A rare genetic condition which causes inflammatory bowel disease (IBD) can be successfully treated by bone marrow transplant, according to University of Manchester and Manchester University NHS Foundation Trust researchers. The disease, called G6PC3 deficiency, affects around one in a million people and causes inflammation of the bowel, as well as lung infections. The team also showed that in affected patients, white blood cells called neutrophils trigger inflammation when exposed to gut bacteria, despite treatment with commonly available biological therapies.
The patients were treated at the Royal Manchester Children's Hospital (part of Manchester University NHS Foundation Trust (MFT)) one of the world's leading centres for paediatric bone marrow transplantation, under the direction of Professor Rob Wynn. Dr Anu Goenka carried out the laboratory work as part of his PhD and he was funded by both a Medical Research Council Clinical Research Training Fellowship, as well as a Fellowship from the European Society for Pediatric Infectious Diseases (ESPID).
G6PC3 is important in sugar metabolism, critical for providing energy for neutrophils, which struggle to divide and function when it is deficient. Neutrophils (which form pus are deployed by the body to remove bacteria, particularly in the gut and lungs. The team examined neutrophil function and response to bone marrow transplant in four children with G6PC3 deficiency-associated IBD. The children's IBD had failed to respond to other immune therapies including steroids and biologics.
After the treatment, the symptoms of IBD went into remission in all of the patients. Three of the patients are now three to four years post-transplant and still in remission.
"Although IBD caused by G6PC3 deficiency is extremely rare and difficult to diagnose, it's thrilling that we have found a way to successfully treat it in these four children,” said Dr Peter Arkwright, senior lecturer at the University of Manchester and consultant in paediatric immunology, Royal Manchester Children's Hospital, led the study. “It's rare to say a cure has been found for any disease, but I think in this case, it's perfectly accurate to say this. Our paper has also shown beyond any doubt that IBD G6PC3 deficiency can cause IBD."
Professor Tracy Hussell, director of the Lydia Becker Institute of Immunology and Inflammation and NIHR Manchester Biomedical Research Center researcher, was co-lead.
Children with the deficiency are often diagnosed in the first few years of their life, though some are not diagnosed until they are 11 and 12, and because of difficulties in detecting the disease or receiving transplant, adults may also be affected. Bone Marrow transplant donors are either relatives or members of a bone marrow registry. The donated marrow is infused into a vein once the child has had chemotherapy. Around ten days after transfusion, new neutrophils appear, although the immune system takes between three and four months to recover. Most patients stay in isolation in a ward for three to four weeks before going home to isolate for a further few months.
“We therefore conclude that G6Pase‐β (and therefore cytoplasmic glucose availability in neutrophils) has an important role in mucosal immunity and increased neutrophil inflammatory output may drive enteritis in patients with G6PC3 deficiency,” the authors concluded. “Future studies should seek to test whether G6PC3 deficiency‐associated IBD can be ameliorated by rescuing neutrophils from death, by lowering 1,5‐anhydroglucitol‐6‐phosphate levels with therapeutic inhibitors of the kidney glucose transporter SGLT2.22 In the interim, we propose that clinicians check for IBD in patients with G6PC3 deficiency and consider HSCT when IBD is difficult to control.”
The paper, 'Neutrophil dysfunction triggers inflammatory bowel disease in G6PC3 deficiency', was published in the Journal of Leukocyte Biology..
To access the paper, please click here