antigen-derived peptides, 1 recoverin-derived peptide, 1 phosducin-derived peptide, and 4 PEDF-derived peptides, did not induce specific CTL reactivity. The immunogenic peptides alone did not induce inflammation in the eyes, but they could enhance severity of uveitis induced by IRBP.

CONCLUSIONS

Five of 21 H-2 Kb/Db-binding retinal protein-derived peptides were found to be immunogenic, suggesting that these peptides could function as autoantigenic epitopes in the development of inflammatory eye diseases, such as uveitis.

Effects of cytotoxic T lymphocyte antigen 4 (CTLA4) signaling and locally applied steroid on retinal dysfunction by recoverin, cancer-associated retinopathy antigen

PURPOSE

To assess the cytotoxic T lymphocyte antigen 4 (CTLA4) pathway in the recoverin peptide (R64; AYAQHVFRSF) mouse model of cancer-associated retinopathy (CAR) and to assess the protective effects of subconjunctival triamcinalone injections in this model.

METHODS

To study the role of the CTLA4 pathway on the R64-induced mouse model of CAR, BALB/c mice were immunized with R64. The mice were further intraperitoneally treated with anti-CTLA4 antibody to get stronger immunoreaction. The development of CAR was evaluated by electroretinogram (ERG) examinations 21 days after treatment. A cytotoxicity assay was employed to detect induction of R64-specific cytotoxic T lymphocytes (CTLs). Immunoblotting to assess the development of anti-recoverin antibody and a T cell proliferation assay to determine the activity of lymphocytes against R64 were examined in two experimental groups, anti-CTLA4 antibody treated and untreated mice.To study the protective effect of subconjunctival triamcinalone in this model, mice immunized with R64 peptide and anti-CTLA4 antibody were either treated with 50 mg/kg/body weight of triamcinalone or phosphate buffered saline (PBS). These mice were assayed using ERG and histological examination 35 days after the first R64 immunization.

RESULTS

When mice were challenged with R64 peptide and anti-CTLA4 antibody, R64 peptide-specific CTLs were induced and decreased b-wave amplitudes were observed in ERG. Conversely, no CAR symptoms were detected in mice not treated with anti-CTLA4 antibody. Anti-CTLA4 antibody treatment did not give any significant differences in T cell proliferation and humoral reaction against recoverin. Subconjunctival triamcinalone treated mice show a trend toward improved survival of outer nuclear layer cell bodies, but did not show significant improvement of ERG amplitudes compared to the untreated mice.

CONCLUSIONS

Inhibition of the CTLA4 pathway is essential for the development of recoverin-induced murine CAR, suggesting that strengthening negative T cell signaling through CTLA4 may lessen the retinal degenerations in CAR-affected subjects. The positive effects of attenuation of the CTLA4 pathway must be weighed against a potential negative effect on survival since this pathway may also provide natural immunotherapy against the underlying malignancy. Subconjunctival injections of triamcinalone may have beneficial effects on the integrity of the outer nuclear layer (ONL) of the retina in the CAR model, although there was no significant effect on the ERG recordings.

Anti-recoverin antibodies induce an increase in intracellular calcium, leading to apoptosis in retinal cells

Autoantibodies against recoverin, a Ca2+-binding protein found in patients with cancer-associated retinopathy (CAR syndrome), penetrate retinal cells and induce their apoptosis via a mitochondrial pathway. The goal of this study was to investigate whether the entry of anti-recoverin antibody into E1A.NR3 retinal cells causes a change in intracellular Ca2+. Intracellular Ca2+ was measured using the Ca2+-sensitive fluorescent dye Fura-2 AM in living E1A.NR3 retinal cells treated with anti-recoverin antibody Rec-1, patients' autoantibodies, and control rat and human IgG. The exposure of retinal cells to Rec-1 antibody and to the CAR patients' autoantibodies in vitro caused a significant increase in intracellular Ca2+, while non-specific antibodies did not induce such an effect. Co-treatment of the E1A.NR3 cells with Rec-1 in the presence of nifedipine, a L-type Ca2+ channel blocker, significantly suppressed the increase of Ca2+. Treatment with nifedipine also blocked changes in the anti-apoptotic protein bcl-xL and in expressions of the pro-apoptotic protein bax. Nifedipine-treated cells also showed a decrease in cytosolic cytochrome c release and a decrease in caspase 3 activation, compared to cells treated only with Rec-1 antibody. The increase in the antibody-induced Ca2+ is at least in part dependent on extracellular Ca2+. Nifedipine was found to inhibit the entry of Ca2+ into the cells and to protect them from Rec-1-induced apoptosis. Increased levels of intracellular Ca2+ may lead to retinal dysfunction and degeneration in the CAR syndrome. Our results provide a molecular basis for the use of Ca2+ blockers in the treatment of the CAR syndrome.

Bilateral diffuse uveal melanocytic proliferation in a patient with cancer-associated retinopathy

PURPOSE

To describe a patient with bilateral diffuse uveal melanocytic proliferation (BDUMP) and cancer-associated retinopathy (CAR).

DESIGN

Interventional case report.

METHODS

A 66-year-old woman developed progressive vision loss 4 months after total hysterectomy. Ophthalmologic examination, Western blot test of sera and aqueous humor, and immunohistochemistry of carcinoma cells were performed.

RESULTS

Testing revealed BDUMP and severe retinal dysfunction. Autoantibodies against recoverin and heat shock cognate protein 70 (hsc 70) were detected in serum. Cytoplasmic immunoreactivity for recoverin and hsc 70 was observed in endometrioid carcinoma cells.

CONCLUSIONS

Simultaneous cases of BDUMP and CAR are rare. Aberrantly expressed recoverin and hsc 70 triggered serum autoantibody production, which caused photoreceptor degeneration.