Diminished presentation of complement regulatory protein CD55 on red blood cells from patients with hereditary haemolytic anaemias.

INTRODUCTION: Hereditary haemolytic anaemias (HHA) encompass a heterogeneous group of anaemias characterized by decreased red blood cell survival. The aim of this study was to evaluate the status of red blood cell (RBC) surface molecules known or previously proposed to participate in preventing premature RBC clearance, analysing erythrocytes from patients with two types of HHA: hereditary spherocytosis (HS) and microcytosis. MATERIAL/METHODS: Relative binding of five monoclonal antibodies (mAbs), anti-CD55, anti-CD59, anti-CD44, anti-CD47 and anti-CD58, was evaluated in erythrocytes of patients with HS and hereditary microcytosis, using flow cytometry. The amount of CD55 protein was assessed by semi-quantitative Western blots densitometry analysis. RESULTS: The majority of both HS and microcytic patients demonstrated significant reduction of anti-CD55 binding by erythrocytes (average 23% and 19%, respectively, P < .001), with no concomitant anti-CD59-binding deficiency. Anti-CD44, anti-CD47 and anti-CD58 binding was within the healthy control range or was slightly decreased. CONCLUSIONS: This study provides evidence supporting the presence of erythrocytes deficient in CD55 presentation in HS and hereditary microcytosis. Moreover, deficiency of CD55 antigen presentation on RBC does not correlate with the amount of CD55 in RBC membrane. Further studies using molecular techniques will clarify the exact participation of CD55 deficiency in premature RBC clearance in HHA.

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.

Short report: erythrocyte membranes from a patient with congenital dyserythropoietic anaemia type I (CDA-I) show identical, although less pronounced, glycoconjugate abnormalities to those from patients with CDA-II (HEMPAS).

Congenital dyserythropoietic anaemias (CDAs) are rare hereditary disorders characterized by ineffective erythropoiesis and multinuclearity of erythroblasts. Three main types of the disease have been described. Glycoconjugate abnormalities in erythrocyte membrane glycoconjugates, consisting of hypoglycosylation of band 3 and accumulation of certain glycosphingolipids including lactotriaosylceramide, neolactotriaosylceramide and polyglycosylceramides, have been described only in patients with CDA type II (CDA-II). We report on identical, although less pronounced, abnormalities in erythrocyte glycoconjugates from a patient with CDA-I. A low degree of hypoglycosylation of band 3 in our patient with CDA-I suggests that hypoglycosylation is not a cause, but, most probably, a consequence of dyserythropoiesis.

Incidence and treatment of hepatitis C virus infection in children with haemophilia in Poland.

In 80% of children with haemophilia treated in our department, screening tests showed the presence of antibodies against the hepatitis C virus (HCV). HCV RNA was detected in serum in 41% of cases. In 20% of cases there were periodic increases in the level of alanine aminotransferase (ALT) activity, and in these cases liver biopsy was performed after factor concentrate replacement. No haemorrhagic complications or pain complaints were reported either during the biopsy or immediately afterwards. In all cases histopathological examination revealed chronic hepatitis type C - chronic mild hepatitis and chronic minimal hepatitis. Eight boys were treated with interferon (INF) alpha. In two cases this therapy was successful. No HCV RNA was detected in serum and transaminase activity was normal during the year following interferon treatment.

[Influenza vaccination of children with hemophilia]. / Szczepienia przeciw grypie dzieci chorych na hemofilie.

51 haemophilic children aged from 7 to 16 years was vaccinated against influenza in Paediatric Department of Haematology and Oncology in November and December of 1993. Each dose of subunit vaccine manufactured by Wyeth-USA, contained 15 micrograms of each haemagglutinin strains as recommended for the season. The antibody level was studied before and after influenza vaccination in vaccinated and control group as well. 5-time rise of geometric mean antibody titre was found for H1N1 and H3N2 antigens after vaccination of the children group. Slightly lower, 2.7-time rise of GMT was showed for HB haemagglutinin of influenza virus. There was no significant rise of GMT for any among three studied virus haemagglutinin.