Amit Bhatt

Pharmacokinetics of bevacizumab and its effects on serum VEGF and IGF-1 in infants with retinopathy of prematurity.

PURPOSE To measure serum levels of bevacizumab and to compare serum levels of free vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) in infants who were treated with either intravitreal injection of bevacizumab (IVB) or laser for type 1 retinopathy of prematurity (ROP). METHODS Twenty-four infants with type 1 ROP were randomized into three treatment groups: IVB at 0.625 mg per eye per dose, IVB at 0.25 mg per eye per dose, and laser. Blood samples were collected prior to treatment and on posttreatment days 2, 14, 42, and 60. Weekly body weights were documented from birth until 60 days post treatment. Serum levels of bevacizumab, free VEGF, and IGF-1 were measured with enzyme-linked immunosorbent assay (ELISA). RESULTS Serum bevacizumab was detected 2 days after the injection, peaked at 14 days, and persisted for up to 60 days with half-life of 21 days. Area under the curve (AUC) analysis showed that systemic exposure to bevacizumab was variable among the subjects and was dose dependent. Serum free VEGF levels decreased in all three subgroups 2 days post treatment, with more significant reductions found in both IVB-treated groups, P = 0.0001. Serum IGF-1 levels were lower in both IVB-treated groups. CONCLUSIONS Clearance of bevacizumab from the bloodstream in premature infants takes at least 2 months. Although serum free VEGF levels decreased following either laser or bevacizumab treatment, the reductions were more significant in the IVB-treated groups. Potential long-term effects of systemic exposure to bevacizumab in infants need to be studied further.

Assessment of Plasma Cytokine Profile Changes in Bevacizumab-Treated Retinopathy of Prematurity Infants.

PURPOSE We compared changes of plasma angiogenesis cytokine profiles in infants who were treated with intravitreal injection of bevacizumab (IVB) for type 1 retinopathy of prematurity (ROP) with age-matched preterm non-ROP infants. METHODS Thirteen infants with type 1 ROP and 13 age-matched preterm non-ROP infants were included. Blood samples were collected prior to treatment (time 0) and 6 weeks after the treatment (time 42). Plasma levels of nine cytokines from the angiogenesis growth factor panel and seven soluble cytokine receptors were measured using a magnetic multiplex assay. RESULTS Plasma cytokine profiles changed from time 0 to time 42 in both groups. In bevacizumab-treated ROP infants, the following plasma angiogenesis growth factor and soluble cytokine receptor levels decreased significantly: soluble VEGF-A (sVEGF-A; P = 0.0001), sVEGF-D (P = 0.04), angiopoietin-2 (Ang-2; P = 0.002), sVEGF receptor 1 (R1) and R2 (P = 0.005), soluble IL-6 receptor (sIL-6R; P = 0.002), soluble glycoprotein 130 (spg130; P = 0.0001), and soluble TNF receptor (sTNFR) I and II (P = 0.0001). The following factors and receptors increased significantly: sVEGF-C (P = 0.05), placental growth factor (PlGF; P = 0.02), endothelin-1 (ET-1; P = 0.0001), and FGF-1 (P = 0.02). At time 42, sVEGF-A, sgp130, sIL-6R, sTNFR I, and sTNFR II were lower, and ET-1 level was higher, in bevacizumab-treated ROP infants compared to age-matched non-ROP infants. CONCLUSIONS The results suggest that bevacizumab treatment resulted in significant angiogenic cytokine profile changes in infants with severe ROP. The long-term clinical impact of these changes should be studied carefully.

Multimodality Image-Guided Sclerotherapy of Low-Flow Orbital Vascular Malformations: Report of Single-Center Experience

