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Subclasses of warm autoantibody IgG in patients with autoimmune hemolytic anemia and their clinical implications.

OBJECTIVE: To explore the mechanism of autoimmune hemolysis and establish a more sensitive test for autoimmune hemolytic anemia (AIHA). METHODS: IgG subclasses were tested in 40 patients with idiopathic or secondary AIHA by Coombs test with monoclonal antibodies. Hb, TBil, RC and FHb, as hemolytic parameters, were used to analyze the clinical implications of subclasses of AIHA warm autoantibody IgG. RESULTS: In most patients IgG incomplete warm autoantibody was IgG1 (27 patients), but IgG3 (20 patients), rarely IgG2 (14 patients) and IgG4 (9 patients) also occurred. Three groups were analyzed: Group A included 20 patients with IgG3; Group B included 14 patients with IgG1 bit without IgG3; Group C included 6 patients without IgG1 and IgG3. There were significant differences (P < 0.01) between groups in Hb, TBil, RC and FHb. Moreover, we also found that the sensitivity of Coombs test with polyclonal antiserums was 90.0%, while that of Coombs test with monoclonal antibodies was 97.5%. The effect of treatment was worst in patients with positive IgG3 autoantibody, whose hemolysis recurred frequently. CONCLUSION: IgG3 autoantibody was the most effective in bringing about red cell destruction, IgG1 autoantibody was less effective, IgG2 even less, whereas IgG4 autoantibody was shown to hardly affect red cell survival. Coombs test with monoclonal antibodies was more sensitive than that with polyclonal antiserums. Patients' respondence to treatment correlated with the type of IgG subclasses.

Adult↗

An immunohematological study of chronic copper toxicity in sheep.

Direct and indirect Coombs tests were performed on six experimentally chronic copper poisoned sheep and on two control sheep. Initially, all sheep were direct Coombs test negative and five of six experimental and one of two control sheep were indirect Coombs test positive. During intoxication, five of six experimental sheep became direct Coombs test positive while controls remained negative. Eluates, prepared from the red cells of three experimental sheep, sensitized normal sheep red cells, as measured by the indirect Coombs test. Similarly prepared eluates from control sheep were negative.

Animals↗

Isotype-specific antibodies in horses and dogs with immune-mediated hemolytic anemia.

Classes of antibody bound to erythrocytes were determined using direct immunofluorescence (DIF) flow cytometry in 3 horses and 12 dogs with immune-mediated hemolytic anemia (IMHA). Background levels of antibody binding were determined in samples from 12 horses and 12 dogs that were free of clinical disease. The range of nonspecific binding of a fluorescein isothiocyanate (FITC)-conjugated goat anti-equine immunoglobulin G (IgG) was 19.9-36.7%, but was eliminated by the use of the F(ab')2 fragment of FITC-conjugated goat anti-equine IgG. Background binding by other class-specific antibodies to equine and canine erythrocytes was negligible. The DIF results were compared to the direct antiglobulin (Coombs') test in 5 horses and 20 dogs with anemia. The former assay was more sensitive in dogs with IMHA than was the Coombs' test (100% versus 58%). In contrast, the Coombs' test had better specificity than the DIF assay (100% versus 87.5%, respectively). Using clinical parameters or response to therapy as the comparison, the positive and negative predictive values for the DIF test were 92% and 100% compared to the values of the Coombs' test of 100% and 62%. The DIF assay detected low levels of cells bound with antibody (<30%) in 5 dogs that were Coombs' test-negative. For both species, performance of the DIF test was independent of the prozone effect. Five dogs with IMHA had IgG and IgM on erythrocytes, 5 had IgG, and 2 had IgM. Three horses had surface-bound IgG, including a horse with suspected penicillin-induced IMHA, a foal with neonatal isoerythrolysis, and a foal with clostridial septicemia. The DIF method was valuable in monitoring the response to therapy in the foal with neonatal isoerythrolysis.

Anemia, Hemolytic, Autoimmune↗

[Category, quantity and clinical significance of autoantibodies on bone marrow hematopoietic cells in patients with immunorelated cytopenia].

