Radioactive labeling techniques for the identification of G antigen in the human Rh blood group system

The G antigen is one of the erythrocyte membrane Rh antigens. The amount of Rh antigen present on the red blood cell is about 10(-15) g and radioactive labeling of membrane proteins is a useful method for its identification and characterization. In this paper, we compare 4 labeling techniques. Using a human monoclonal anti-Rh(G) antibody and an immunofixation technique, we located the G antigen on a polypeptide of an average molecular weight of 28,000 Da.

Human monoclonal antibodies against blood group antigens. Preparation of a series of stable EBV immortalized B clones producing high levels of antibody of different isotypes and specificities

The EBV immortalization technique was used to produce stable clones, from B lymphocytes, secreting human monoclonal antibodies to Rh(D), Rh(G), Rh(c), Rh(E), Kell, A and A1 blood group antigens. These clones were obtained from peripheral blood lymphocytes of hyperimmunized plasmapheresis donors or from spleen lymphocytes of immunized patients. Mean levels of antibody concentration varied between 4 and 50 micrograms/ml. The antibodies obtained were of IgG1, IgG2, IgM or IgA class. Most of the clones have been stable for growth and antibody production during long periods of continuous culture, extending upto 4 years. Hybridization of two clones was effected with the human lymphoblastoid cell line KR-4 and with the mouse myeloma X63-Ag8.653, but did not result in any marked improvement of clone characteristics. One of the anti-Rh(D)-producing EBV-transformed clones was used to produce an anti-Rh(D) typing reagent which has proved satisfactory for 2 years in routine blood typing in several laboratories.

Difference in kinetics of hematopoietic reconstitution between ALL and ANLL after autologous bone marrow transplantation with marrow treated in vitro with mafosfamide (ASTA Z 7557)

The kinetics of hematopoietic recovery after autologous bone marrow transplantation (ABMT) reflect the hematopoietic capacity of the infused marrow. In vitro treatment of marrow with high doses of mafosfamide (ASTA Z 7557) alters the hematopoietic regenerative capacity of the graft. Thirty-two patients with acute leukemia (12 acute lymphoblastic leukemia (ALL) and 20 acute non-lymphoblastic leukemia (ANLL] with 27 in complete remission and five in partial remission were consolidated with cyclophosphamide (60 mg/kg x 2) and total body irradiation (10 Gy), followed by reinfusion of autologous marrow treated in vitro with mafosfamide. The marrow of each patient had been incubated with the highest tolerable dose of mafosfamide, individually predetermined from a preincubation test. We report here that the kinetics of engraftment are strikingly different in ANLL and ALL patients. In the ANLL group recovery to 0.1% reticulocytes took a median of 20.5 days (range 14-32) versus 15 (11-28) in the ALL group; 33.5 days (18-45) versus 19 (15-30) for leukocytes to reach 1.0 x 10(9)/l; 35 (19-60) versus 20.5 (15-30) for neutrophils to reach 0.5 x 10(9)/l; 110+ (45-480+) versus 50 (23-90) for platelets to reach 50 x 10(9)/l (p less than 0.01 and p less than 0.05). Detection of granulocyte-macrophage progenitors (CFU-GM) regeneration in marrow aspirates post-ABMT was delayed in ANLL (p less than 0.05). Neither the nature of the previous induction therapy, nor the status of the blood or bone marrow at the time of collection (CFU-GM and erythroid burst-forming units/ml) nor the stem cell sensitivity to mafosfamide, nor the doses of progenitor cells infused could explain these differences. We interpreted these observations as suggesting that the engraftment potential has been more severely altered in ANLL than in ALL, which may reflect both the intensity of the in vitro treatment and the intrinsic fragility of the stem cell pool in ANLL.

Human monoclonal antibody against Rh(D) antigen: partial characterization of the Rh(D) polypeptide from human erythrocytes

