Rapid detection of antibodies to immunoglobulin A molecules by using the particle gel immunoassay

BACKGROUND AND OBJECTIVES

Antibodies to immunoglobulin A (IgA) molecules are thought to be frequently responsible for anaphylactic reactions in transfusion medicine, but practical tests for the detection of antibodies to IgA are not yet available.

MATERIAL AND METHODS

Red, high-density polystyrene beads were coated with purified IgA molecules and then used to test serum samples collected from unselected healthy blood donors (n = 105) and patients with common variable immunodeficiency and/or IgA deficiency (n = 44). For testing, the standard gel-agglutination technique (ID-Micro Typing System) was employed.

RESULTS

None of the normal serum samples were reactive with IgA-coated beads and samples from only 10 patients were positive (titre range 1 : 2 to 1 : 256). Only one out of all patients studied had a history of an anaphylactic reaction and this was related to the administration of Rh(D) prophylaxis (anti-D immunoglobulin). The beads did not show non-specific agglutination and could be used repeatedly for longer than 6 months. The results were reproducible in all patients tested.

CONCLUSION

The new test allows a specific and rapid detection of antibodies to IgA molecules. In order to evaluate the clinical relevance of the test, analysis is required of a wider range of antibodies that produce anaphylactic reactions.

Interleukin-6 is a major effector molecule of short-term G-CSF treatment inducing bone metabolism and an acute-phase response

OBJECTIVE

The biological steps leading to hematopoietic progenitor cell (HPC) mobilization from the bone marrow to the peripheral blood compartment during G-CSF treatment are still poorly defined. In this study, we investigated G-CSF-mediated secretion of cytokines as potential mediators.

MATERIALS AND METHODS

Plasma and urine samples from G-CSF-mobilized donors for HPC transplantation were collected before and during mobilization therapy. Interleukin-6 (IL-6), alkaline phosphatase (ALP), bone-specific ALP (bone ALP), C-reactive protein (CRP), lipopolysaccharide binding protein (LPB), CD34+ cells and urinary deoxypyridinoline (DPD) concentrations were measured and statistically correlated.

RESULTS

IL-6 was highly elevated at days 4 and 5 of G-CSF treatment. G-CSF administration led to elevation of IL-6 parallel to the appearance of CD34+ cells in the peripheral blood. Major metabolic changes such as high bone ALP plasma concentration and urinary excretion of deoxypyridinoline (DPD), indicating stimulation of bone metabolism, were observed. Elevated concentrations of CRP and LPB indicated an acute-phase response. Furthermore, CRP concentrations correlated significantly with the percentage of mobilized CD34+ cells.

CONCLUSION

Based on these findings, we propose IL-6 as a major physiological effector molecule of G-CSF treatment that induces bone metabolism and an acute-phase reaction along with mobilization of CD34+ cells in the peripheral blood. IL-6 may be responsible for osteopenia observed during short- and long-term G-CSF treatment. These observations may also have implications for G-CSF treatment of patients with plasmocytoma.

Management of the oral and maxillofacial surgery patient with thrombocytopenia

Patients with disorders of coagulation and bleeding can be among the most challenging surgical patients to manage. Intraoperative or postoperative bleeding can contribute to life-threatening complications in even the most "benign" surgical procedures. An adequate number and function of platelets play a critical role in the coagulation pathway. A thorough understanding of platelet physiology and platelet disorders is therefore essential in the management of the thrombocytopathic oral and maxillofacial surgery patient. A careful preoperative evaluation will help the surgeon treat these patients and help prevent potentially catastrophic intraoperative or postoperative bleeding.

Donor-derived alloantibodies and passenger lymphocyte syndrome in two of four patients who received different organs from the same donor

BACKGROUND

Reported here is the occurrence of RBC alloimmunization in two of four patients who received different organs from an immunized donor.

STUDY DESIGN AND METHODS

The donor, a 58-year-old woman, was group O D+, K-, and Fy(a-). Initially, her serum contained only a K antibody. After blood transfusion, a second antibody (anti-Fy(a)) could also be identified. The liver was given to a group O D+, K-, Fy(a+) patient; the pancreas and one kidney to a group O D+, K-, Fy(a+) patient; the heart to a group A D+, K-, Fy(a-) patient; and the other kidney to a group B D+, K-, Fy(a+) patient. RBC grouping and antibody screening were performed by standard techniques. Lymphoid microchimerism in the peripheral blood of the recipients was analyzed by flow cytometry and nested PCR.

RESULTS

None of the recipients had irregular RBC alloantibodies at the time of transplantation. After the transplant, anti-K became detectable in the serum of the liver recipient, and anti-Fy(a) could be eluted from the RBCs of the liver recipient and the pancreas-kidney recipient. The latter patient also developed mild hemolysis, and his Hb dropped to 8 g per dL on posttransplant Day 9. Donor-derived lymphocytes were detectable by flow cytometry in the peripheral blood of the liver recipient and the pancreas-kidney recipient until Days 8 and 63, respectively, whereas no lymphoid chimerism could be demonstrated in the heart recipient. PCR chimerism analyses were positive in all three recipients over the whole observation period of 97 postoperative days.

