Ashraf Abu-Seida

BACKGROUND: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease. The autoimmune regulator () is a master regulator of self-tolerance development. mutations lead to the development of autoimmune polyglandular syndrome type 1 while polymorphisms have been linked to organ-specific autoimmunity. The study is aimed at addressing the association between polymorphisms, rs2075876 (G > A) and rs760426 (A > G), and SLE susceptibility and expression in Egyptian patients.

METHODS: Ninety-nine patients were included. One hundred and ten, and 123 control subjects were genotyped for rs2075876 and rs760426, respectively. Lupus severity was assessed using the Lupus Severity of Disease Index and Lupus Severity Index (LSI). Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) damage index was considered. Genotyping was done using StepOne Real-Time PCR. rs760426 GG was more frequent in the patients under the genotype level (14.1% vs. 4.9%, = 0.032) and recessive model (14.1% vs. 4.9%, = 0.017, OR = 3.2 (1.2-8.7)). Musculoskeletal involvement and nephritis were associated with rs2075876 under the dominant (97.9% vs. 80.8%, = 0.009, OR = 11 (1.3-89.2)) and recessive models (100% vs. 69.3%, = 0.032), respectively; and both were linked to rs2075876 at the allelic level: 98.3% vs. 85%, = 0.005, OR = 10.1 (1.3-76.6) and 82.8% vs. 68.6, = 0.041, OR = 2.2 (1-4.7), respectively. Patients with rs2075876 A alleles had a higher damage index ( 1 ± 1.3 vs. 0.6 ± 1.1, = 0.045) while the LSI was greater in patients with rs2075876 (8.5 ± 0.5 vs. 7.8 ± 1.3, = 0.002) and rs760426 (8.6 ± 11 vs. 7.8 ± 1.2, = 0.031) under the recessive models. rs760426 could share in SLE susceptibility while rs2075876 could influence the disease expression and burden in Egyptian patients.

PURPOSE: To quantitatively compare microvascular features in the macula of patients with diabetic retinopathy (DR) using fluorescein angiography (FA) and optical coherence tomography angiography (OCTA).

METHODS: Patients with DR were recruited from the Cairo University Hospital. FA was performed using a Topcon TRC-50DX or Heidelberg Spectralis HRA+OCT. OCTA was performed using an Optovue RTVue-XR Avanti. FA images were cropped and aligned to the corresponding OCTA images using i2k Align Retina software. The foveal avascular zone (FAZ), area of ischemia, and microaneurysms (MAs) were manually quantified using ImageJ. The fractal dimension (FD) was calculated from each skeletonized image using the FracLac plugin of ImageJ after retinal vascular segmentation.

RESULTS: Twenty-four eyes of 17 patients were evaluated, but only 18 eyes were successfully aligned. There was no difference in FAZ area measured for FA and OCTA images. Compared with OCTA images, FD was significantly less for FA images (1.66 ± 0.048 versus 1.72 ± 0.023, < .001). Significantly more MAs were identified on FA images (102 ± 27.5) compared with OCTA (47.5 ± 11.7, < .0001). The number of MAs on FA correlated with decreasing best corrected visual acuity (r = 0.315, = .015) and increasing central macular thickness (r = 0.492, = .001). No such associations were found with MAs detected on OCTA. Nevertheless, the area of ischemia in the FA images (8.5 ± 4.1%) was significantly smaller compared with the area measured in both the superficial (30.7 ± 9.5%) and deep capillary plexus (21.6 ± 10.9%) of the OCTA ( < .001). Interestingly, number of MAs in the FA images correlated with increasing area of ischemia in the FA (r = 0.568, < .001) but only the superficial segment of the depth-resolved OCTA scans (r = 0.539, < .001).

CONCLUSIONS: OCTA is a non-invasive tool capable of resolving the retinal vasculature in greater detail when compared with FA but detects significantly fewer MAs. Automatic alignment facilitates quantitative comparison of the microvascular features in DR.