Elevated Serum Creatine Phosphokinase in Subjects with McLeod Syndrome

Abstract

McLeod phenotype red cells of the Kell blood group system have acanthocytic morphology and reduced in vivo survival. The phenotype has an X-linked mode of inheritance and is found in some males who have no abnormality of leukocyte function and in some who have X-linked chronic granulomatous disease (CGD). We now describe an association between the McLeod phenotype and an abnormal elevation of serum creatine phosphokinase (CPK). The increase is of the MM isoenzyme type, derived from skeletal muscle or cardiac muscle, and muscle biopsy shows evidence of muscle cell changes. All of 11 males who have McLeod syndrome but do not have CGD have high levels of serum CPK. Males with McLeod syndrome and CGD may have normal or high levels of the enzyme. Individuals with other variant phenotypes in the Kell system have normal levels of serum CPK. Studies on a large kindred, which includes 5 people of McLeod phenotype, show high CPK levels only in the members of McLeod type. We conclude that the high level of CPK in the serum of these people is a reflection of a muscle cell anomaly and that in these individuals it is a pleiotropic effect of the X-linked gene that produces the McLeod red cell phenotype.

Muscle CT scan findings in McLeod syndrome and chorea-acanthocytosis

“…4 The distribution of involved muscles was distal limbs in 14, proximal in 7, both in 32, and not described in 6 cases. Muscle involvement has been documented in only 7 cases (25%) of McLeod syndrome, [1][2][3]5,[7][8][9][10][11][12][13] and involved the calves in 2, 3,12 proximal limbs in 2 11 and lower limbs in 1 7 ; no description was provided in 2 cases. 1 Muscle CT scan in this report disclosed that the striking contrast of severe involvement of some muscles and sparing of others was seen in both McLeod syndrome and chorea-acanthocytosis.…”

“…Neuromuscular manifestations include myopathy, areflexia, and involuntary movements, but the neurological details have been reported only in 28 cases. [1][2][3]5,[7][8][9][10][11][12][13] By contrast, muscle atrophy has commonly been reported in patients with choreaacanthocytosis, 4 but no evaluation have been done by computed tomography (CT) scan. We report here three patients with McLeod syndrome and two with chorea-acanthocytosis, distinguished by Kell blood group typing, in whom we evaluated the distribution of muscle involvement by CT scan.…”

A Rare Example of Weakened Expression of the Kell (K1) Antigen

“…These McLeod hete rozygotes, however, have a significant num ber of acanthocytes, the Kx antigen is signif icantly weakened and the CPK levels are elevated [6]. All the members of V.E.…”

Mcleod syndrome (hemolysis, acanthocytosis, and increased serum creatine kinase): potential confusion with polymyositis

“…We attempted to determine whether the Kx antigen was present or lacking on muscle cells, but the results were inconclusive. Erythrocytes are not the cause of the elevated serum creatine kinase activity in this syndrome (8).…”