Walaa Elfar

Interests

No activities entered.

Courses

No activities entered.

Scholarly Contributions

Chapters

• Elfar, W. (2025).

  Abnormalities of Hepatic Protein metablism 

  . In Pediatric gastroenterological and Liver Disease 7th edition. Elsevier.
• Elfar, W., & Ghishan, F. (2025).

  Abnormalities of Hepatic Protein Metablosim 

  . In Pediatric Gastrointestinal and liver diseases.

Journals/Publications

• Govindappa, P. K., Elfar, J. C., Gupta, Y., Ellur, G., Gaber, A. A., Rawat, M., & Elfar, W. (2026). Biomarkers and immunomodulatory effect of erythropoietin in postoperative ileus. BMC research notes.
  More info

  Postoperative ileus (POI) is a type of intestinal motility disorder (IMD) that can occur after abdominal surgery. At present, there is no accepted treatment for POI and no reliable biomarkers to assess the status of POI. Erythropoietin (EPO) can promote the recovery of the intestine from various injuries, including POI. This study aimed to investigate the immunomodulatory role of EPO and to identify reliable biomarkers of POI.
• Drda, E., Ali, S., Fadel, H., Sun, B., & Elfar, W. (2025). Hepatocellular carcinoma arising from adenoma with ARID1A mutation in an adolescent patient with ATM germline mutation. Journal of surgical case reports, 2025(10), rjaf835.
  More info

  While hepatocellular carcinoma (HCC) is increasingly common in adults, it remains rare in children. Unlike adult HCC, which typically arises from cirrhosis, pediatric cases often occur without underlying liver disease. We report a 14-year-old male with a large hepatic adenoma containing multiple foci of HCC. Genetic testing revealed a germline ATM mutation and a somatic ARID1A mutation. We hypothesize that impaired DNA repair from the ATM mutation facilitated the ARID1A mutation, driving malignant transformation. This case underscores the importance of recognizing malignant potential in hepatic adenomas, utilizing appropriate imaging and pathology, and monitoring for associated cancers in genetically predisposed patients.
• Govindappa, P. K., Begom, M., Gupta, Y., Elfar, J. C., Rawat, M., & Elfar, W. (2023). A critical role for erythropoietin on vagus nerve Schwann cells in intestinal motility. BMC Biotechnology, 23(Issue 1). doi:10.1186/s12896-023-00781-x
  More info

  Background: Dysmotility and postoperative ileus (POI) are frequent major clinical problems post-abdominal surgery. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine that promotes recovery of the intestine in various injury models. While EPO receptors (EPOR) are present in vagal Schwann cells, the role of EPOR in POI recovery is unknown because of the lack of EPOR antagonists or Schwann-cell specific EPOR knockout animals. This study was designed to explore the effect of EPO via EPOR in vagal nerve Schwann cells in a mouse model of POI. Results: The structural features of EPOR and its activation by EPO-mediated dimerization were understood using structural analysis. Later, using the Cre-loxP system, we developed a myelin protein zero (Mpz) promoter-driven knockout mouse model of Schwann cell EPOR (MpzCre-EPORflox/flox / Mpz-EPOR-KO) confirmed using PCR and qRT-PCR techniques. We then measured the intestinal transit time (ITT) at baseline and after induction of POI with and without EPO treatment. Although we have previously shown that EPO accelerates functional recovery in POI in wild type mice, EPO treatment did not improve functional recovery of ITT in POI of Mpz-EPOR-KO mice. Conclusions: To the best of our knowledge, this is the first pre-clinical study to demonstrate a novel mouse model of EPOR specific knock out on Schwan cells with an effect in the gut. We also showed novel beneficial effects of EPO through vagus nerve Schwann cell-EPOR in intestinal dysmotility. Our findings suggest that EPO-EPOR signaling in the vagus nerve after POI is important for the functional recovery of ITT.
• Govindappa, P. K., Begom, M., Gupta, Y., Elfar, J. C., Rawat, M., & Elfar, W. (2023). A critical role for erythropoietin on vagus nerve Schwann cells in intestinal motility. BMC biotechnology, 23(1), 12.
  More info