A human monoclonal anti-Rh(D) antibody produced by an Epstein-Barr virus (EBV)-transformed B-cell line (IgG1(lambda), clone H2D5D2) has been purified on protein A-Sepharose column and used for binding studies and immune precipitation of the blood group rhesus (Rh) antigens. Scatchard plot analyses show that the 125I-labeled antibody (iodo-gen procedure), binds to 1.09 X 10(5), 0.43 X 10(5), and 0.32 X 10(5) antigen sites on each D--/D--, R2R2 and R1R1 RBC, respectively, with an association constant of approximately 0.6 X 10(8) mol/L-1. Immune precipitation studies indicate also that the Rh(D) antigen of the Rh(D)-positive RBCs is carried by a 29 kd polypeptide as deduced from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). No material could be precipitated from Rh(D)-negative or Rhnull RBCs. These results indicate that the monoclonal and the polyclonal human anti-Rh(D) behave similarly. A sample (Blo., presumed genotype R2r or R0R2) showing an increased number of antigen sites (0.76 X 10(5)/cell) and a high binding constant (5.7 X 10(8) mol/L-1) was used, as well as D--/D-- RBCs, for further purification of the 29-kd component. Extraction by Triton X-100 (0.1% to 5%) of the immune complexes formed between the membrane-bound Rh(D) antigens and the monoclonal antibody as well as a direct quantitative estimate of the 29-kd component, suggest that the Rh(D) polypeptide is loosely bound to the skeleton, since less than or equal to 80% can be solubilized from the membrane. In similar conditions, glycophorin A showed a slight association with the Triton-insoluble residue, whereas glycophorin B was easily and completely extracted. In contrast, both the minor RBC sialoglycoproteins, glycophorin C and glycoprotein gamma, remained predominantly bound to the membrane skeleton. The purified Rh(D) polypeptide obtained from Blo. and D--/D-- RBCs by immunoprecipitation and preparative gel electrophoresis was homogenous as judged by SDS-PAGE. Amino acid composition indicated that the Rh(D) protein contained sulfhydryl groups which are essential for biological activity.

Study of anti-Fya in five black Fy(a-b-) patients

Fya antibodies were detected in 5 Fy(a-b-) black patients during a 5-year period. The Duffy phenotype was confirmed using anti-Fya, anti-Fyb, and anti-Fy3 by an adsorption-elution technique. These 5 patients had sickle cell disease and had received multiple blood transfusions. The antibodies were all found during the investigation of a hemolytic transfusion reaction or failure to achieve the desired red cell increments after transfusion.

[Demonstration of specific binding sites for carp gonadotropin in ovary membrane preparations of Anguilla (Anguilla anguilla L.)]

Membrane preparations from silver eel ovary bind specifically labeled carp gonadotropin (cGTH 125I); similar preparations from kidney, liver, brain, and muscle exhibit either no or negligible specific binding. cGTH and partially purified eel pituitary extract, but neither hCG nor bTSH, inhibit cGTH 125I specific binding in a dose-dependent way. However, a high membrane concentration can bind hCG 125I and this binding is partly inhibited by excess hCG, thus suggesting the existence of a relatively small number of sites able to recognize this hormone. Studies of either cGTH inhibition of cGTH 125I specific binding or cGTH 125I dose-dependent binding have permitted, according to Scatchard, the binding parameters to be determined. Specific binding seems to have two components: one with low affinity and high capacity, and the other with high affinity (Kd = 1.2 10(-10) M) and low capacity (N = 0.2 fmol/mg ovary).

Idiotypic specificity of a human monoclonal anti-Rhesus(D) antibody

A human monoclonal IgG anti-Rhesus(D) (H2D5D2) obtained after transformation of lymphoid cells by Epstein-Barr virus was purified from culture supernatant by affinity chromatography. Rabbits were immunized with the monoclonal anti-D. The rabbit antisera, after appropriate absorption, reacted only against the immunizing monoclonal anti-D. The antiidiotypic antibodies (anti-id ab) were purified and gave a complete inhibition of the monoclonal anti-D, whereas no inhibition was observed with monoclonal or polyclonal IgG or with sera containing high titres of anti-D. Polyclonal anti-D obtained from 118 immunized blood donors were coated on Rh-positive red cells. Agglutination by anti-id ab was observed in 4 cases (3.4%), indicating a cross-reactivity between the monoclonal anti-D and the polyclonal anti-D present in the sera of some immunized donors.

[Rare phenotypes of alpha-1 antitrypsin: study of a case of the M1X variant]

Alpha-1 antitrypsin is the major component responsible for the normal alpha 1 band in human serum. Some genetic variants giving double alpha-1 band, may be associated with pathological process. In the course of a systematic screening of blood donors a double-band alpha-1 pattern was observed in a serum, due to the heterozygous expression of a genetic variant of the PI system. A possible clinical significance of the variant was investigated by characterizing it. The very rare allotype PI*X was identified and its frequency in the population of french blood donors was estimated around to one for 10,000.

An acute leukaemia augured before clinical signs by blood group antigen abnormalities and low levels of A and H blood group transferase activities in erythrocytes

A mixed field agglutination pattern with anti-A reagents and very low levels of A and H blood group antigen specific transferase activities were found in the erythrocytes of a 4-year-old girl who presented no clinical signs of haematological disease. Blood and marrow examination displayed some features consistent with a moderate dysmyelopoietic state. 18 months later an acute myeloblastic leukaemia confirmed the suspected haematological malignancy.

