LYSINURIC PROTEIN INTOLERANCE WITH CHARAC TERISTIC BONE-MARROW ABNORMALITIES

Background. - The marrows of patients with lysinuric protein intoleran ce (LPI) are generally considered as normal, even though autoerythroph agocytosis has been observed in some of them. Case reports. - Lysinuri c protein intolerance was recognized in two 12 and 15-year-old brother s who had been diagnosed following an immuno-hematological investigati on. Clinical history had been characterized by a neonatal macrophage a ctivation syndrome (hepatosplenomegaly, pancytopenia, hypofibrinogenem ia and hypertriglyceridemia). A putative diagnosis of familial lymphoh istiocytosis had been ruled out because of unusual clinical and immuno logical course. Both brothers had displayed chronic aversion to high-p rotein foods, failure to thrive, osteoporosis and developmental delay. Metabolic investigations had revealed chronic hyperammonemia while ca tionic aminoaciduria (lysine, arginine and ornithine) was only present during L-citrulline supplementation. Bone marrow examinations had bee n performed during the neonatal period and during later metabolic inve stigations. They both displayed a peculiar red cell and granulocytes p hagocytosis by histiocytes and granulocytes precursors. Conclusions. - This aspect of bone marrow could be considered as a specific sign of LPI. This report suggests that appropriate metabolic investigations sh ould be performed in any unexplained macrophage activation syndrome.