Primary intestinal lymphangiectasia: French National Diagnosis and Care Protocol (PNDS; Protocole National de...

Primary intestinal lymphangiectasia or Waldmann's disease (ORPHA code: 90362) is a very rare disorder of unknown etiology, characterized by digestive lymphatic vessel dilations. The objective of the French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins) is to provide health professionals with information about the optimal management and care for patients, based on a critical literature review and multidisciplinary expert consensus. The PNDS, written by members of the French National Reference Centers for Rare Vascular diseases and Rare Digestive diseases, is available from the French Health Authority website. The latter allow lymph leakage (chyle) into the intestinal lumen that is responsible for protein-losing gastroenteropathy, combining hypoalbuminemia, lymphopenia and hypogammaglobulinemia. Diagnosis is usually made before the age of 3, but primary intestinal lymphangiectasia may be discovered in adults. Edema of the lower limbs is the main clinical sign and serous effusions (pleura, peritoneum, pericardium) are sometimes abundant. Exudative gastroenteropathy is confirmed by increased α₁-antitrypsin clearance. Esophagogastroduodenoscopy finds milky lesions corresponding to lymphangiectasias; duodenal biopsies confirm the diagnosis. Endoscopic videocapsule may be useful to evaluate the extent of the disease and/or if esophagogastroduodenoscopy is not contributory. In rare cases, the disease may be complicated by digestive or extra-digestive B-cell lymphoma in adults. Management is mainly based on a strict fat-free diet, combined with supplementation with medium-chain triglycerides, essential fatty acids and fat-soluble vitamins. Octreotide, a somatostatin analogue, has inconsistent efficacy, in combination with the fat-free diet and the sometimes-prescribed mammalian target of rapamycin-receptor inhibitor sirolimus, occasionally achieving positive effects. Diuretics and albumin infusions may be useful in addition to the fat-free diet. Intestinal resections are proposed for rare, localized, segmental forms of the disease.

Primary intestinal lymphangiectasia is a chronic disease requiring a prolonged restrictive and constraining strict low-fat diet supplemented with medium-chain triglycerides and fat-soluble vitamins. Its evolution can be complicated by more-or-less severe serous effusions and rare lymphoma. Life-long clinical and biological monitoring is required.