OBJECTIVES: To explore the category, quantity and clinical significance of autoantibodies on bone marrow hematopoietic cells in patients with immunorelated cytopenia and evaluate the sensitivity of direct antiglobulin reaction (Coombs test ) of bone marrow mononuclear cells (BMMNC). METHODS: The category and the positive rate of autoantibodies on bone marrow hematopoietic stem cells, nucleated erythrocytes, granulocytes in 32 patients with uncertain immunorelated cytopenia were investigated by using BMMNC-Coombs test and double immunofluorescence flow cytometry. RESULTS: The positive rate of autoantibodies on bone marrow hematopoietic cells tested by flow cytometry was 90.63% which was higher than that by BMMNC-Coombs test (50.0%) (p < 0.05). In 29 positive cases, IgG autoantibody accounted for 6.90%, IgM13.8%, IgG+IgA 3.4%, IgG+IgM 31.0%, and IgG+IgM+IgA 44.8%. Of the 29 Patients, 25 (86.2%) with IgG autoantibody, 26 (89.7%) with IgM and 14 (48.3%) with IgA. The patients with IgG autoantibody alone had the lowest hemoglobin levels, and those with IgM autoantibody might have intravascular hemolytic findings. The response time of patients with IgG and IgG+IgM was shorter than that of the other patients. 91.3% of the patients had autoantibodies on bone marrow hematopoietic stem cells and showed pancytopenia, and 50% of the patients had autoantibodies on nucleated erythrocytes and granulocytes. Eleven of 13 patients with negative BMMNC-Coombs tests had autoantibodies on bone marrow hematopoietic stem cells detected by FACS. There was no significant difference of the quantities of the three categories of autoantibodies of nucleated erythrocytes and stem cells. The quantities of IgA on granulocytes were lower than that of IgG and IgM. There was no significant difference between IgG and IgM on granulocytes. The quantity of IgA on hematopoietic stem cells was significantly higher than that on nucleated erythrocytes or granulocytes. CONCLUSIONS: The sensitivity of double immunofluorescence flow cytometry assay was higher than that of BMMNC-Coombs test for detecting autoantibodies. In immunorelated cytopenia patients, the predominant autoantibody was IgM which could cause intravascular hemolysis, and the second one was IgG which could cause severe anemia. Most immunorelated cytopenia patients had autoantibodies on hematopoietic stem cells and showed pancytopenia. IgA was more easily seen on the hematopoietic stem cells.

Adolescent↗

[Haemolytic disease of the newborn--from a mother with anti-Kell, anti-E and anti-Vel anti-erythrocyte alloantibodies].

A grave form of HDN (haemolytic disease of the new-born) is described in female twins, caused by Kell, E and Vel isoimmunisation. The weakly vital and anaemic new-born babies were hospitalised with signs of respiratory distress on the first day of their life after the delivery by Caesarean section in the 38 (th) week of pregnancy in the General Hospital Dubrovnik. Already during the first hours of their life jaundice developed with a high bilirubin level for their age. The direct Coombs' test on the twins and the indirect Coombs' test on the mother were positive. Immuno-haematological analysis proved the presence of anti-Kell, anti-E and the very rare anti-Vel antibodies in the mother's serum and in the plasma of both twins. We had no possibility to obtain appropriate blood for the indicated exsanguine transfusion because cross-probes with the accessible blood samples were positive. Up to the fourteenth day of life the anaemia deepened and was aggravated in one twin, the Kell positive one (phenotype CcDEe,Kk) in relation to the other, the Kell negative (phenotype CcDEe,kk) twin. The recovery of the female twins started on the 15 (th) day of life, after the transfusion of blood (phenotype: 0,ccddee, Vel negative, Kel negative), received from the bank of rare blood groups in London. This is the first described case of haemolytic disease of the new-born caused by antibodies on the antigen Kell, E and Vel. The low frequency of immunisation with rare antigens such as Kell, E and Vel, does not exclude the possibility of the occurrence of grave forms of haemolytic disease. All pregnant women with a positive indirect Coombs' test should be further immuno-haematologically tested in order to identify the antibodies type so that the treatment of the new-borns could be commenced in time.

Blood Transfusion↗

Aspects of tolerability of centrally acting antihypertensive drugs.

