Isolated lacrimal gland enlargement as a presenting sign of relapse of B-cell acute lymphoblastic leukemia in an adult.

A 25-year-old woman with a history of acute lymphoblastic leukemia with Philadelphia chromosome (BCR 22q11.2-ABL1 (9q34)) presented with progressively worsening swelling and pain in her left upper eyelid of 3 months' duration. Magnetic resonance imaging showed a heterogeneously enhancing mass lesion in the left lacrimal gland. An incisional biopsy was performed; histopathology showed atypical lymphocytic cells, and flow cytometry revealed a similar immunophenotype to her previously diagnosed cancer. Her presentation was consistent with recurrence of acute lymphoblastic leukemia in the lacrimal gland, which can rarely be involved in relapse of acute lymphoblastic leukemia.

CRISPR Systems Suitable for Single AAV Vector Delivery.

CRISPR (clustered regularly interspaced short palindromic repeats)/Cas gene editing is a revolutionary technology that can enable the correction of genetic mutations in vivo, providing great promise as a therapeutic intervention for inherited diseases. Adeno-associated viral (AAV) vectors are a potential vehicle for delivering CRISPR/Cas. However, they are restricted by their limited packaging capacity. Identifying smaller Cas orthologs that can be packaged, along with the required guide RNA elements, into a single AAV would be an important optimization for CRISPR/- Cas gene editing. Expanding the options of Cas proteins that can be delivered by a single AAV not only increases translational application but also expands the genetic sites that can be targeted for editing. This review considers the benefits and current scope of small Cas protein orthologs that are suitable for gene editing approaches using single AAV vector delivery.

Promoter Orientation within an AAV-CRISPR Vector Affects Cas9 Expression and Gene Editing Efficiency.

Adeno-associated virus (AAV) vectors have been widely adopted for delivery of CRISPR-Cas components, especially for therapeutic gene editing. For a single vector system, both the Cas9 and guide RNA (gRNA) are encoded within a single transgene, usually from separate promoters. Careful design of this bi-cistronic construct is required due to the minimal packaging capacity of AAV. We investigated how placement of the U6 promoter expressing the gRNA on the reverse strand to SaCas9 driven by a cytomegalovirus promoter affected gene editing rates compared to placement on the forward strand. We show that orientation in the reverse direction reduces editing rates from an AAV vector due to reduced transcription of both SaCas9 and guide RNA. This effect was observed only following AAV transduction; it was not seen following plasmid transfection. These results have implications for the design of AAV-CRISPR vectors, and suggest that results from optimizing plasmid transgenes may not translate when delivered via AAV.

A distinct retinal pigment epithelial cell autofluorescence pattern in choroideremia predicts early involvement of overlying photoreceptors.

PURPOSE: Choroideremia is an X-linked retinal disease characterized by early retinal pigment epithelium (RPE) loss and subsequent retinal degeneration. The RPE adopts either a smooth or mottled appearance on fundus autofluorescence (FAF). It is not known how RPE changes predict the health of the overlying ellipsoid zone (EZ). METHODS: A retrospective review of FAF and optical coherence tomography (OCT) images from 20 patients with choroideremia was performed. The percentage of intact EZ in each smooth and mottled FAF region was determined using one horizontal trans-foveal OCT section. RESULTS: Fourteen out of 20 patients had distinct smooth and mottled areas in both eyes and were included in the sub-analysis. On average, 62.5 ± 10.1% of the EZ in each smooth region of the right eyes was intact compared to 10.0 ± 4.3% in the mottled areas. The same trend was observed in left eyes: 76.5 ± 7.2% of the EZ was intact in the smooth regions versus 9.8 ± 3.9% in the mottled areas (two-way anova, p < 0.0001). Thus, the mottled FAF regions were associated with EZ disruption more so than the smooth areas. CONCLUSION: Retinal pigment epithelium (RPE) changes correlate with the health of the overlying EZ in choroideremia. The smooth FAF region likely represents early stages of the disease, with most of the area containing preserved EZ, whereas the mottled zone indicates more advanced stages and has mostly disrupted EZ. Because of the clear relationship between FAF findings and EZ integrity, FAF imaging can be used to monitor disease progression and identify areas of preserved EZ that could be rescued by gene therapy.

