JMH variants: serologic, clinical, and biochemical analyses in two cases.
BACKGROUND
JMH is a high-frequency red cell blood group antigen that resides on a 76- to 80-kDa glycosylphosphatidylinositol-linked protein also known as CDw108. Antibodies with JMH specificity are often autoimmune and are usually, if not always, clinically benign. Some individuals with JMH-variant antigen produce alloantibodies to JMH, but little evidence concerning their clinical significance is available. This article reports on two patients who express a JMH-variant antigen and produced alloanti-JMH.


METHODS
Murine monoclonal antibodies and human antibodies to JMH were used in hemagglutination, radioimmunoassay, and Western blot testing of red cells from two JMH-variant patients; antiserum from one of these patients was also used in biochemical studies. In addition, in vivo survival of JMH-positive red cells was studied in the same patient.


RESULTS
Biochemically, both examples of red cells with the JMH-variant phenotype expressed a JMH protein with a molecular weight similar to that of the normal JMH protein. For both patients, family studies suggested an autosomal recessive pattern of inheritance. Survival study demonstrated reduced in vivo red cell survival in one patient.


CONCLUSIONS
JMH-variant phenotypes express a protein of normal molecular weight and are inherited in an autosomal recessive pattern. Furthermore, individuals with this phenotype can produce clinically significant antibodies.
Mudad
R
R
Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA.
Rao
N
N
Issitt
P D
PD
Roy
R B
RB
Combs
M R
MR
Telen
M J
MJ
D000368:Aged; D000818:Animals; D001789:Blood Group Antigens / Q000032:analysis*; D015153:Blotting, Western; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007519:Isoantigens; D008297:Male; D051379:Mice; D008970:Molecular Weight
D001789:Blood Group Antigens; D007519:Isoantigens