CONCLUSION

The amount of cotransplanted lymphoid tissue may correlate with the extent of peripheral lymphoid microchimerism and the antibody-formation capacity in solid organ transplantation.

Dipeptidyl peptidase IV (DPP IV, CD26) in patients with mental eating disorders

The notion that patients with eating disorders maintain a functional immunosurveillance in spite of severe malnutrition has attracted researchers for years. Dipeptidyl Peptidase IV (DPP IV), a serine protease with broad tissue distribution and known activity in serum, operates in the cascade of immune responses. Membrane-bound DPP IV expressed on lymphocytes, also known as the leukocyte antigen CD26, is considered to participate in T cell activation. We hypothesized that the activity of DPP IV in serum and expression of CD26 in lymphocytes may be altered in patients with eating disorders. Serum DPP IV activity and the number of CD26 (DPP IV)-positive peripheral blood lymphocytes were measured in 44 patients (anorexia nervosa (AN): n = 21, bulimia (B): n = 23) in four consecutive weekly analyses. The analysis of CD26-positive cells included the characterization of CD26-bright and CD26-dim positive subsets. Additionally, the expression of CD25 (IL-2 Receptor alpha chain) was evaluated to estimate the degree of T cell activation. The same analyses were carried out in healthy female volunteers (HC, n = 20). CD26-positive cells were reduced in patients as compared to healthy controls (mean 40.2% (AN) and 41.1% (B) vs. 47.4% (HC), p < 0.01), while the DPP IV activity in serum was elevated (mean 108.4 U/l (AN) and 91.1 U/l (B) vs. 80.3 U/l (HC), p < 0.01). The potential implications of changes in DPP IV expression and serum activity on--and beyond--immune function are discussed.

Beta-adrenergic stimulation of volume-sensitive chloride transport in lamprey erythrocytes

We measured the effects of a beta-adrenergic agonist, isoproterenol, on chloride transport and volume regulation of lamprey (Lampetra fluviatilis) erythrocytes in isotonic (288 mosm L(-1)) and hypotonic (192 mosm L(-1)) medium. Isoproterenol at a high concentration (10(-5) M) did not influence chloride transport in isotonic medium but markedly increased chloride fluxes in hypotonic conditions: unidirectional flux increased from 100 mmol kg dcw(-1) h(-1) in the absence to 350 mmol kg dcw(-1) h(-1) (dcw=dry cell weight) in the presence of isoproterenol. Simultaneously, the half-time for volume recovery decreased from 27 to 9 min. Isoproterenol caused an increase in cellular cyclic AMP (cAMP) concentration. The stimulation of chloride transport in hypotonic conditions could be induced by application of the permeable cAMP analogue, 8-bromo-cyclic AMP, suggesting that the effect of beta-adrenergic stimulation on chloride transport occurs downstream of cAMP production. As isoproterenol did not affect unidirectional rubidium fluxes in hypotonic conditions, the transport pathway influenced by beta-adrenergic stimulation is most likely the swelling-activated chloride channel. Because the beta-adrenergic agonist only influenced the transport in hypotonic conditions despite the fact that cAMP concentration also increased in isotonic conditions, the activation may involve a volume-dependent conformational change in the chloride channel.

Detection of germ-cell tumor cells in peripheral blood progenitor cell harvests: impact on clinical outcome

Our study was conducted to evaluate the impact of tumor cell contamination in peripheral blood progenitor cell (PBPC) harvests on the clinical outcome of patients with germ-cell tumors undergoing high-dose chemotherapy (HDCT) and autologous PBPC reinfusion. Samples of mononuclear cells from progenitor cell harvests of 57 patients with advanced or recurrent germ-cell tumors were retrospectively screened for contaminating tumor cells using immunocytochemical staining for cytokeratin filaments and reverse transcription-PCR (RT-PCR) testing for germ-cell alkaline phosphatase mRNA. The results were correlated to clinical prognostic variables as well as to the overall and event-free survival of these patients. Tumor cell contamination was detected in PBPC harvests of 16 of 57 enrolled patients (28%), and, among these, in 14 of 51 (27%) who underwent HDCT. The presence of contaminating tumor cells as detected by either immunocytochemical staining, RT-PCR, or both was strongly associated with a reduced overall survival (43% versus 71%, P = 0.0037) and event-free survival (0% versus 52%, P = 0.0005) after 1 year. In multivariate analysis, the demonstration of contaminating tumor cells had a higher predictive value for a poor event-free survival than other known prognostic variables. The presence of contaminating tumor cells in PBPC harvests of patients with germ-cell tumors seems to predict a poor overall and event-free survival in patients undergoing HDCT and autologous PBPC reinfusion.

Epidemiological and clinical aspects of hepatitis G virus infection in blood donors and immunocompromised recipients of HGV-contaminated blood

BACKGROUND AND OBJECTIVES

The infectiousness and clinical relevance of the newly discovered blood-borne Flaviviridae-like agent, termed hepatitis G virus (HGV), are not well understood.