Outcomes of medium choroidal melanomas treated with ruthenium brachytherapy guided by three-dimensional pretreatment modeling.

PURPOSE: The Collaborative Ocular Melanoma Study (COMS) established iodine-125 (I-125) plaque brachytherapy for eye preserving treatment of medium-sized choroidal melanomas in the United States. Eye Physics I-125 plaque treatment modeled with Plaque Simulator (PS) software yields similar results to COMS. Herein, we report results from a series of 15 patients treated with ruthenium-106 (Ru-106) plaque brachytherapy using PS pretreatment modeling for plaque localization and dosimetry. METHODS AND MATERIALS: Fifteen patients with medium-sized choroidal melanomas (2.84-5.5 mm in apical height and a basal diameter of 7.8-12.6 mm) treated with ruthenium brachytherapy from 2003 to 2005 were evaluated retrospectively. Baseline and followup data were evaluated for tumor height, best corrected visual acuity, radiation retinopathy, radiation optic neuropathy, postradiation cataract formation, diplopia, and ptosis. Tumor response for both Ru-106 and I-125 plaques planned using the same PS pretreatment modeling was evaluated and compared. RESULTS: Isotope-specific radiation profiles were compared, and rates of local treatment failure (0%), optic neuropathy (6.7%), retinopathy (20%), and cataracts (33%) were evaluated. Five year-treated tumor heights were approximately 0.61 ± 0.29 (I-125, n = 16) and 0.53 ± 0.17 (Ru-106, n = 6) of their heights at diagnosis. CONCLUSIONS: This patient subset had background characteristics very similar to those of the COMS and patients treated at our institution with I-125 plaques. Treatment response was equivalent although radiation complications occurred slightly less frequently in the Ru-106 group compared with those treated with I-125. Image-guided three-dimensional pretreatment modeling for plaque localization and dosimetry seems to work equally as well for Ru as for I-125 plaques and justifies more extensive investigation.

Outcomes of choroidal melanomas treated with eye physics: a 20-year review.

IMPORTANCE: The University of Southern California Eye Physics plaques compare favorably with the Collaborative Ocular Melanoma Study plaques in terms of late adverse effects from radiation, metastasis, and local tumor recurrence. OBJECTIVE: To review the University of Southern California experience using Eye Physics plaques and Plaque Simulator software to treat choroidal melanomas and compare the outcomes with published results of the Collaborative Ocular Melanoma Study. DESIGN, SETTING, AND PARTICIPANTS: A retrospective case series of 82 patients treated for medium-sized choroidal melanoma from January 1, 1990, through December 30, 2010, using iodine 125 plaques and treatment simulation software developed at the University of Southern California. The dosimetric goal was 85 Gy in 7 days to a conformal volume enclosing the apex and a 2-mm margin surrounding the tumor base. Plaque localization was guided by the Plaque Simulator computer modeling system using preoperative imaging studies. MAIN OUTCOMES AND MEASURES: Primary outcome measures were local tumor control, globe preservation, and metastases. Secondary outcome measures were late radiation adverse effects including postoperative vision changes, optic neuropathy, radiation retinopathy, and cataract. RESULTS: The median follow-up for 82 patients was 46.8 months (range, 1-171 months). Globe preservation was achieved in 80 patients (97.6%); 2 patients underwent enucleation for local recurrence. Metastatic disease developed in 9 patients (11.0%). Retinopathy was seen in 31 patients (37.8%), optic neuropathy in 12 (14.6%), and cataracts in 26 (31.7%). Postoperatively, 21 patients (25.6%) lost more than 6 lines of Snellen visual acuity. CONCLUSIONS AND RELEVANCE: When considering rates of local recurrence, metastases, and late radiation adverse effects, the University of Southern California results for medium-sized choroidal melanomas using Eye Physics plaques compared favorably with Collaborative Ocular Melanoma Study data. The Plaque Simulator 3-dimensional tumor-modeling program developed at the University of Southern California is a reliable method for determining plaque positioning preoperatively and for treating this cohort of patients.