Molecular biology of blood groups: cloning the Kell gene.
Explore the source record for details and available documents.
Cloning, Molecular↗
Biomedical subjects
W L Marsh
Publications and source records attributed to W L Marsh.
Molecular cloning and primary structure of Kell blood group protein.
The Kell blood group is a major antigenic system in human erythrocytes. Kell antigens reside on a 93-kDa membrane glycoprotein that is surface-exposed and associated with the underlying cytoskeleton. We isolated tryptic peptides and, based on the amino acid sequence of one of the peptides and by using the PCR, prepared a specific oligonucleotide to screen a lambda gt10 human bone-marrow cDNA library. Four clones were isolated, one containing cDNA with an open reading frame for an 83-kDa protein. All known Kell amino acid sequences were present in the deduced sequence; moreover, rabbit antibody to a 30-amino acid peptide, prepared from this sequence, reacted on an immunoblot with authentic Kell protein. The Kell cDNA sequence predicts a 732-amino acid protein. Hydropathy analysis indicates a single membrane-spanning region, suggesting that Kell protein is oriented with 47 of its N-terminal amino acids in the cell cytoplasm, and a 665-amino acid segment, which contains six possible N-glycosylation sites, is located extracellularly. Computer-based search showed that Kell has structural and sequence homology to a family of zinc metalloglycoproteins with neutral endopeptidase activity.
Amino Acid Sequence↗
Nonpigmented papillary carcinoma in a black thyroid gland.
A case of papillary thyroid carcinoma occurring in a 27-year-old man with black thyroid syndrome is reported. The tumor, in contrast to the remaining thyroid, was not pigmented. The significance and potential utility of the differential pigmentation are discussed.
Adult↗
Poorly differentiated ('insular') thyroid carcinoma. Report of two cases and review of the literature.
The clinical, histopathologic, immunohistochemical, and electron microscopic findings of two cases of poorly differentiated ("insular") thyroid carcinoma are reported and compared with the 25 cases previously described in the literature. These 27 cases occurred in eight men and 19 women, aged from 34 to 77 years. All but 2 presented with a thyroid mass. Eleven (41%) of the 27 patients experienced local recurrences following surgery, 17 (63%) had development of cervical lymph node metastases, 5 (19%) had development of mediastinal lymph node metastases, 11 (41%) had pulmonary metastases, and 9 (33%) had bone metastases, and 9 (33%) had bone metastases. At least 15 patients (56%) are known to have died of their disease, usually within 8 years of diagnosis. Pathologically, the tumors are distinctive and grow as solid islands (insulae) of small cells separated by artifactually created clefts. In some instances, small follicles are also noted within the insulae. All tumors were positive on immunostaining for thyroglobulin. In view of the propensity for local recurrences and lymphatic and hematogenous dissemination, a total thyroidectomy and neck dissection would seem advisable. Additionally, adjuvant external beam irradiation, systemic chemotherapy, and/or radioactive iodine therapy should also be considered.
Adenocarcinoma↗
The Kell blood group system: a review.
Explore the source record for details and available documents.
Animals↗
Abnormal membrane physical properties of red cells in McLeod syndrome.
McLeod red cells (RBCs) lack Kx antigens and have weak expression of the Kell antigens. Individuals who carry the McLeod phenotype have acanthocytic RBCs and a compensated hemolytic state. To elucidate the role of the protein on which the Kx antigens reside in maintaining membrane deformability, the rheologic properties of McLeod RBCs were determined by ektacytometry. RBCs were obtained from normal individuals and from four patients with McLeod syndrome. Osmotic gradient deformability profiles of McLeod RBCs showed decreased whole cell deformability. Resealed ghosts from McLeod RBCs also showed decreased deformability, partly because of the decreased cell surface area and partly because of an intrinsic membrane stiffness in this syndrome. For the measurement of membrane mechanical stability, resealed ghosts were subjected to constant high shear stress in the ektacytomer, and deformability was recorded continuously as the deformable ghosts fragmented into rigid spherical vesicles. Membranes from McLeod RBCs showed a noticeable increase in mechanical stability. Acquired causes of acanthocytosis, such as liver disease, did not cause the rheologic abnormalities observed in McLeod cells. Other abnormalities noted in McLeod RBCs were decreased RBC potassium content and an increased number of dense RBCs, as determined by centrifugation on a discontinuous density gradient. The data indicate that McLeod RBCs are rigid and have decreased surface area and that their membranes are intrinsically rigid with increased mechanical stability. These abnormalities may account for the reduced RBC survival observed in McLeod syndrome. The protein that carries the Kx surface antigen seems to be required for the maintenance of the normal physical function of RBC skeletal proteins.
Adult↗
Hairy cell leukemia involving an inguinal hernial sac.
A 37-year-old man with hairy cell leukemia was found incidentally to have a right inguinal hernia. Microscopic examination of the resected herniorrhaphy specimen disclosed dense transmural infiltration by hairy cells. Electron-microscopic and immunoperoxidase studies confirmed the presence of surface cytoplasmic projections and B cell phenotype, respectively, of the infiltrating cells. This case is, to our knowledge, the first reported instance of hairy cell leukemia involving a hernial sac and demonstrates the capacity of hairy cells to infiltrate unexpected soft-tissue sites.