MATERIALS AND METHODS

Twenty-three transfusion recipients of two HGV-affected long-term blood donors were studied for HGV genome and antibodies to the putative envelope 2 glycoprotein (anti-E2) of HGV. Nine recipients had nonhematological disorders and 14 suffered from severe hematological diseases and 7 of them received allogeneic bone marrow or blood stem cell transplantation. The molecular epidemiology of the observed HGV infection was studied by direct sequencing of parts of the 5'-noncoding region, NS3, and NS5 region of HGV in the 2 long-term donors and in their 6 recipients who became HGV RNA positive. Additionally, 549 individuals-homologous (n = 254) and autologous blood donors (n = 202), and medical staff (n = 89)--were investigated for the presence of HGV RNA.

RESULTS

HGV RNA in serum was found in 15 of the 23 (65%) transfusion recipients with known exposure of HGV-contaminated blood. Seven of the remaining 8 recipients showed only an anti-E2 response, indicating previous HGV infection with spontaneous clearance of the virus. In one recipient neither HGV RNA nor anti-E2 could be detected. Molecular evidence for HGV transmission by the 2 donors was found in 3 of the 6 recipients studied. The alanine aminotransferase levels were not significantly different in the HGV RNA positive and negative recipients, and none of the 23 recipients developed posttransfusion hepatitis. Persistent HGV infection was observed especially in recipients with severe hematological disorders or in those in whom intensive immunosuppressive treatment was necessary. Of the 549 individuals studied, 10 (1.8%) were healthy carriers of HGV RNA.

CONCLUSION

The persistence of transfusion-acquired HGV infection is not associated with acute or chronic hepatitis, but may be influenced by the recipient's underlying disease.

An extended lymphocytotoxicity test for patients treated with lymphocytotoxic antibodies

BACKGROUND AND OBJECTIVES

After organ transplantation, HLA antibodies (HLA-Ab) stimulated by transplant or transfusion are usually indistinguishable from passive therapeutic lymphocytotoxic antibodies (LyAb), e.g. antilymphocyte globulin (ALG), antithymocyte globulin (ATG) and OKT3, by standard lymphocytotoxicity tests (LCTs). Herein, an extended technique capable of distinguishing between these two types of antibodies is described.

MATERIALS AND METHODS

Serum samples from 11 patients who received therapeutic antibodies were screened for HLA-Ab by LCTs. The administered LyAb were murine OKT3 (n = 2), equine ALG (n = 3), rabbit ATG (n = 2), and combinations of ALG and OKT3 (n = 1), ATG and ALG (n = 1), and ATG and OKT3 (n = 2). To discriminate between therapeutically applied antibodies and active HLA alloimmunization, the sera were preincubated with species-specific anti-Fc IgG, thus blocking the therapeutic antibodies.

RESULTS

The sera of all patients treated showed strong positive lymphocytotoxic reactions [panel reactive antibodies (PRA) 50-100%]. After incubation with the corresponding Fc antibodies, in 9 of the 11 samples the amount of PRA decreased to the level present before transplantation (0-18%). In the remaining cases, new-onset alloimmunization was detected.

CONCLUSION

This extended LCT allows the screening of serum samples for active HLA-Ab even in the presence of therapeutic LyAb.

Ceftriaxone-induced immune haemolysis: two case reports and a concise review of the literature

BACKGROUND AND OBJECTIVES

In this report, we will describe the occurrence of intravascular immune haemolytic anaemia (IHA) associated with ceftriaxone and/or its metabolites in two of our patients. Serological examinations were carried out to demonstrate and characterise the causative antibodies. The findings of all previously reported cases will also be discussed.

MATERIALS AND METHODS

Direct antiglobulin tests (DAT) and indirect antiglobulin tests were performed according to standard procedures. Tests for drug-dependent antibodies were performed in the presence and absence of the target drugs and their ex vivo antigens (in the urine of patients treated with the drugs).

RESULTS

Ceftriaxone-related haemolysis resulted in the death of one of our patients (patient 2), and caused acute renal failure in the other (patient 1). The DATwas strongly positive for anti-C3d and anti-IgG in one case (patient 2), and for anti-C3d alone in the other (patient 1). The serum of patient 1 reacted with red blood cells only in the presence of ex vivo antigens, while that of patient 2 reacted positively to native ceftriaxone and its ex vivo antigen. In the latter patient, the antibodies appeared to cross-react with native cefotaxime whereas, in the first patient, they weakly cross-reacted only with the ex vivo antigens of cefotaxime and cefpodoxime proxetil.

CONCLUSION

Ceftriaxone and/or its trace metabolites may induce life-threatening IHA in children and adults. Serological work-up must include tests to determine the cross-reactivity of ceftriaxone-dependent antibodies to avoid immune haemolysis due to administration of structurally related cephalosporins in affected patients.

Vaccination-associated immune hemolytic anemia in two children

BACKGROUND

Two children in whom acute autoimmune hemolytic anemia (AIHA) developed after vaccination were studied.

