Autoantibodies similar to antidifferentiation ones in immune neutropenias

Abstract

Two groups were distinguished among patients with autoimmune neutropenia with manifest antigranulocytic antibodies. One group consisted of patients whose sera reacted with all forms of leukocytes (granulocytes, monocytes, T and B lymphocytes), like CD45 monoclonal antibodies. Sera of patients from the other group reacted only with polymorphonuclear leukocytes and monocytes, similarly as CD13 monoclonal antibodies. Immunologically distinguished types of neutropenia were characterized by a typical chronic or acute clinical course. Key Words: cluster of differentiation antigens; antigranulocytic antibodies; immune neutropeniasImmune neutropenias are little studied serious diseases. Antineutrophilic antibodies detected in patients with neutropenia have not been characterized in sufficient detail [4,5,10]. Recent studies with monoclonal antibodies (Table 1) MATERIALS AND METHODSSera of 15 patients with immune neutropenia aged 1-61 years were examined. Clinically the disease was characterized by acute or chronic neutropenia with or without concomitant bacterial or viral infections or local inflammations. Sera of all patients contained granulocytotoxic antibodies. In the majority of sera these antibodies were detected in titers 1:16-1:128. In three patients the titer of antibodies was no higher than 1:8.Complement-dependent cytotoxic test was the principal method of investigation [8,10]. Serum (1 lal) was pipetted into 60-weU plates under Vaseline oil, an equal volume of suspension with cell concentration of 3000-4000 eells/mm 3 was added, and the mixture was incubated for 1 h with polymorphonuclear leukocytes and monocytes at 4~ and with B and T lymphocytes at 18"C. Then 5 ~tl complement (fresh or lyophilized rabbit serum) was added into each well.The plates were incubated for 1.5 h at ambient temperature, after which the contents of the wells was then discarded and 1 rtl 1% Trypan Blue was added in each well. After 5 rain, the reaction was assessed by counting dead and live ceils. The result was considered positive if at least 50% cells were dead (2 points); no more than 10% cells were dead in control wells with nonimmune AB(IV) serum (0 points).

Immune cytopenias and some associated problems of immunohematology

“…Complement-dependent cytotoxic antibodies reacting with allogeneic and autologous polymorphonuclear leukocytes are strongly expressed in such patients, particularly in children. Our studies showed that in contrast to aUoimmune neutropenias of newborns, the sera of patients with autoimmune neutropenias react with the leukocytes of the mother, father, and nonrelatives [14,41]. A high inverse correlation was noted between the titer of granulocytotoxic antibodies and the absolute count of polymorphonuclear leukocytes in the patient's blood.…”

“…A high inverse correlation was noted between the titer of granulocytotoxic antibodies and the absolute count of polymorphonuclear leukocytes in the patient's blood. These data indicate that autosensitization to antibodies of polymorphonuclear leukocytes is caused not only by drug therapy, playing the role of a peculiar adjuvant, but by certain genetic prerequisites as well [14]. The fact that one of the parents of a child with immune neutropenia often had autogranulocytic antibodies is one more piece of evidence in favor of this hypothesis.…”

Transformation of blood groups B (III) and A (II) into AB (IV) after bone marrow transplantation from HLA identical sibs with groups A (II) and B (III)

“…In some cases the recipient's erythrocytes are completely replaced by donor's antigenic phenotype, involving the alteration of recipient's blood group. In other cases both autologous erythrocytes and the donor phenotype erythrocytes circulate in the organism [1,5].…”