Association of X-Linked Chronic Granulomatous Disease with the Rare Mcleod Phenotype - a Case Report A

ASSOCIATION OF X-LINKED CHRONIC GRANULOMATOUS DISEASE WITH THE RARE MCLEOD PHENOTYPE - A CASE REPORT A. Siderow 1, J. Ries 1, B. Grossrieder 1, J. Reichenbach 2, R. Seger 2, M. Hergersberg 3, R. Röthlisberger 3 and B.M. Frey 1 1Blutspende Zürich, Rütistrasse 19, 8952 Schlieren, Switzerland 2Kinderspital Zürich, 8032 Zürich, 3Zentrum für Labormedizin, Kantonsspital, 5000 Aarau www.blutspendezurich.ch

Background McLeod syndrome (MLS) is characterized by the absence of the high frequency red blood cell (RBC) antigen Kx (> 99.9%), wea- kened expression of KEL antigens, acanthocytosis and hemolytic anemia. MLS results from mutations in the XK-Gen at Xp21.1. The XK-Locus is neighbouring the CYBB-Locus. Mutations of the X-chromosomal gene encoding gp91-phox (CYBB), a subunit of cytochrome b (-245) cause the X-linked granulomatous disease (X-CGD). X-CGD caused by deletion of the CYBB locus might be associated with the rare MLS. In these cases, the XK gene locus at Xp21.1 adjacent to CYBB locus is affected by an extend deletion of CYBB including Xp21.1 leading to disturbed expression of XK-KEL protein complex on RBC membrane and Kx neg RBC phenotype. To date, 8 different mutations translating into X-CGD associated MLS are known. All affected carriers are males as is expected in X-linked hereditary diseases.

Figure 1 Figure 2 Figure 3

Xp 22 Glycerolkinase-Mangel/ 2 Nebennierenhypoplasie Duchenne-Muskeldystrophie (gestört: Dystrophin) 21 McLeod Syndrom (gestört: Kx-Protein) septische Granulomatose 1 (gestört: Cytochrom b)

Retinitis pigmentosa

Short arm of X-chromosome with Pathognomonic red blood cell changes (acant- XK-Kell-Komplex as expressed in the normal red neighbouring loci of McLeod locus hocytes) in carriers of McLeod mutation blood cell membrane. Mutated or absent XK protein due to McLeod mutations leads to weakend expression of Kell antigens of the Kell protein. Case We report a 10-year old boy with X-CGD and therapy refractory pulmonary aspergillosis. Because of lack of HLA-identical stem cell donor, he was treated by genetically (gp91phox) corrected autologous blood stem cell transplantation (ABSCT). Prior to AB- SCT, he received repeatedly allogeneic granulocyte transfusions. Following mild conditioning for ABSCT, he became transfusion dependent and he received 19 RBC-units. On pretransfusion compatibility testing he presented with a high-titer anti-Kx antibo- dy (>1:8’000) preventing allocation of compatible allogeneic RBC from blood storage repository. Search of rare donor data fi les provided one healthy Swiss blood donor carrying McLeod RBC phenotype who was recruited for directed blood donation. Unfor- tunately, following transfusion of Kx neg RBCs of this donor, the patient developed additional RBC alloantibodies (anti-E, anti- K20) which required worldwide donor search. One compatible donor was identifi ed and provided several units of RBC that were successfully transfused. After suffi cient erythropoietic engraftment the patient became transfusion independent again. Later on, following replacement of an infected Port-à-cath system, the patient was again successfully transfused with Kx neg, K20 neg and E neg RBCs. After complete hematologic reconstitution, following gp91phox-modifi ed ABSCT, the patient reached suffi cient gra- nulocytic activity with complete clearance of infections, however the RBCs continued to be of McLeod phenotype without sign of hemolysis.

Figure 4: Clinical outcome of a patient with X-CGD associated MLS

130 Hemoglobin concentration Erythropoitin i.v. 120 RBC Transfusion 110 HTR: Hemolytic Transfusion Reaction 100 Anti-Kx

90 Anti-Km/-K20

80 Anti-E

Hemoglobin (g/l) Hemoglobin 70 10.8.-27.12.2007 ABSCT, Transfusion support with random products (19 EKs, 24 PKTs) 60 21.1.2008 Tx of Kx+ RBC HTR

50 05.8.2008 Tx of Kx- RBC no HTR 25.8.2008 Tx of Kx- RBC HTR 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 .2 01.9.2008 Tx of Km-, Kx-, E- RBC no HTR 1 1 2 2 3 3 3 4 4 5 5 6 6 7 7 8 8 9 9 9 0 0 1 1 2 2 1 1 2 2 3 3 3 4 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .1 .1 .1 .1 .1 .1 .0 .0 .0 .0 .0 .0 .0 .0 7 1 4 8 3 7 1 4 8 2 6 9 3 7 1 4 8 1 5 9 3 7 0 4 8 2 5 9 2 6 2 6 0 3 0 2 0 1 0 1 3 1 2 1 2 0 2 0 2 0 1 0 1 2 1 2 1 2 0 2 0 1 0 1 0 1 3 1 12.9.2008 Tx of Km-, Kx-, E- RBC no HTR 16.9.2008 Tx of Km-, Kx-, E- RBC no HTR

Molecular Characterisation of McLeod Mutation

By array comparative genomic hybridization, an exon-specifi c PCR of the XK-Gen, a deletion at Xp21.1 was identifi ed encompas- sing the complete XK-gene and the fi rst three (of 13) exons of the CYBB gene. Between the breakpoints 37’381’984+/-1bp and 37’533’472+/-1bp a deletion of 160’000bp was found by sequencing. This so far unknown deletion lead to the clinical phenotype of X-CGD associated MLS.

Conclusions X-CGD is rarely associated with hereditary MLS harbouring the risk of allosensitisation against the high-frequency RBC antigen Kx which may severely compromise transfusion support. Therefore, such patients require immunohematological work-up and ex- tensive organisational preparation for transfusion support prior to invasive regimens, e.g. surgery and hematopoietic stem cell transplantation. The genetic correction of CGD (CYBB locus) does not correct the genetic defect causing MLS.

42. Jahreskongress der Deutschen Gesellschaft für Transfusionsmedizin und Immunhämaologie (DGTI), 15.-18. September 2009, Rostock