With more widespread use of whole exome sequencing, new diseases are being uncovered. CHAPLE syndrome has recently been described: A Ozen et al. NEJM 2017; 377: 52-61.
CHAPLE syndrome comprises CD55 (decay-acclerating factor) deficiency with hyperactivation of complement, angiopathic thrombosis, and protein-losing enteropathy (PLE).
- In this report of 11 patients, 8 presented before 2 years of life.
- Disease manifestations included chronic diarrhea in 8, abdominal pain in 4, vomiting in 6.
- PLE features included hypoalbuminemia in 10 of 11, hypogammaglobulinemia in all 11, and primary intestinal lymphangiectasia (or Waldmann’s disease) in 5.
- Thrombotic disease: 3 with thrombosis, 2 with thrombocytosis
- Endoscopic findings (2 patients did not have endoscopy): mucosal ulcer in 4, lymphoid infiltrates in mucosa in 6
- Other features: recurrent lung infections in 5, hypothyroidism in 3, arthritis/arthralgia in 2, and clubbing in 5
- Patents’ T lymphocytes showed increased complement activation; cytokine modulation by CD55 were defective
- Treatment: Genetic reconstitution of CD55 or treatment with a complement-inhibitory therapeutic antibody reversed abnormal complement activation
In a related letter to the editor (NEJM 2017; 377: 87-9), Kurolap et al show that eculizimab therapy was helpful in a family with CHAPLE syndrome, reducing PLE and bowel movements within 100 days of initiation.
My take: CHAPLE syndrome needs to be considered in young patients with PLE (& primary intestinal lymphangiectasia).