Human Leukocyte Antigen Gene Testing and Carbamazepine-Induced Toxic Epidermal Necrolysis: A Study of Pediatric Practice.

BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening drug-induced dermatologic conditions. SJS/TEN occurs in 1-10 per 10 000 patients taking carbamazepine (CBZ) (Pratt VM, McLeod HL, Rubinstein WS et al. Medical Genetics Summaries. National Center for Biotechnology Information US; 2018: 1-527). The development of SJS/TEN is associated with variable drug metabolism and presence of an at-risk HLA haplotype. HLA-B*15:02 and HLA-A*31:01 haplotypes can produce a hyperimmune response in the setting of CBZ use in patients of Asian and European descent, respectively (Schneider JA, Cohen PR. Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A concise review with a comprehensive summary of therapeutic interventions emphasizing supportive measures. Adv Ther. 2017; 34:1235-1244). OBJECTIVE: The US Food and Drug Administration (FDA) and the Canadian pharmacogenomics Network for Drug Safety (CPNDS) recommend that patients with high-risk ethnic backgrounds should be genetic tested before initiating CBZ (Sukasem C, Chaichan C, Nakkrut T et al. Association between HLA-B Alleles and Carbamazepine-induced maculopapular exanthema and severe cutaneous reactions in Thai patients. Journal of Immunology Research. 2018; 1-11).We sought out to assess the awareness of this in prescribing practitioners and their standard of practice. METHODS: We created a 15-question survey and distributed to pediatric neurologists and pediatricians at the University of Alberta. We hypothesized that there was a discordance between the standard of practice and the recommendation by the FDA and CPNDS. RESULTS: The survey results indicated a lack of awareness of the at-risk ethnicities for CBZ-induced SJS/TEN. HLA gene testing was rarely done prior to initiation of CBZ in high-risk patients. In addition, there was a lack of awareness for standard of care for genetic testing in Canada and worldwide. CONCLUSIONS: Our results demonstrate an evident gap between current prescriber practices and existing FDA and CPNDS recommendations to screen for HLA genotypes. We hope that this study captures the realistic potential to improve patient outcomes.

Femtosecond laser-induced cell-cell surgical attachment.

BACKGROUND AND OBJECTIVE: Laser-induced cell-cell surgical attachment using femtosecond laser pulses is reported. STUDY DESIGN/MATERIALS AND METHODS: We have demonstrated the ability to attach single cells using sub-10 femtosecond laser pulses, with 800 nm central wavelength delivered from a Ti:Sapphire laser. To check that the cells did not go through a cell-fusion process, a fluorescent dye Calcein AM was used to verify that the fluorescent dye did not migrate from a dyed cell to a non-dyed cell. The mechanical integrity of the attached joint was assessed using an optical tweezer. RESULTS: Attachment of cells was performed without the induction of cell-cell fusion, with attachment efficiency of 95%, and while preserving the cells' viability. Cell-cell attachment was achieved by delivery of one to two trains of femtosecond laser pulses lasting 15 ms each. CONCLUSIONS: Laser-induced ionization process led to an ultrafast reversible destabilization of the phospholipid layer of the cellular membrane. The inner cell membrane remained intact during the attachment procedure, and isolation of the cells' cytoplasm from the surrounding medium was obtained. A strong physical attachment between the cells was obtained due to the bonding of the membranes' ionized phospholipid molecules and the formation of a joint cellular membrane at the connection point. The cellular attachment technique, femtosecond laser-induced cell-cell surgical attachment, can potentially provide a platform for the creation of engineered tissue and cell cultures.

Global developmental delay, progressive relapsing-remitting parkinsonism, and spinal syrinx in a child with SOX6 mutation.

SOX6, a member of the SOX gene family, plays a key role in the development of several mammalian tissues and organs, including the central nervous system. Specifically, this gene modulates the differentiation and proliferation of interneurons in the medial ganglionic eminence, as well as oligodendrocytes in the spinal cord. We describe the case of a 4-year-old girl with global developmental delay and a spinal cord syrinx who presented with recurrent episodes of parkinsonian symptoms subsequent to febrile illnesses. The symptoms included gait instability, tremor, and dysarthria, with a progressive relapsing-remitting course over the span of 2 years. The patient was later found to have a large deletion-type mutation in the SOX6 gene. This case is the first report in humans implying a role for SOX6 in basal ganglia function, as well as spinal cord development.

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis: an unusual cause of autistic regression in a toddler.

Anti N-methyl-d-aspartate (NMDA) receptor encephalitis in children is associated with psychiatric changes, seizures, and dyskinesias. We present the first report of autistic regression in a toddler caused by this entity. A 33-month-old boy presented with decreased appetite, irritability, and insomnia following an upper respiratory tract infection. Over the next few weeks he lost language and social skills, and abnormal movements of his hand developed. Within a month, this patient came to fit the diagnostic criteria for autistic spectrum disorder. Upon investigation, anti-NMDA receptor antibodies were found in the boy's cerebrospinal fluid. He was treated with intravenous immunoglobulins and steroids, resulting in reacquisition of language and social skills and resolution of movements. Our case emphasizes the significance of suspecting anti-NMDA receptor encephalitis as the cause of autistic regression, even in an age group where the diagnosis of autistic spectrum disorder is typically made, and especially when presentation follows a febrile illness.