CASE REPORTS

The children were a 20-month-old girl and a 21-month-old boy. The diagnosis of AIHA was made in accordance with established criteria (hemolysis, positive DAT, and lack of other reasons for the hemolysis). Serologic tests were performed according to standard technique.

RESULTS

The girl experienced two attacks of hemolysis. The first episode occurred 2 weeks after oral polio vaccination, and the second episode was observed 7 months later, when she received a simultaneous vaccination against mumps, rubella, and measles. The DAT was strongly positive with anti-C3d. No autoantibodies were detectable in either episode. The boy experienced acute hemolysis a few days after a simultaneous revaccination against diphtheria-pertussis-tetanus, Haemophilus influenzae, hepatitis B, and polio. The DAT using anti-IgG was strongly positive, and the DAT performed with anti-C3d was weakly positive.

CONCLUSION

Vaccination-induced AIHA resembles those forms of AIHA related to infectious diseases, and it may occur more frequently than has been reported.

Immunomagnetic selection of CD34+ cells: factors influencing component purity and yield

BACKGROUND

In immunomagnetic selection of CD34+ cells from HPC transplants, not all factors that affect yield and purity of CD34+ cells are known.

METHODS

Forty-three consecutive procedures of immunomagnetic selection of CD34+ cells from peripheral blood HPCs and bone marrow harvests (autologous harvests, n = 27; allogeneic harvests; n=16) were performed by use of a cell selection system (Isolex 300i, Baxter Immunotherapy). The composition of the starting component and the subsets of CD34+ cells were analyzed for correlation with the yield and purity of the final component.

RESULTS

The mean purity of the final components was 84.3 percent (range, 27-99%), and the mean yield was 51.4 percent (range, 9.4-80. 4%). Partial regression analysis showed that, among the factors correlating with purity and/or yield, the RBC volume in the starting fraction had the highest predictive impact on the purity and yield of CD34+ cells, even after the exclusion of procedures using bone marrow harvests as an HPC source (beta coefficient, -0.704; p = 0. 001).

CONCLUSION

The use of the Isolex 300i system allows efficient recovery of CD34+ cells in routine selection procedures. The volume of RBCs in the starting component should be minimized to ensure a high yield and purity of the final component.

Determination and Successful Transfusion of Anti-Gerbich-Positive Red Blood Cells in a Patient with a Strongly Reactive Anti-Gerbich Antibody

Background: The clinical relevance of antibodies directed against members of the Gerbich (GE) family of antigens is not invariably clear. Given the scarcity of serologically compatible red blood cells (RBC), various methods may have to be applied to assess the safety of transfusing serologically incompatible RBC. Patient and Methods: The serum of a 57-year-old male Caucasian admitted to hospital for gastrectomy was found to contain a highly reactive anti-GE2 antibody (IgG(1)). In addition to a monocyte monolayer assay, 50 ml of GE2-positive RBC were transfused, and blood samples were taken before and 1 and 24 h after transfusion for flow-cytometric determination of transfused cells. Results: Both tests showed no increased destruction of GE2-positive RBC. The transfusion of 4 units of GE2-positive RBC was well tolerated, and hemoglobin increased adequately. Conclusion: This case may extend the information available not only on antibodies directed against members of the GE family of antigens but also on methods to estimate the survival of transfused RBC. Copyright 2000 S. Karger GmbH, Freiburg

[Gel agglutination test--a new test system for semiquantitative detection of feto-maternal transfusion in Rhesus incompatibility]

BACKGROUND

The postpartum administration of an adequate amount of anti-D immunoglobulin to the mother in cases of Rhesus incompatibility requires the exact quantification of the amount of Rh-positive fetal cells that may be present in the Rh-negative maternal circulation. The classical methods to detect an intrapartum fetomaternal hemorrhage are either time-intensive (such as the Kleihauer-Betke test), of low specificity (such as the indirect Coombs test), or technically cumbersome (such as flow cytometry). The goals of our study were to develop a simple screening test that may be used routinely to quantify fetomaternal hemorrhage in cases of Rhesus incompatability and to evaluate this test in clinical practice.

STUDY DESIGN AND METHODS

In cases of Rhesus-negative mothers of Rhesus-positive neonates, 2.5 ml of maternal Rhesus negative blood was sampled in an EDTA tubes immediately postpartum and was incubated with anti-D antibodies. Thereafter, a semiquantitative determination was made of the amount of antibody that remained unbound in the serum via a gel agglutination test (GAT) (DiaMed., Switzerland) after mixing with test red blood cells. The amount of anti-D consumed (bound to fetal cells in the first phase) is the semi-quantitatively indicated by the degree of positivity in the second phase the weaker reaction--the more anti-D absorbed in the first phase--the more Rhesus-positive fetal cells present in the maternal sample--the larger the fetomaternal hemorrhage. Following the development of a discrimination zone using this GAT which could ascertain an Rhesus-positive erythrocyte concentration of over 0.2%, the test was applied in a clinical setting. Between September 1995 and April 1998 in unselected postpartum blood samples from 603 Rhesus negative parturients, the GAT was used to test the same blood samples as those requiring evaluation for HbF concentration using the traditional Kleihauer-Betke test.

