Biomedical subjects

G Eiber

Publications and source records attributed to G Eiber.

4 recordsLinked to original sources

PubMed1997

Lack of relation of granulocyte antibodies (antineutrophil antibodies) to neutropenia in children with human immunodeficiency virus infection.

BACKGROUND: Neutropenia in children and adults with HIV infection is frequently observed, perhaps as a result of impaired myelopoiesis, drug myelotoxicity, immune destruction or opportunistic infection. The presence of antineutrophil antibodies (granulocyte antibodies) has been associated with severe neutropenia in some reports but not in others, and such antibody assays can be confounded by the presence of immune complexes and HLA antibodies. METHODS: To determine both the prevalence of granulocyte antibodies in children with HIV infection and whether such antibodies were related to neutropenia, we screened the sera of 30 HIV-infected children by performing granulocyte immunofluorescence, granulocyte agglutination and lymphocytotoxic anti-HLA antibody assays. Reactivity was graded by a standard numeric score calculated per number of reactive cells. RESULTS: Of 26 evaluable sera, 16 (62%) had granulocyte antibodies, 6 (23%) had HLA antibodies and 4 (15%) had neither. There was no correlation between presence of granulocyte antibodies and degree of neutropenia. CONCLUSIONS: We conclude that granulocyte antibodies are highly prevalent in children with HIV infection but do not correlate with the degree of neutropenia. Antineutrophil antibody determination as currently performed does not appear to be useful in the evaluation of the HIV-infected neutropenic child.

Adolescent↗

PubMed1994

Identification of a new white cell antigen.

BACKGROUND: Antibodies to white cell antigens can cause alloimmune neonatal neutropenia, autoimmune neutropenia, and transfusion reactions. CASE REPORT: A full-term male infant developed a skin infection and was found to be neutropenic on his fourth day of life. He had a transient increase in his neutrophil count after treatment with intravenous immunoglobulin, but his neutrophil count was not consistently normal until he was 6 weeks old. Serum from the baby's mother reacted in a granulocyte immunofluorescence assay but not in a granulocyte agglutination assay. The mother's serum was tested in the granulocyte immunofluorescence assay against neutrophils from 103 healthy, unrelated people, and it reacted with cells from 66 percent of those people. The expression of SL correlated weakly with the expression of NA1 (r = 0.23; p = 0.02) and 5a (r = 0.20; p = 0.05) antigens. SL antigen expression on neutrophils was not associated with the expression of NA2, NB1, NB2, NC1, 5b, 9a, or Mart. The expression of SL on neutrophils from members of an extended family was analyzed, and the antigen was found to be inherited in an autosomal-dominant manner. Anti-SL also reacted with T-lymphocytes in a flow cytometry assay but did not react with red cells or platelets. No lymphocytotoxic antibodies were detected in the mother's sera. The anti-SL was tested against neutrophils in an immunoprecipitation and immunoblotting assay, but no molecules were identified. The neutrophil-specific antigens NA are located on Fc gamma receptor III (CD16). To determine if the SL antigen was also located on Fc gamma receptor III, anti-SL was also tested in a monoclonal antibody immobilization of granulocyte antigens assay. Anti-SL did not react with molecules recognized by CD16 monoclonal antibodies. CONCLUSION: A new white cell antigen SL, with a frequency of 66 percent, was identified on neutrophils and T-lymphocytes as a result of the evaluation of a case of neonatal alloimmune neutropenia. The molecule bearing the SL antigen was not identified in immunoblotting, immunoprecipitation, or monoclonal antibody immobilization of granulocyte antigens assays.

Adult↗

PubMedDate not supplied

Characterization of the neutrophil molecules identified by quinine-dependent antibodies from two patients.