PURPOSE To evaluate the role of multimodality imaging tools for intraprocedural guidance and outcome evaluation during sclerotherapy of low-flow orbital vascular malformations. MATERIALS AND METHODS A retrospective review was performed of 17 consecutive patients with low-flow orbital malformations (14 lymphatic, two venous, and one venolymphatic) who underwent multimodality image-guided sclerotherapy between November 2012 and May 2015. Sclerotherapy technique, image guidance tools, and complications were recorded. Sclerotherapy outcome was evaluated using clinical response, magnetic resonance (MR) image-based lesion volumetry, and proptosis quantification. RESULTS There were 22 sclerotherapy sessions performed. Intraprocedural ultrasound (US), fluoroscopy, cone-beam computed tomography (CT) and MR image fusion were used for image guidance with 100% technical success. Resolution of presenting symptoms was observed in all patients at 1-month follow-up. Four major sclerotherapy complications were successfully managed. Statistically significant reduction in lesion volume (P = .001) and proptosis (P = .0117) by MR image analysis was achieved in all patients in whom 3-month follow-up MR imaging was available (n = 13/17). There was no lesion recurrence at a median follow-up of 18 months (range, 8-38 mo). CONCLUSIONS Multimodality imaging tools, including US, fluoroscopy, cone-beam CT, and MR fusion, during sclerotherapy of low-flow orbital malformations provide intraprocedural guidance and quantitative image-based evaluation of treatment outcome.

Long-term Visual and Ocular Sequelae in Patients With Congenital Cytomegalovirus Infection

Background: Cytomegalovirus (CMV) is the most common congenital viral infection in the United States. Visual and ocular sequelae in adolescents and adults who are congenitally infected with CMV have not been well studied. Better understanding of the long-term visual and ocular sequelae can help with early detection, intervention and appropriate educational accommodations. Methods: This study evaluated 237 patients (77 symptomatic, 109 asymptomatic and 51 control) who underwent a series of age-appropriate ophthalmologic, audiologic and neurodevelopmental examinations from 1982 to 2013. The frequency and etiology of visual impairment and other nonophthalmologic findings were recorded for each patient. Ophthalmologic findings were tabulated, and risk factors for abnormalities were analyzed. Results: Fourteen of the 77 (18.2%) symptomatic and none of the asymptomatic and control subjects had severe visual impairments (P ⩽ 0.006). Moderate visual impairment did not differ between symptomatic and asymptomatic subjects. Three asymptomatic subjects had retinal scars. The most common visual or ocular sequelae in the symptomatic group were strabismus (23.4%), chorioretinal scars (19.5%), cortical visual impairment (14.3%), nystagmus (14.3%) and optic nerve atrophy (11.7%). Three symptomatic patients had delayed visual deterioration because of later occurring retinal disorders: peripheral retinal scar, rhegmatogenous retinal detachment and Coats’ disease. Conclusion: Symptomatic CMV patients experienced more ophthalmologic sequelae and significantly worse visual outcomes than asymptomatic CMV and control patients. Later occurring retinal disorders were found in symptomatic patients, and there is no clear evidence that CMV can reactivate in the retinas of children who were congenitally infected. Major risk factors for severe visual impairment included symptomatic status, optic nerve atrophy, chorioretinitis, cortical visual impairment and sensorineural hearing loss.

Capture-based DNA methylation sequencing facilitates diagnosis and reveals potential pathogenic mechanisms in teratogenic diabetes exposure

Diabetic embryopathy (DE) describes a spectrum of birth defects associated with a teratogenic exposure to maternal diabetes in utero. These defects strongly overlap the phenotypes of known genetic syndromes; however, the pathogenic mechanisms underlying DE remain uncertain and there are no definitive tests that distinguish the diagnosis. Here, we explore the potential of DNA methylation as both a diagnostic biomarker and a means of informing disease pathogenesis in DE. Capture-based bisulfite sequencing was used to compare patterns of DNA methylation at 2,800,516 sites genome-wide in seven DE neonates and 11 healthy neonates, including five with in utero diabetes exposure. DE infants had significantly lower global DNA methylation (ANOVA, Tukey HSD p=0.045) than diabetes-unexposed, healthy controls (UH), with multiple sites showing large (mean methylation difference = 16.6%) and significant (p<0.001) differential methylation between the two groups. We found that a subset of 237 highly differentially methylated loci could accurately distinguish DE infants from both UH and diabetes-exposed healthy infants (sensitivity 80% -100%). Differentially methylated sites were enriched in intergenic (p<3.52×10-15) and intronic (p<0.001) regions found proximal to genes either associated with Mendelian syndromes that overlap the DE phenotype (e.g. TRIO, ANKRD11), or known to influence early organ development (e.g. BRAX1, RASA3). Further, by integrating information on cis-sequence variation, we found that 39.3% of loci with evidence for allele-specific methylation also showed differential methylation between DE and controls. Our study suggests a role for aberrant DNA methylation and cis-sequence variation in the pathogenesis of DE, and highlights the diagnostic potential of DNA methylation for teratogenic birth defects.