RESULTS

In 585 of the 603 cases (97%) there was no evidence of a fetomaternal transfusion following testing using both methods. Furthermore, both tests showed significant evidence for a fetomaternal transfusion in five cases. The Kleihauer-Betke test was false-positive in three cases of mothers who had a hereditary elevation of the HbF concentration. The GAT showed three false-positive reaction due to a Dweak maternal varient. In two cases, the disparity between the GAT and the Kleihauer-Betke test could be attributed to an antecedant dose of anti-D antibody. In the two cases, the Kleihauer-Betke test results were 0.3% while the GAT was only 0.2%.

CONCLUSION

The GAT may be used as a screening method in routine clinical practice. This is a quick test that allows for the specific determination and semiquantitative evaluation of the Rh-positive erythrocyte concentration in clinically relevant concentrations. Thus, following a positive GAT screening test, a further specific test such as the Kleihauer-Betke test may be utilized to absolutely quantify the amount of blood transfused from fetus to mother. It is also possible to perform such a quantification test with the GAT by eventually using a diluted maternal blood sample.

Alterations in expression and in serum activity of dipeptidyl peptidase IV (DPP IV, CD26) in patients with hyporectic eating disorders

The notion that patients with eating disorders maintain a functional immunosurveillance in spite of severe malnutrition has attracted researchers for years. Dipeptidyl peptidase IV (DPP IV), a serine protease with broad tissue distribution and known activity in serum, operates in the cascade of immune responses. Membrane-bound DPP IV expressed on lymphocytes, also known as the leucocyte antigen CD26, is considered to participate in T-cell activation. We hypothesized that the activity of DPP IV in serum and expression of CD26 in lymphocytes may be altered in patients with eating disorders. Serum DPP IV activity and the number of CD26 (DPP IV)-positive peripheral blood lymphocytes were measured in 34 patients [anorexia nervosa (AN): n = 11, bulimia (B): n = 23] in four consecutive weekly analyses. In addition, the expression of CD25 (interleukin-2 receptor alpha chain) was evaluated to estimate the degree of T-cell activation. The same analyses were carried out in healthy female volunteers (HC, n = 20). CD2-CD26-positive cells were reduced in patients compared with healthy controls [mean 40.2% (AN) and 41.1% (B) versus 47.4% (HC), P < 0.01], while the DPP IV activity in serum was elevated [mean 108.4 U/l (AN) versus 91.1 U/l (B) and 80.3 U/l (HC), P < 0.01]. The potential implications of our observations on, and beyond, immune function are discussed.

Percutaneous management of renal calculi: experience with percutaneous nephrolithotomy in 60 children

PURPOSE

We report our experience with percutaneous nephrolithotomy in a pediatric population in which primary as well as recurrent stone episodes are frequent and the need for less invasive procedures is imperative.

MATERIALS AND METHODS

Percutaneous nephrolithotomy was performed in 60 children 3 to 13 years old (average age 6), including 44 boys (73.3%) and 16 girls (26.7%). There was a single obstructing renal calculus in 43 patients, while 17 had multiple calculi. The procedure was performed in 1 stage in 49 patients, and it was staged with preliminary nephrostomy in 11 who presented with calculous anuria and elevated serum creatinine. Normal saline was used as an irrigant and perioperatively serum electrolytes were measured to monitor fluid absorption in 18 patients. Stones were extracted intact from 40 patients (66.6%) and ultrasonic lithotripsy was performed in 20 (33.3%).

RESULTS

Of the 60 patients 50 (83.3%) were rendered stone-free at 1 session. Incomplete stone clearance at 1 session was due to intraoperative bleeding requiring blood transfusion, extravasation, multiple stones that were inaccessible via 1 tract, displacement of stone fragments into an inaccessible calix and insignificant residual fragments less than 3 mm. in 2 cases each. During followup of 3 months to 6 years (average 1 year) no late complications were noted.

CONCLUSIONS

Percutaneous nephrolithotomy is a safe and relatively efficacious mode of managing pediatric renal calculi. Although higher success rates are achieved in adults, caution should be exercised in children, in whom diligent attempts at stone clearance in 1 session may be made at the expense of safety.

Simultaneous genotyping of human platelet antigens (HPA) 1 through 6 using new sequence-specific primers for HPA-5

BACKGROUND

Polymerase chain reaction using sequence-specific primers is widely used for genotyping human platelet antigens (HPA). However, the results of HPA-5 genotyping are still problematic.

STUDY DESIGN AND METHODS

New sequence-specific primers were designed for HPA-5 that, together with already published primers, allow simultaneous genotyping of HPA-1, -2, -3, -4, -5, and -6. The reliability of the described protocol was determined by using reference DNA samples as well as samples from healthy blood donors.

RESULTS

All primers produced specific amplification products. The genotype and the previously ascertained phenotype of the tested specimens were in concordance in all cases.