  Dysmotility and postoperative ileus (POI) are frequent major clinical problems post-abdominal surgery. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine that promotes recovery of the intestine in various injury models. While EPO receptors (EPOR) are present in vagal Schwann cells, the role of EPOR in POI recovery is unknown because of the lack of EPOR antagonists or Schwann-cell specific EPOR knockout animals. This study was designed to explore the effect of EPO via EPOR in vagal nerve Schwann cells in a mouse model of POI.
• Elfar, W., Gurjar, A. A., Talukder, M. A., Noble, M., Di Lorenzo, C., & Elfar, J. (2021). Erythropoietin promotes functional recovery in a mouse model of postoperative ileus. Neurogastroenterology and motility, 33(2), e14049.
  More info

  Dysmotility and postoperative ileus (POI) are major clinical problems after surgical trauma and it is associated with increased intestinal inflammation and oxidative stress. Despite the high occurrence of POI following intra-abdominal surgeries, no effective treatment is currently available. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine with potent anti-inflammatory and anti-oxidative properties, and it is an FDA approved medicine for clinical use. While both EPO and EPO receptors (EPOR) are widely expressed in the gut, the role of EPO in POI is largely unknown. This study was designed to explore the possible beneficial effect of EPO in a mouse model of POI.
• Kovacic, K., Elfar, W., Rosen, J. M., Yacob, D., Raynor, J., Mostamand, S., Punati, J., Fortunato, J. E., & Saps, M. (2020). Update on pediatric gastroparesis: A review of the published literature and recommendations for future research. Neurogastroenterology and motility, 32(3), e13780.
  More info

  Due to scarcity of scientific literature on pediatric gastroparesis, there is a need to summarize current evidence and identify areas requiring further research. The aim of this study was to provide an evidence-based review of the available literature on the prevalence, pathogenesis, clinical presentation, diagnosis, treatment, and outcomes of pediatric gastroparesis.
• Elfar, W., Järvinen, E., Ji, W., Mosorin, J., Sega, A. G., Iuga, A. C., Lobritto, S. J., Konstantino, M., Chan, A., Finel, M., & Lakhani, S. A. (2019). A Novel Pathogenic Variant in a Sudanese Child with Type 1 Crigler-Najjar Syndrome. Drug metabolism and disposition: the biological fate of chemicals, 47(1), 45-48.
  More info

  Uridine diphosphate glucuronosyltransferases (UGTs) are key enzymes responsible for the body's ability to process a variety of endogenous and exogenous compounds. Significant gains in understanding UGT function have come from the analysis of variants seen in patients. We cared for a Sudanese child who showed clinical features of type 1 Crigler-Najjar syndrome (CN-1), namely severe unconjugated hyperbilirubinemia leading to liver transplantation. CN-1 is an autosomal recessive disorder caused by damaging mutations in the gene for UGT1A1, the hepatic enzyme responsible for bilirubin conjugation in humans. Clinical genetic testing was unable to identify a known pathogenic mutation in this child. Instead, a novel homozygous variant resulting in an in-frame deletion, p.Val275del, was noted. Sanger sequencing demonstrated that this variant segregated with the disease phenotype in this family. We further performed functional testing using recombinantly expressed UGT1A1 with and without the patient variant, demonstrating that p.Val275del results in a complete lack of glucuronidation activity, a hallmark of CN-1. Sequence analysis of this region shows a high degree of conservation across all known catalytically active human UGTs, further suggesting that it plays a key role in the enzymatic function of UGTs. Finally, we note that the patient's ethnicity likely played a role in his variant being previously undescribed and advocate for greater diversity and inclusion in genomic medicine.

Presentations

• Elfar, W. (2024).

  EPO in GI Dysmotility 

  . Pediatric Grad rounds. Virtual: Golisano Children's hospital- URMC.
• Elfar, W. (2026).

  Disorders of Gur BRain interaction (DGBI) management update 

  Functional Abdominal pain- Real or Not, here I caome!

  . Pediatric Grand rounds. in person and virtual: Banner University Medicine in Tucson.
• Elfar, W. (2024, November).

  EPO in intestinal dysmotility 

  . Pediatric Grand Rounds. Virtual: Golisano Children's hospital- University of Rochester Medical Center.