CHAPLE stands for "CD55 deficiency with hyper-activation of complement, angiopathic thrombosis, and severe protein-losing enteropathy (PLE).

[1] CHAPLE syndrome is caused by mutations of the complement regulator CD55 gene leading to a loss of protein expression.

When CD55 is absent, the complement system attacks red blood cells and causes them to be destroyed (hemolysis).

[3][4][5] CHAPLE syndrome patients are generally diagnosed through a combination of clinical presentation, histology, and genetic testing.

Kurolap and colleagues treated patients with off-label eculizumab, a humanized anti-C5 monoclonal antibody and complement inhibitor, and it was shown to have beneficial outcomes over an 18-month period.