Traditional centrally acting antihypertensives have been associated with a high incidence of adverse effects and are no longer recommended as first-line therapy. The newer imidazoline receptor agonists must overcome this reputation if they are to gain recognition as potential first-line agents for hypertension. Methyldopa, a centrally acting alpha(2)-agonist, is characterized by a number of serious adverse reactions that limit its use. Although unpredictable idiosyncratic or hypersensitivity reactions are uncommon, these include hepatitis, myocarditis, and hemolytic anaemia. Less serious problems such as abnormal liver function tests, positive Coombs test, drug-induced fever, and pancreatitis also occur. Central side effects include drowsiness, fatigue, lethargy, sedation, depression, psychotic reactions, nasal stuffiness, impotence, and exacerbation of Parkinsonism. In hypertensive men, methyldopa is less well tolerated than either captopril or propranolol, and up to 20% of patients discontinue therapy because of adverse effects. Clonidine acts primarily as an alpha(2)-agonist but also acts as an agonist at imidazoline receptors in the rostroventrolateral medulla. It is equipotent to most other antihypertensives but is considerably less well-tolerated in comparative trials. The principal adverse effects of clonidine are drowsiness, sedation, lethargy and dry mouth. Reserpine acts primarily by depleting central catecholamine neurotransmitter stores. It was very extensively used in early hypertension trials, but its central side effects of sedation, nasal stuffiness, and severe depression are now considered so undesirable that the drug is seldom prescribed. The imidazoline (I1) agonists moxonidine and rilmenidine act selectively and have very little central alpha(2)-agonist activity. In comparative studies against placebo and other reference antihypertensives, the only adverse effect consistently associated with these drugs was dry mouth (approximate placebo-corrected incidence 10%). Sedation was not pronounced. Withdrawal syndromes are complex pathophysiologic processes and occur with a variety of antihypertensive drugs. Cessation of therapy with clonidine and, to a lesser extent, methyldopa may result in a severe withdrawal syndrome characterized by restlessness, sweating, anxiety, tremor, palpitations, and headache. There may be a rapid rise in blood pressure, often with a true "rebound" to higher than pretreatment levels. Plasma and urinary catecholamine levels are increased, and fatalities have been reported. It is important to stress that such a syndrome has not been recorded, in animal or human studies, with either moxonidine or rilmenidine.

Antihypertensive Agents↗

Evaluation of a new immunocapture test for the diagnosis of ovine brucellosis caused by Brucella melitensis.

A new immunocapture technique has been applied to the diagnosis of ovine brucellosis under experimental conditions. The tests were made on a serum bank derived from both young and adult ewes vaccinated conjunctivally with the Rev 1 strain at a dose of 10(8) to 10(9) colony-forming units. Adult ewes were infected experimentally two-and-a-half years after they had been vaccinated and the results were compared with an unvaccinated control group. The condition of each animal in terms of infection with Brucella melitensis was determined by clinical and bacteriological investigations. The development of the immune response was compared by the rose bengal test, the complement fixation test, the Coombs' test and the immunocapture technique for 180 days after the vaccination and for 410 days after the experimental infection, that is, the two following gestations. The results suggest that the new technique is more specific in animals vaccinated conjunctivally, regardless of their age when they were vaccinated. After the experimental infection, significantly (P < 0.05) fewer of the vaccinated sheep which were free of clinical signs and were not excreting B melitensis reacted positively to the test.

Aging↗

The serological investigation of red cell incompatible transfusion reactions.

The hospital blood bank plays a key role in the diagnosis of acute transfusion reactions involving red cell incompatibility. This paper discusses the interpretation of the serological tests performed by the laboratory. Because red cell incompatible transfusion reactions occur so infrequently it is difficult to accumulate practical experience in their laboratory presentation and this paper describes several of the pitfalls that may be encountered when laboratory findings deviate from classical descriptions. These include the absence of a positive direct antiglobulin test (Coombs) or an incompatible crossmatch, the absence of any apparent discrepancy between the pre- and post-transfusion specimens in cases of ABO incompatibility, the differentiation of auto-immune haemolytic anaemia from delayed transfusion reactions and the assessment of the clinical significance of any blood group antibodies that may be detected.

ABO Blood-Group System↗

Auto-immune hemolytic anemia in two horses.