CONCLUSION

The described polymerase chain reaction protocol allows rapid, reliable, simultaneous genotyping of HPA-1, -2, -3, -4, -5, and -6.

Rapid detection of heparin-induced platelet antibodies with particle gel immunoassay (ID-HPF4)

Early and acute diagnosis is needed to prevent thromboembolic complications in heparin-induced thrombocytopenia. We developed a particle agglutination assay that allows the detection of such antibodies within 20 min.

Fatal immune haemolysis due to a degradation product of ceftriaxone

A 16-year-old girl who was treated with ceftriaxone developed two intravascular haemolytic attacks that led to acute renal failure and death. The direct antiglobulin test was positive only for C3d, and no ceftriaxone-dependent antibodies were detectable. Her serum reacted strongly positive with red blood cells in the presence of ex vivo antigen related to ceftriaxone (urine samples from patients receiving the drug). This is the first reported case in which the causative antibodies appeared to be stimulated solely by a degradation product of ceftriaxone.

Demonstration of drug-dependent antibodies in two patients with neutrophenia and successful treatment with granulocyte-colony-stimulating factor

BACKGROUND

Many drugs have been reported as being capable of inducing immune neutropenia, but the causative drug-dependent antibodies were rarely demonstrated.

STUDY DESIGN AND METHODS

This report describes the results of serologic testing and treatment in two children with immune neutropenia related to cefotaxime and metamizole, respectively. Serum samples were tested in the presence and the absence of the drugs using the granulocyte agglutination test (GAT), the granulocyte immunofluorescence test (GIFT), and the monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA) assay.

RESULTS

The serum of one child contained cefotaxime-dependent antibodies that were detectable by the GAT and the MAIGA assay, but not by the GIFT. The serum of the other child gave positive reactions in the GAT and GIFT due to HLA antibodies and in the MAIGA assay only in the presence of metamizole. While cefotaxime-dependent antibody was directed against CD16, the metamizole antibody was directed against CD11b and CD35. The administration of granulocyte-colony-stimulating factor led to an abrupt increase in circulating neutrophils in both cases.

CONCLUSION

The use of more than one technique is necessary for detection of drug-dependent antibodies against neutrophils, and early administration of granulocyte-colony-stimulating factor may result in fewer complications in these patients.

Do we have a less severe form of Kawasaki disease or is it the gammaglobulin effect?

This study was undertaken to evaluate the incidence of coronary artery aneurysms (CAA) in Kawasaki disease (KD). We reviewed the clinical and echocardiographic findings of 135 children who presented to our center with KD between December 1986 and December 1997. The age of onset ranged between 3months to 13 years (median 2 years). The male to female ratio was 1.54:1. All patients received intravenous Gammaglobulin (IVGG) during the acute stage. The echocardiogram, which was done between 2-3 weeks of the onset of fever, was normal in 106 patients (78.5%). Follow-up studies over a period of 6 months to 1 year remained normal. Minimal right or left coronary artery wall ectasia without dilatation or aneurysm formation was seen in 16 (11.85%). Follow-up of these patients showed disappearance of these changes over 6 weeks to 6 months. One patient (0.74%) had generalised dilatation of all the coronary arteries during the acute stage. This has normalized over a period of 9 months. A total of 10 (7.4%) had CAA during the acute stage. On follow-up of 8 of these patients for an average 3 months to 1.5 years all CAA regressed completely. One patient had residual Giant CAA after 1 year follow-up. One patient with CAA was lost to follow-up. One patient (0.74%) had pericardial effusion and another one (0.74%) had mitral incompetence during the acute stage only, both had no coronary involvement. None of our patients had cardiac failure, arrhythmia, myocardial infarction or death. We conclude that coronary artery changes due to KD are less common and less severe in our patients than those seen in other studies. We speculate that this can be related partly to the early administration of IVGG. The difference in incidence of CAA secondary to KD among different racial groups warrants more detailed genetic studies.

The linkage between Na+ uptake and ammonia excretion in rainbow trout: kinetic analysis, the effects of (NH4)2SO4 and NH4HCO3 infusion and the influence of gill boundary layer pH