Failure of bone marrow cryopreservation in chronic granulocytic leukemia: relation to excessive granulo-macrophagic progenitor pool

Autologous bone marrow transplantation (ABMT) in chronic granulocytic leukemia (CGL) aims at reversing the acute or acceleration phases by injection of stem cells collected during the chronic phase. This study was designed to explain an unusual rate of delayed engraftment (50%) in our experience of ABMT in CGL patients. We investigated all the factors possibly responsible for abnormal perpetuation of aplasia following infusion of cryopreserved marrow stem cells. The study of CFU-gm recovery in 41 bags of frozen marrow from 25 patients revealed an overall deficiency with a mean CFU-gm recovery of 55 +/- 38% in CGL patients versus 73 +/- 15% in the control group (p less than 0.001). Our data also showed an inverse linear relation (r = -0.40, p less than 0.05) between CFU-gm concentration and recovery after freezing. A good CFU-gm recovery (greater than or equal to = 50%) was observed in 70% of cases when the concentration was less than 3700 CFU-gm/ml as compared to 30% of cases when the concentration was over 3700 CFU-gm/ml (p less than 0.001). The lack of improvement by diluting rich CFU-gm marrows to reduce CFU-gm concentration/ml, as well as the absence of relationship between CFU-gm recovery after freezing and nucleated cells concentration, suggest a particular fragility of CGL stem cells to freezing, probably related to their excessive amplification. At the present time, we strongly recommend that the highest possible dose of progenitor cells be cryopreserved, preferably at a low concentration, in patients with CGL, and particular attention devoted to the freezing procedure in each individual patient, with numerous appropriate efficiency tests.

Recovery of CFU-GM from cryopreserved marrow and in vivo evaluation after autologous bone marrow transplantation are predictive of engraftment

In 18 patients with non-Hodgkin's lymphomas or solid tumors treated with intensive chemotherapy and/or total-body irradiation followed by autologous bone marrow transplantation (ABMT), we assessed the value of granulocyte-macrophage progenitor cells (CFU-GM) monitoring to predict engraftment. We studied CFU-GM in cryopreserved marrow and attempted to settle whether detection of CFU-GM in vivo after ABMT has a predictive value on engraftment. Our data showed: The absence of linear correlation linking recovery of hematopoiesis to the dose of CFU-GM/kg infused. The existence of a CFU-GM threshold in respect to engraftment. Patients receiving doses of CFU-GM greater than 10(3)/kg had significantly faster recovery kinetics for hematopoiesis than did patients receiving doses below this threshold, with median recoveries to 0.5 and 1.0 X 10(9) neutrophils/liter, respectively, on days 14 and 15 versus days 29 and 31.5 (p less than 0.05 and p less than 0.02) and median recoveries to 1.0 and 2.5 X 10(9) leukocytes/liter respectively, on days 12.5 and 16 versus days 28 and 30.5 (p less than 0.05 and p less than 0.02). Considering the entire course of events during the first four weeks, we were able to show that white blood cell recovery was significantly faster in the group of patients receiving doses of CFU-GM greater than 10(3)/kg (p less than 0.001). Sequential studies of the reappearance of CFU-GM in marrow and peripheral blood indicated that the kinetics of CFU-GM recovery in vivo after ABMT predict engraftment. By day 7 after the graft, CFU-GM were already detectable in the marrow at a level of 10% of the dose infused for patients with optimal engraftment--median time to recovery to 1.0 and 2.5 X 10(9) leukocytes/liter and 1.0 X 10(9) neutrophils/liter on days 11, 15, and 14.5 versus days 18, 23, and 23 (p less than 0.02, less than 0.05, and less than 0.05), respectively after. On day 10 after ABMT, a 15% CFU-GM level in bone marrow confirmed engraftment, with a significant correlation of all parameters studied--1.0 and 2.5 X 10(9) leukocytes/liter (p less than 0.02 and less than 0.01), 0.5 and 1.0 X 10(9) neutrophils/liter (p less than 0.05), 50.0 and 100.0 X 10(9) platelets/liter (p less than 0.05). On day 14, a 50% CFU-GM level was reached in all patients with optimal engraftment; p less than 0.01 on 1.0, and 2.5 X 10(9) leukocytes on 0.5 and 1.0 X 10(9) neutrophils/liter. The detection of circulating CFU-GM in the blood by day 10 or 14 indicated engraftment.(ABSTRACT TRUNCATED AT 400 WORDS)

Autologous bone marrow transplantation using marrow incubated with Asta Z 7557 in adult acute leukemia

