Quantitation of red cell-bound IgG by an enzyme-linked antiglobulin test in the patients with warm-type autoimmune haemolytic anaemia

We have previously reported the evaluation of a gel-direct antiglobulin test and enzyme-linked antiglobulin test (ELAT) in the laboratory diagnosis of autoimmune haemolytic anaemia (AIHA). We now report our experience with quantitative ELAT performed on a large group of patients under long-term observation. The number of IgG molecules/red blood cell was determined in 658 blood samples from 268 randomly selected patients with warm-type AIHA. Eighty-six patients were tested every 2-4 weeks for several months. Laboratory signs of haemolysis were present in 65.7% of blood samples with a small amount of red cell-bound autoantibody (< 200 IgG molecules/red blood cell) and in 70.4% of blood samples with moderately coated red blood cells (200-1000 molecules/red blood cell). Haemolysis was demonstrated in 87.9% samples with > 1000 IgG molecules/red blood cell, which were predominantly IgG3 and C3 complement, the qualitative factors that may increase haemolysis. In 79% of periodically tested patients, the number of IgG autoantibody molecules/red blood cell decreased and this correlated with the improvement of haemolysis parameters. The number of IgG molecules varied in 21% of AIHAs and was associated with poor prognosis.

B cells CD19+ in patients with B-cell chronic lymphocytic leukaemia and autoimmune haemolytic anaemia

The study presents results of B and T lymphocytes population analysis in patients with chronic lymphocytic leukaemia B cells and autoimmune haemolytic anaemia (CLL-B + AIHA). We evaluated the following groups of patients: (1) with newly recognized CLL-B and co-existent AIHA (untreated), (2) after short-term treatment with corticosteroids, (3) after treatment with chemotherapy and corticosteroids. The control groups were made of patients with CLL-B without AIHA. The populations of lymphocytes and determination of cells immunophenotype were performed by means of flow cytometry. The analysed data were obtained from 25 patients. The untreated patients with CLL-B + AIHA presented significantly more numerous population of neoplastic cells CD19+ CD5+ in comparison with patients without AIHA. The patients with AIHA showed a reduced percentage of B CD19+ CD22+ cells in comparison with those without AIHA. Untreated patients with AIHA or after a short-term corticosteroid treatment showed a higher ratio of the number of CD19+ CD5+ cells to the number of T CD4+ and T CD8+ lymphocytes than CLL-B patients without AIHA. It can be presumed that the differences found may be related to the pathogenesis of the autoimmune haemolysis syndrome in patients with CLL-B.

Glycoconjugate abnormalities in patients with congenital dyserythropoietic anaemia type I, II and III

Congenital dyserythropoietic anaemia type II (CDA II) is well known for glycosylation abnormalities affecting erythrocyte membrane glycoconjugates that encompass hypoglycosylation of band 3 glycoprotein and accumulation of glycosphingolipids: lactotriaosylceramides, neolactotriaosylceramide and polyglycosylceramides. These abnormalities were not observed in erythrocytes from patients with CDA of either type I or III. Recently, however, we have described a CDA type I patient in Poland with identical, though less pronounced, glycoconjugate abnormalities to those observed in patients with CDA type II. The abnormalities included partial unglycosylation of O-linked glycosylation sites in glycophorin A. These abnormalities are now reported in three Bedouin patients from Israel with CDA type I. In addition, the erythrocyte membranes of these patients exhibited highly increased globotetraosylceramide content. Glycoconjugate abnormalities were also present in erythrocyte membranes from three patients from Northern Sweden with CDA type III but they almost exclusively affected glycosphingolipids. In erythrocytes of all patients examined including one with CDA type II, polyglycosylceramides were significantly hypoglycosylated although, on a molar basis, their contents in erythrocyte membranes were increased. Thus, glycoconjugate abnormalities of varying intensity occur in erythrocyte membranes from all patients with CDA that were investigated.

Evaluation of the microcolumn technology for pretransfusion testing in multiple myeloma patients

OBJECTIVE

Microcolumn tests are useful for serological investigations, although because of their high sensitivity, false-positive results might be expected, e.g. in hypergammaglobulinemia. The aim of this study was to evaluate these tests in multiple myeloma.

METHODS

Pretransfusion testing was done in 80 patients with multiple myeloma using microcolumn and traditional tube tests.

RESULTS

All sera were negative in microcolumn indirect antiglobulin test and enzyme test, positive in 58% of samples in the enzyme tube test. The microcolumn direct antiglobulin test was positive in about 40% of samples but never in the tube direct antiglobulin test. This was not due to the presence of autoantibodies but to nonspecific binding of immunoglobulins related to their concentration in sera.

CONCLUSION

Microcolumn tests appeared to be useful for pretransfusion testing in multiple myeloma in spite of positive autocontrols.

Gel test application for IgG subclass detection in auto-immune haemolytic anaemia

BACKGROUND AND OBJECTIVES

Commercially available gel test microtubes are not available with antisera for the determination of IgG subclasses. The aim of this study was to adapt the gel technique for this purpose and apply it to the investigation of patients with autoimmune haemolytic anaemia (AIHA).

MATERIALS AND METHODS

We studied 66 red cell samples from 49 patients with AIHA of the warm-active IgG type. Standard serologic and haematologic methods were used. We adapted the DiaMed gel test by using IgG-subclass antisera.

RESULTS

We found the adapted test useful in determining the subclass of autoantibodies in eluates. We could identify the IgG subclass in all the AIHA patients, even those that were 'Coombs-negative', with less than 200 IgG molecules bound in vivo per red cell. Comparison of the gel test with the standard spin tube test and the microtiter plate test showed the superiority of the gel test, i.e., detection of IgG subclasses was much better than with the tube test and the results were more clearcut than those of the microplate test. The gel test is also the simplest and least time-consuming and permits a later reading of results. Application of the test in our 66 samples confirmed that IgG1 was the most frequent (96%). In 59% of the cases it was accompanied by IgG of other subclasses. Multiple subclasses were most common in the cases with stronger in vivo IgG red cell sensitization and severe haemolysis. Accompanying IgG3 was detected only in patients with obvious haemolysis.

CONCLUSION

The gel test is more sensitive than other procedures for the determination of IgG subclass and has the advantages of simplicity, rapidity, low cost, and stability of the agglutinates.