The nature of the linkage between between branchial ammonia excretion (JAmm) and unidirectional Na+ influx (JNain) was studied in the freshwater rainbow trout (Oncorhynchus mykiss). Arterial plasma total [ammonia], PNH3 and JAmm were all elevated approximately threefold by intravascular infusion for 24 h with either 70 mmol l-1 (NH4)2SO4 or 140 mmol l-1 NH4HCO3 at a rate of approximately 400 micromol kg-1 h-1. Both treatments markedly stimulated JNain. NH4HCO3 induced metabolic alkalosis in the blood plasma, whereas (NH4)2SO4 caused a slight metabolic acidosis. Experiments with Hepes-buffered water (5 mmol l-1) under control conditions demonstrated that increases in gill boundary layer pH were associated with decreases in both JNain and JAmm. Thus, the stimulation of JNain caused by ammonium loading was not simply a consequence of a Na+-coupled H+ extrusion mechanism activated by internal acidosis or by alkalosis in the gill boundary layer. Indeed, there was no stimulation of net acidic equivalent excretion accompanying NH4HCO3 infusion. Michaelis-Menten kinetic analysis by acute variation of water [Na+] demonstrated that both infusions caused an almost twofold increase in JNamax but no significant change in Km, indicative of an increase in transporter number or internal counterion availability without an alteration in transporter affinity for external Na+. The increase in JNain was larger with (NH4)2SO4 than with NH4HCO3 infusion and in both cases lower than the increase in JAmm. Additional evidence of quantitative uncoupling was seen in the kinetics experiments, in which acute changes in JNain of up to threefold had negligible effects on JAmm under either control or ammonium-loaded conditions. In vitro measurements of branchial Na+/K+-ATPase activity demonstrated no effect of NH4+ concentration over the concentration range observed in vivo in infused fish. Overall, these results are consistent with a dominant role for NH3 diffusion as the normal mechanism of ammonia excretion, but indicate that ammonium loading directly stimulates JNain, perhaps by activation of a non-obligatory Na+/NH4+ exchange rather than by an indirect effect (e.g. Na+-coupled H+ excretion) mediated by altered internal or external acid-base status.

Quinine-induced immune thrombocytopenic purpura followed by hemolytic uremic syndrome

Immune thrombocytopenic purpura (ITP) mediated by quinine-dependent platelet reactive antibodies is well recognized. More recently there have been a number of reports of quinine-induced hemolytic-uremic syndrome (HUS). We describe a patient with quinine-induced immune thrombocytopenia who subsequently developed HUS after re-exposure to a single dose of this drug. To our knowledge, this is the first such case reported. Multiple quinine-dependent antibodies have been characterized in the patient's serum. Initially, quinine-dependent antibodies were directed solely against the platelet glycoprotein complex GPIb/IX. After rechallenge with quinine, there was broadening of quinine-dependent antibody specificities, which were now also directed against the platelet glycoprotein complexes GPIb/IX and GPIIb/IIIa, endothelial cells, and leukocytes. We have shown quinine-dependent antibody-mediated endothelial cell activation, which supports an immunopathogenic role for quinine-dependent antibodies in the causation of this disease.

Detection of tumor cells in peripheral blood samples from patients with germ cell tumors using immunocytochemical and reverse transcriptase-polymerase chain reaction techniques

The aim of this study was to establish sensitive techniques for the detection of residual germ cell tumor cells in peripheral blood and progenitor cell harvests. For this purpose, we used immunocytochemical staining for cytokeratin filaments and reverse transcriptase-polymerase chain reaction (RT-PCR) for epidermal growth factor receptor (EGF-R) and germ cell alkaline phosphatase (GCAP). Germ cell tumor lines Tera-1 and Tera-2 were titrated into normal peripheral blood. Immunocytochemical staining allowed detection of one cytokeratin-positive tumor cell in 10(5) cells. RT-PCR for EGF-R revealed one tumor cell in 10 cells for Tera-1 and one tumor cell in 10(3) cells for Tera-2, while RT-PCR for GCAP displayed a sensitivity of one tumor cell in 10(6) cells for Tera-1, one tumor cell in 10(4) cells for Tera-2, and no positivity in normal mononuclear cells (n = 20) and progenitor cell harvests (n = 5). The analysis of peripheral blood and progenitor cell harvests from 20 patients with germ cell tumors revealed tumor cell contamination in three patients using immunocytochemical staining and in seven patients by RT-PCR for GCAP. We conclude that RT-PCR for GCAP appears to be suitable for the sensitive detection of residual germ cell tumor cells in peripheral blood and progenitor cell harvests.

Regulation of ion transport across lamprey (Lampetra fluviatilis) erythrocyte membrane by oxygen tension

We have measured the effects of oxygen tension on the transport of Na+, K+ and Cl- across the erythrocyte membrane of the lamprey Lampetra fluviatilis. The transport of each ion was affected by the oxygen tension of the medium. Hypoxic conditions (PO2 2 kPa) caused an increase in the acidification-induced influx of Na+ via Na+/H+ exchange. The influx of K+ was only slightly affected by the oxygenation of the medium. In contrast, the basal K+ efflux, measured using the radioactive isotope 43K, was markedly reduced by decreasing the oxygen tension of the medium, whereas the K+ flux in hypotonic medium was not affected. Only minor effects of hypoxic conditions on the influx of Cl- were observed in either isotonic or hypotonic conditions (there was a tendency for the isotonic influx to increase) or on the efflux in isotonic conditions. However, deoxygenation caused a marked reduction in the Cl- efflux in hypotonic conditions. The results show that oxygen tension has a marked effect on the pH and volume regulatory transport pathways of lamprey erythrocytes. For K+ and Cl-, the regulation appears to be asymmetric, i.e. influx and efflux are affected differently.