Two cases of Auto-immune hemolytic anemia (AHA) in the horse are described. The pathogenesis of AHA in man is related to the findings in the horses. Besides from routine hematological and biochemical investigations specific data were obtained from the erythrocyte osmotic fragility test, the Coombs test, the serum haptoglobulin level and the cold agglutinin test. The first patient, a six month old Dutch standardbred colt, probably suffered from an acute attack of cold-induced hemoglobinuria with severe anemia and acronecrosis of the tops of both ears and of several parts of the skin that had been in close contact with the cold floor. The second patient, a nine years old Friesian mare, showed a type of AHA resembling the acute hemolyte type of cold agglutinin disease in man. This patient had a clear septicemic picture, extensive bacteriological examination, however, was negative.

Adrenal Cortex Hormones↗

[Dot immunoassay with colloidal silver particles as a marker of specific antigen for testing human sera for brucellosis].

Whether the dot immunoassay is suitable for the detection of Brucella antibodies in human sera by using a colloidal silver-labeled Brucella specific antigen as a diagnostic tool is assessed. The antigen was the B. abortus 19BA protein polysaccharide complex isolated by Brucella acetic acid hydrolysis. The dot immunoassay is easy-to-use, cost-effective, highly sensitive, and therefore of more informative value in detecting Brucella antigens than routine serological tests (Huddleson test, Wright agglutination test, passive hemagglutination test, long-term complement fixation test, and Coombs test). It requires no use of expensive equipment and reagents.

Antibodies, Bacterial↗

[Chronic myelomonocytic leukemia (CMMoL) with systemic lymph node swelling and paroxysmal nocturnal hemoglobinuria (PNH)-like complication].

A 37-year-old male was diagnosed as having chronic myelomonocytic leukemia (CMMoL) with chief complaint of systemic lymph node swelling. On admission, his peripheral blood revealed mild anemia and mild thrombocytopenia with giant platelets, and monocytosis (1480/microliters). NAP score was low. Serum lysozyme increased. The bone marrow showed normal cellularity consisting of 4% myeloblasts and 14.4% promyelocytes, and a few myeloid cells were positive for double staining by alpha-naphthyl butyrate and naphthol ASD chloroacetate esterase. Biopsied specimens of the cervical lymph node showed infiltration of monocytoid cells, which were positive for lysozyme staining, into interfollicular tissue. As for chromosome variation, 21 large satellite was observed in all dividing cells from his bone marrow and peripheral blood. Furthermore, hemolytic anemia with hemoglobinuria developed during his course. Sugar water test was positive, but Ham test negative. Coombs test and Donath-Landsteiner reaction were negative. Abnormal hemoglobin, spherocyte and fragmentation were not found. Hemolysis disappeared about two months later. However, blastic crisis appeared and he died. We showed a case of CMMoL with 21 large satellite and paroxysmal nocturnal hemoglobinuria (PNH)-like complication. Satellite have usually been reported as asymptomatic, and thus this chromosome variant and CMMoL may have been coincidentally observed.

Adult↗

Severe Coombs'-negative autoimmune hemolytic anemia in a kidney transplant patient.

BACKGROUND/AIM: Few cases are found in the literature regarding autoimmune hemolytic anemia which is Coombs' test positive in kidney transplant patients, although hemolytic uremic syndrome due to cyclosporin and FK506 has been well described. In the following, we describe a case of severe life-threatening Coombs' test negative autoimmune hemolytic anemia after kidney transplantation. METHODS: Soon after undergoing renal transplantation, the patient presented with hemolytic anemia. Kidney biopsy, routine Coombs' test, gel filtration and flow-cytometric assay were undertaken. RESULTS: Kidney biopsy ruled out hemolytic uremic syndrome; although Coombs' test and gel filtration assay were negative, flow cytometry revealed circulating antierythrocytic autoantibodies. CONCLUSIONS: Our findings indicate that flow cytometry may be an efficient method in the diagnosis of hemolysis of unknown origin in transplant patients. We further hypothesize that the underlying mechanism of autoimmune hemolytic anemia is related to the passenger B lymphocytes in the graft.

Anemia, Hemolytic, Autoimmune↗