BACKGROUND: Two patients with episodic pancytopenia and renal failure associated with quinine (Qn) ingestion were previously found to have Qn-dependent antibodies that reacted with red cells, platelets, and neutrophils. The purpose of these studies was to characterize the neutrophil antigens recognized by Qn-dependent antibodies from these two patients. STUDY DESIGN AND METHODS: The neutrophil molecules recognized by the Qn-dependent antibodies in the sera from the two patients were analyzed by immunoprecipitation using 125I-labeled neutrophils. Neutrophils from 13 different donors were tested. RESULTS: The Qn-dependent antibodies from Patient 1 immunoprecipitated a 60-kDa molecule on neutrophils from seven donors and an 85-kDa molecule on neutrophils from three donors. The Qn-dependent antibodies from Patient 2 reacted with a 32-kDa molecule on neutrophils from 5 donors, a 60-kDa molecule on neutrophils from 9 donors, and an 85-kDa molecule on neutrophils from 10 donors. Neutrophil-specific antigen NB1 is also located on a 60-kDa glycoprotein (GP). While the antibody in serum from Patient 1 did not show specificity for NB1, the antibody from Patient 2 detected the 60-kDa molecule on NB1-positive neutrophils from 9 of 11 donors tested and did not detect the 60-kDa molecule on NB1-negative neutrophils from 2 donors. In a monoclonal antibody immobilization of granulocyte antigens assay, the Qn-dependent antibody from both patients reacted with the 60-kDa molecule carrying NB1. The Qn-dependent antibody from a third patient, Patient 3, was previously found to react with an 85-kDa GP and the 60-kDa NB1 GP. To determine if the Qn-dependent antibodies from Patients 2 and 3 recognized the same 85-kDa GP, neutrophils were treated with serum from Patient 3 plus Qn to remove the 85-kDa GP. Then, serum from Patient 2 plus Qn no longer immunoprecipitated the 85-kDa GP. CONCLUSION: The antigens recognized by Qn-dependent neutrophil antibodies were located on molecules of 85, 60, and 32 kDa. Qn-dependent antibodies from two patients reacted with the same 85-kDa GP and those from three patients reacted with the same 60-kDa GP. The 60-kDa molecule recognized by the Qn-dependent antibodies carried the NB1 antigen.

Antibodies↗

PubMedDate not supplied

Alloimmunization after granulocyte transfusions.

BACKGROUND: Although granulocyte transfusions are recommended for neutropenic patients with bacterial infections that are unresponsive to antibiotic therapy, the presence of white cell (WBC) antibodies in the recipient can render these transfusions ineffective. STUDY DESIGN AND METHODS: A 25-year-old man with chronic granulomatous disease experienced a pulmonary transfusion reaction while receiving granulocyte transfusions, and he was found to be immunized to neutrophil antigen NA2. A retrospective study of alloimmunization to HLA and neutrophil antigens in 18 patients with chronic granulomatous disease who had also received repeated granulocyte transfusions was then performed. Sera were tested in lymphocytotoxicity, granulocyte agglutination, granulocyte immunofluorescence, monoclonal antibody immonobilization of granulocyte antigen, and immunoprecipitation assays. RESULTS: After the granulocyte transfusions, sera from 14 of the 18 patients contained WBC antibodies. Seven sera samples reacted in the lymphocytotoxicity, granulocyte immunofluorescence, and granulocyte agglutination assays; seven reacted in the lymphocytotoxicity and granulocyte immunofluorescence assays but not the granulocyte agglutination assay, and four did not react. When the monoclonal antibody immobilization of granulocyte antigen assay was used, three sera samples reacted with Fc gamma receptor III, three with the 58- to 64-kDa protein carrying the neutrophil antigen NB1, one with CD11a, and one with CD18. Antibodies from three patients immunoprecipitated a neutrophil protein of 60 kDa. Overall, antibodies to neutrophil antigens other than HLA could be detected in sera from eight patients. Transfusion reactions occurred in 11 of the 14 individuals with WBC antibodies and in none of the 4 without antibodies. Seven pulmonary reactions occurred in patients with WBC antibodies. The patients with WBC antibodies were given significantly more granulocyte concentrates (78 +/- 65 vs. 29 +/- 15 units, p < 0.05). CONCLUSION: Recipients of granulocyte transfusions often become alloimmunized. Screening for WBC antibodies periodically during transfusions, after adverse reactions, or before subsequent transfusions is indicated. If WBC antibodies are present, no further granulocyte transfusions should be given unless the granulocytes are collected from HLA- and/or neutrophil antigen-compatible donors.

Adolescent↗