Adult↗
Diffuse angiomatosis of the extremities presenting as a sarcoma.
Diffuse angiomatosis of the extremities is a rare condition characterized by extensive or multifocal benign mass-forming vascular lesions involving multiple tissue planes; histologically, adipose and fibrous tissue are admixed with vascular elements that vary from capillary proliferations to large vessels that are often structurally abnormal. Although diffuse angiomatosis most likely represents a hamartomatous form of arteriovenous malformation, it behaves clinically as a benign but slowly progressive and unresectable neoplasm. We describe a case of diffuse angiomatosis of the lower extremity that presented clinically as a soft-tissue sarcoma.
Angiomatosis↗
Purification and characterization of an erythrocyte membrane protein complex carrying Duffy blood group antigenicity. Possible receptor for Plasmodium vivax and Plasmodium knowlesi malaria parasite.
A murine monoclonal antibody, named anti-Fy6, which agglutinates all human red cells except those of Fy(a-b) phenotype was used for purification and characterization of Duffy antigens. Duffy antigens are multimeric red cell membrane proteins composed of different subunits of which only one, designated pD protein, reacts in immunoblots with the murine monoclonal antibody anti-Fy6. Affinity-purified detergent-soluble antigen-antibody complex obtained from red cells, surface-labeled with 125I yielded a complex pattern of bands when separated by polyacrylamide gel electrophoresis. Proteins that react with anti-Fy6 in immunoblots are: pA and pB (greater than 100 kDa) and pD (36-46 kDa). Electroeluted pD protein aggregates and generates bands of similar molecular mass to pA and pB proteins. Electroeluted pA and pB proteins disaggregate yielding pD protein. Oligomers and monomers of pD protein are present in red cells carrying Duffy antigens and absent in Fy(a-b-) cells. Six other proteins of molecular weight ranging from 68 to 21 kDa either associate or co-purify with pD protein. These proteins are only present in Duffy antigen positive cells. The pD protein is different in Fy(a+b-) and Fy(a-b+) cells by fingerprint analysis. Human antisera identify the same proteins in red cell carrying Duffy antigens as the murine monoclonal antibody anti-Fy6.
Animals↗
The Kmod blood group phenotype in a healthy individual.
This report describes a healthy blood donor whose red cells have weakened expression of Kell blood group antigens. Kell antigen activity could not be detected by flow cytometric analysis and was demonstrable only by sensitive serologic techniques. As with normal-strength Kell antigens, reactivity could be abolished by treatment with 2-aminoethylisothiouronium bromide (AET). The donor's red cells have Kx antigen activity. Other commonly tested blood group antigens (MNSs, Rh, P1, Lewis, Duffy, and Kidd systems) appear normal. Clinical and serologic examination showed that this case is different from previously described examples of modified Kell expression. The propositus's phenotype has remained unchanged for 19 months, which suggests that it is not a transient condition. However, family studies provide no evidence that it is inherited. A 93-kD protein, which reacted weakly by Western blot with rabbit antibody to Kell protein, was isolated from the propositus's red cells by immunoprecipitation. This finding was not reproduced in subsequent studies, which suggests that the quantity of Kell protein recovered was at the threshold level detectable by the technique used. The red cell phenotype is categorized as Kmod, of which this is the first example reported in a healthy individual.
Absorption↗
Hyperreactio luteinalis. Benign disorder masquerading as an ovarian neoplasm.
Hyperreactio luteinalis (HL) refers to moderate to marked cystic enlargement of the ovaries due to multiple benign theca lutein cysts and is most often associated with hydatidiform mole or choriocarcinoma. The cause of this condition is unknown, but is believed to be related to elevated levels of, or abnormal ovarian response to, human chorionic and pituitary gonadotropins. Only 47 cases of HL unassociated with trophoblastic disease have been previously reported in the English-language literature, mostly before 1974, and almost exclusively in the gynecologic literature. We present two additional cases of HL unassociated with trophoblastic disease and review the literature. One of our case reports documents the unusual occurrence of unilateral HL. Of the 49 cases described, 11 occurred with fetal hydrops (8 immunologic; 3 non-immunologic), 8 with multiple pregnancies, and 30 in otherwise normal single pregnancies. Hyperreaction luteinalis is most often bilateral and found incidentally at the time of cesarean section. However, HL may present during any trimester as an abdominal mass or acute abdomen. The natural course is postpartum regression. Recognition of HL is important, since misinterpretation at laparotomy or erroneous histologic diagnoses have resulted in unnecessary surgery, often with sterilization in 16 of the cases. A conservative approach is indicated with wedge biopsy and frozen section diagnosis. Oophorectomy is necessary only to remove infarcted tissue or to control hemorrhage.
Adult↗
Chondrolipoma of the breast.
Benign cartilage-containing mesenchymal tumors of the breast are extremely rare. We describe a patient with chondrolipoma of the breast who presented with a breast mass that was detected by routine mammography. Although the mammographic features of chondrolipoma are not specific, the histologic features are diagnostic and show a well-circumscribed mass composed of benign adipose tissue and lobules of mature cartilage. We also discuss the differential diagnosis of benign mesenchymal tumors of the breast.