The sensitivity of human myeloblastic leukemic (CFU-L) and normal hemopoietic stem cells (CFU-GM and BFU-e) to Asta Z 7557 (INN Mafosfamide) was studied with regard to autologous bone marrow transplantation (ABMT) with cleansed marrow for consolidation therapy in adult patients with acute leukemia (AL) in remission. Establishment of the dose-response curves for CFU-GM (n = 37), BFUe (n = 11), and myeloblastic CFU-L (n = 9) demonstrated a wide range of sensitivity from patient to patient for all three progenitors. Whereas CFU-L, CFU-GM, and BFU-e grown in semisolid cultures disclosed similar sensitivities to Asta Z 7557, long-term culture (LTC) studies (n = 41) indicated a higher resistance of early progenitors. In an effort to achieve a maximum tumor cell kill and yet spare a sufficient amount of normal stem cells to ensure consistent engraftment, we defined the optimal dose for marrow cleansing as the dose sparing 5% CFU-GM (LD95). This dose was established from a preincubation test (PIT) realized on a 10-mL marrow aspirate taken 15 days before marrow collection in each individual patient. Twenty-four adult patients while in remission of AL (20 in complete remission, four in partial remission) were consolidated by cyclophosphamide 60 mg/kg X 2 and total body irradiation at 10 Gy followed by ABMT with marrow cleansed by Asta Z 7557 according to the specification described above. Patients were divided in two groups: group 1, unfavorable prognosis (11 patients); group 2, standard prognosis [13 patients in first complete remission (CR)]. All patients engrafted on leukocytes (median day for recovery to 10(9)/L: day 30), patients with ALL recovered faster than patients with ANL (median day 19 v 34). Similarly, recovery of platelets to 50.10(9)/L occurred sooner in patients with ALL (median day 67, range day 23 through 90) whereas three patients with acute nonlymphoblastic leukemia (ANLL) in group 2 had to be supported with platelet transfusions for more than one year. In group 1, six patients had recurrent tumor within six months; three patients died from toxicity with no evidence of tumor. Two patients are still disease-free with a short follow-up (nine and ten months). In group 2, two patients died from toxicity with no evidence of leukemia three and 16 months post-ABMT. One patient with a M5 ANLL and one patient with ALL relapsed at six and 15 months, respectively. Nine patients have remained in CR or are disease-free with a median follow-up of 22 months.(ABSTRACT TRUNCATED AT 400 WORDS)

Expression of blood group antigens including HLA markers in human adult liver

The localisation of the principal blood group antigens has been studied in human liver. These blood group antigens included the erythrocyte antigens and the antigen of the major histocompatibility complex. This study was performed by the indirect immunofluorescence technique using polyclonal antibodies of human or animal origin and monoclonal antibodies from hybridomas. This study has shown that the normal hepatocyte is lacking in blood group antigens. On the contrary, the biliary cell was rich in antigenic markers: the main antigens expressed were Lewis, Pr, HLA-A and B antigens. In Kupffer cells, only i and HLA-DR antigens were clearly expressed. The endothelial cells of blood vessels mainly show A, B, H, HLA-A and B antigens; HLA-DR and Pr are slightly expressed. HLA-DR antigens were more strongly expressed on veins than on arteries. Dendritic cells have been identified in the portal space of human liver. They bore i and HLA-DR antigens.

[Diagnostic and therapeutic use of human anti-D (Rho) monoclonal antibodies. Evaluation and perspectives]

Human monoclonal antibodies will be essential in medicine. They are valuable tools for biological diagnosis and therapeutics. Our model, human monoclonal antibodies directed against the Rhesus D antigen can be used for the determination of the Rhesus D phenotype and for the suppression of Rh(D) immunisation in women. These new products require new procedures of preparation, new regulations for the quality controls, which will be discussed in this paper.

HLA antigens on peripheral red blood cells: analysis by flow cytofluorometry using monoclonal antibodies

The presence of HLA (class I) determinants on red blood cells was found in 15% of individuals of the French population. This percentage varies considerably from one geographical region to another in the world. The red blood cells (RBC) that express class I determinants also express beta 2 microglobulin but not HLA-DR antigens. This phenomenon does not appear to be linked to the erythrocyte phenotype nor to the HLA phenotype of the subject. Cytofluorometry analysis allowed us to establish that the large individual variations in the expression of the HLA antigens on RBC are related mainly to the percentage of positive cells but not to the fluorescence intensity of each cell. A comparative study between platelets and red blood cells showed that the expression (i.e. antigen density) of HLA class I determinants is weaker on red cell membrane.