Diabetes mellitus (DM) is a metabolic disorder of the proteins, lipids, and carbohydrates, results in hyperglycemia. Abnormalities in the function of insulin on target cells, its release from beta cells, or both may contribute to DM. The purpose of this research was to assess the progression of diabetic retinopathy (DR) to the levels of serum brain-derived neurotrophic factor (BDNF), glycated hemoglobin (HbA1c), and biochemical parameters. The study included 44 normal control subjects, 44 diabetic participants, who were separated into four groups based on their diabetes status and the results of fundoscopic examination. A commercial enzyme-linked immunosorbent assay kit was used to measure the levels of BDNF in the serum. The analysis revealed that diabetics had significantly lower serum BDNF levels than non-diabetics (p< 0.001). Also, there was a significant reduction in BDNF levels with the development of proliferative diabetic retinopathy in comparison with diabetics without DR (p < 0.001). In conclusion, serum BDNF levels decreased significantly in diabetics with and without DR compared to apparently healthy individuals, as well as with the progression of DR.

Autism is a neurodevelopmental disorder with a significantly increased incidence rate across the world over the past few years. Toxoplasmosis and cytomegalovirus (CMV) infection are globally prevalent and have been associated with diverse neurological and psychiatric disorders. A few studies have demonstrated the role of toxoplasmosis and CMV as potential etiological factors for autism. Accordingly, this study was performed to estimate the relationship between toxoplasmosis and CMV infection in children with autism as well as to assess their impact on the Childhood Autism Rating Scale (CARS) score. A total of 45 autistic children (6 girls, 39 boys) and 45 (21 girls, 24 boys) healthy control children were enrolled in our study. Their blood samples were collected and tested for the presence of Toxoplasma and CMV (IgG and IgM) antibodies and DNA by ELISA and real-time PCR (RT-PCR), respectively. Toxoplasmosis was detected in 11 (24.4%) autistic children through the ELISA [10 (22.2%) IgG + /IgM − and 1 (2.2%) IgG + /IgM +]; however, RT-PCR assay recorded only 1 positive case (2.2%), while it was detected in 10 (22.2%) control children through ELISA [9 (20%) IgG + /IgM − and 1 (2.2%) IgG + /IgM +] and 1 (2.2%) by RT-PCR. On the other hand, CMV infection was detected in all autistic children with 44 (97.8%) testing positive by ELISA [24 (53.3%) IgG + /IgM − , 18 (40%) IgG + /IgM + and 2 (4.4%) IgG − /IgM +] and 25 (55.6%) testing positive by RT-PCR assay. In addition, ELISA assay recorded 43 (95.6%) [19 (42.2%) IgG + /IgM + and 22 (48.9%) IgG + /IgM − and 2 (4.4%) IgG-/IgM +] and RT-PCR recorded 21 (46.7%) positive samples in control children with CMV. No significant difference was noted between autistic and control children for the overall prevalence of Toxoplasma or/and CMV infection. Similarly, the CARS score indicated a non-significant difference with Toxoplasma or/and CMV infection. Our data does not show an association between autism and toxoplasmosis or/and CMV infection. Nevertheless, considering that autistic children are at a high risk of contracting these infections, further studies with a larger sample size are recommended.