Breast Neoplasms↗
Effect of phosphatidylserine on the shape of McLeod red cell acanthocytes.
The rare McLeod blood group phenotype is characterized by weak Kell antigens, lack of the common Kx antigen, and acanthocytic morphology. Previous studies that did not detect membrane or cytoskeletal protein abnormalities suggested a lipid disturbance. In normal red cells, dimyristoyl phosphatidylserine (DMPS) is transported across the membrane by an enzymatic process and accumulates in the inner leaflet of the membrane bilayer causing discocyte to stomatocyte shape changes. Scanning electron microscopy of McLeod red cells shows a mixture comprised of 15% discocytes, 51% with irregular surfaces, and 34% acanthocytes. On incubation with various concentrations of DMPS at 37 degrees C for periods up to two hours, McLeod red cells transported DMPS across the membrane and caused irregularly shaped and acanthocytic McLeod red cells to attain normal discocyte shape and later to become stomatocytes. Chlorpromazine, which at 0 degrees C preferentially partitions into the inner monolayer of the membrane, had a similar effect on the shape of McLeod red cells. This suggests that in McLeod cells acanthocytosis is due to a lack of lipid in the inner leaflet of the membrane bilayer but that the imbalance is not caused by defective transport of phosphatidylserine across the membrane.
Acanthocytes↗
Antibodies associated with the Kell blood group system.
Explore the source record for details and available documents.
Blood Group Antigens↗
Summary report of laboratories studying monoclonal antibodies in the Kell blood group system.
Explore the source record for details and available documents.
Animals↗
Hematologic evaluation of employees with leukopenia. Naval Weapons Center, China Lake, California.
Evaluation of 86 employees with a history of leukopenia at the Naval Weapons Center (NWC), China Lake, California, was done by exposure questionnaires, medical histories, physical examinations, peripheral blood smear, and bone marrow evaluations, including morphologic examination, stem cell culture, and cytogenetics. Forty-eight subjects were found to be leukopenic at the time of the study, and two subjects were found to have hairy cell leukemia. All subjects had positive exposure histories and were healthy at the time of the study. Review of peripheral smears identified the patients with marrow abnormalities. Bone marrow cultures revealed several patients with possible marrow suppression. Chromosome studies were not diagnostic. Five-year follow-up health questionnaires revealed no significant health problems; the two workers with hairy cell leukemia are alive and fully functional. Leukopenia in itself does not appear to be a risk factor for poor health, and it is unknown whether or not it may be a useful screening tool to identify workers at risk in toxic environments. Careful evaluation of blood cell counts and peripheral smears should be sufficient to identify people with potential marrow abnormalities.
Adult↗
Biochemical studies on McLeod phenotype red cells and isolation of Kx antigen.
Red cells of the McLeod blood group phenotype have weak Kell antigens, lack Kx antigen and have acanthocytic morphology. We have immunoprecipitated Kell antigens from McLeod red cells and show that they are markers on the same 93 kDa membrane protein that carries Kell antigens on normal red cells. However, as determined by Western immunoblotting, McLeod red cells have a marked deficiency of this protein. We have also studied the near-neighbour relationship of McLeod and common Kell red-cell membrane proteins by cross-linking intrinsic sulphydryl groups by oxidation, catalysed with orthophenanthroline and copper, or by cross-linking amino groups with dimethyl-3,3'-dithiobispropionimidate. Results were analysed by diagonal mapping in two-dimensional gels. No abnormalities of membrane protein inter-relationship were detected in McLeod red cells. We have isolated Kx antigen from K0 red cells by immunoprecipitation with human alloimmune anti-Kx serum, isolation of immune complexes from detergent-solubilized cell membranes with protein A-Sepharose and analysis of the eluted immune complex by SDS-PAGE under reducing conditions. Kx antigen is a marker on a red-cell membrane protein of approximately 37 kDa. Ko (Knull) red cells have about twice the amount of Kx antigen as do red cells of common Kell type. McLeod red cells have no detectable Kx antigen by serological tests or by immunoprecipitation.
Antigens, Bacterial↗
Blood grouping with the Olympus PK7100 testing system.
The Olympus PK7100, an automated microtitre blood typing machine, identifies, aliquots, and dilutes samples, adds reagents, photometrically detects agglutination, and records reaction results, with a throughput of 240 samples/h. A total of 20,147 donors was tested in parallel with the Groupamatic 360. Of these, 207 could not be ABO typed after two runs. Three samples typed as B by the Olympus were found to be A2B. Seventy-seven could not be typed for D after two runs. Of these, 55 were Rh positive and 22 negative. The Olympus identified 37 of 48 Du positive samples as Rh positive, while it typed three as Rh negative, and eight as 'uncertain'. None of these samples was identified as Rh positive by the Groupmatic 360. The Olympus PK7100 is accurate, reliable, easy to operate, and capable of high throughput with minimal operator intervention.
ABO Blood-Group System↗