Poster Board III-532
Chronic Granulomatous Disease (CGD) is an inherited disease affecting innate immunity and leading to increased susceptibility to severe invasive fungal and bacterial infections. The X linked form of CGD is the most frequent and is caused by mutations in the gp91phox subunit of the NADPH oxidase complex encoding gene CYBB. McLeod syndrome patients present with late-onset neuromuscular troubles and a mild chronic haemolytic anaemia with acanthocytes. It is defined by the lack of expression of Kell antigens on erythrocytes and caused by mutations in the KX gene located close to the CYBB gene. The association of CGD and McLeod syndrome is a rare event. It can also be associated with Duchenne muscular dystrophy (DMD), retinitis pigmentosa or ornithine transcarbamylase deficiency. Patients : Four CGD patients patients were recently diagnosed with McLeod syndrome in Necker Hospital on a 2 year period of time. Their clinical and main biological characteristics are reviewed and a review of recent litterature Observations: In 1 patient, McLeod was evoked because of association of Duchenne myopathy and CGD revealed at 10 months with major hypotonia and recurrent infections. Initially, no acanthocytes were seen but Kell antigens testings led to confirmation of McLeod. Three other infants were diagnosed with CGD because of lung infections. One had lung biopsies revealing Nocardia sp. infection and received packed blood red cells. Four months after, an allo immunisation against red cells and a weakened Kell antigen expression led to McLeod diagnosis. For other patients, diagnosis was evoked because of anaemia and acanthocytes on blood smear analysis. All had confirmed by CYBB mutations with complete deletion. None had muscle weakness or retinal abnormality. For 2 infants, iron therapy and erythropoietin led to the correction of anemia.
Management and evaluation of X-linked CGD patients should require the search of McLeod syndrome. Biological diagnosis is sometimes uneasy, especially because acanthocytes are sometimes hard to identify on blood smears. Kell antigen reactivity screening could be easy to perform. When McLeod syndrome is diagnosed, patients are included in the French national registry for rare erythrocyte phenotype to receive appropriate transfusion management. Erythropoietin therapy could be useful in preventing chronic anemia.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.