Regulation of ion transport across lamprey (Lampetra fluviatilis) erythrocyte membrane by oxygen tension

We have measured the effects of oxygen tension on the transport of Na+, K+ and Cl- across the erythrocyte membrane of the lamprey Lampetra fluviatilis. The transport of each ion was affected by the oxygen tension of the medium. Hypoxic conditions (PO2 2 kPa) caused an increase in the acidification-induced influx of Na+ via Na+/H+ exchange. The influx of K+ was only slightly affected by the oxygenation of the medium. In contrast, the basal K+ efflux, measured using the radioactive isotope 43K, was markedly reduced by decreasing the oxygen tension of the medium, whereas the K+ flux in hypotonic medium was not affected. Only minor effects of hypoxic conditions on the influx of Cl- were observed in either isotonic or hypotonic conditions (there was a tendency for the isotonic influx to increase) or on the efflux in isotonic conditions. However, deoxygenation caused a marked reduction in the Cl- efflux in hypotonic conditions. The results show that oxygen tension has a marked effect on the pH and volume regulatory transport pathways of lamprey erythrocytes. For K+ and Cl-, the regulation appears to be asymmetric, i.e. influx and efflux are affected differently.

Use of the gel agglutination technique for determination of fetomaternal hemorrhage

BACKGROUND

Adequate administration of Rh immune globulin requires an accurate determination of the number of D-positive cells in the circulation of D-negative women. Although several tests have been described for the detection of fetomaternal hemorrhage, there is still a need for a rapid, simple, and clinically relevant screening test.

STUDY DESIGN AND METHODS

Serial dilutions of a monoclonal anti-D were incubated with stock solutions (0.2 mL) of adult D-negative red cells in the absence or presence of various amounts of fetal D-positive cells (0.1, 0.2, 0.3, 0.4, and 0.5%). After incubation, the supernatants were tested against D-positive red cells by using the new, gel agglutination technique (GAT). After the GAT was adapted to detect D-positive cells at concentrations of > or = 0.2 percent, unselected postpartum samples from D-negative women (n = 420) who delivered D-positive infants were analyzed by both the new test and the Kleihauer-Betke test (KBT).

RESULTS

Three of a total of 420 postpartum samples were positive (> or = 0.4% fetal cells), and 406 were negative in both tests. One had 0.5-percent fetal cells in the KBT and gave negative results in the GAT. The latter test was, however, performed after administration of Rh immune globulin. The KBT gave false-positive results in two cases, because of hereditary persistence of hemoglobin F, and the GAT gave a false-positive reaction in one case because of a maternal weak D variant. In the remaining seven cases, the KBT results were only weakly positive (0.2%) and could not be attributed solely to D positive red cells.

CONCLUSION

The GAT is suited for routine screening. It provides rapid and specific detection of D-positive red cells at clinically relevant concentrations. The test may (rarely) yield false-negative results due to insufficient administration of Rh immune globulin before testing.

The diversity of the HLA class I introns reflects the serological relationship of the coding regions

The introduction of PCR-based HLA typing techniques has uncovered that the HLA system is much more variable than it has been expected from the conventional typing methods. More and more new alleles are detected which are not characterized by new sequence motifs, but by new combinations of already existing sequence motifs. This variability, reflecting the immunological necessity to have the greatest capacity for presenting antigenic peptides, is increasingly complicating DNA typing techniques based on the diversity of the coding region. We have determined the sequence of the 1st through 3rd intron of the majority of HLA-A and HLA-B alleles in 48 well-defined cell lines and 195 PCR-typed clinical samples. The few published sequences emerged to contain substantial errors. The introns turned out to be highly polymorphic. Besides extensive homologies, numerous locus- and group-specific sites could be identified. The most intriguing finding was that most of the polymorphic motifs were related to serological families. These sequence motifs were extremely beneficial for setting up PCR-based typing systems. In particular, sequencing-based typing strategies benefited from intron-restricted priming for amplification and sequencing by enabling complete analysis of the polymorphic exons. The determination of cis/trans linkages of sequence motifs was substantially facilitated. Apart from these advantages, the intron sequences were useful for evolutionary studies, delivering more insights into the genetic relationship between different alleles and the mechanisms involved in the development of the diversity of HLA. Moreover, the variability of the introns may provide a structural basis for the identification of regulatory elements acting on the level of transcription.

Pulsed high-dose dexamethasone in chronic autoimmune haemolytic anaemia of warm type

The management of patients with autoimmune haemolytic anaemia of warm type (AIHA) is often problematic. Recently, pulsed high-dose dexamethasone (HDD) has been shown to be effective in the treatment of autoimmune thrombocytopenic purpura (AITP). In this study we treated seven patients with AIHA with HDD. The regimen recommended for treatment of refractory AITP (40 mg dexamethasone for 4 d at the beginning of each 28 d cycle) was employed in almost all cases. Prior to dexamethasone administration, haemolysis was decompensated in all seven patients. HDD was well tolerated and led to an improvement of haemolysis in all cases.

Diclofenac-induced immune haemolytic anaemia: simultaneous occurrence of red blood cell autoantibodies and drug-dependent antibodies

During the last 5 years we have identified a total of 17 patients (nine females and eight males aged between 53 and 85 years) with immune haemolytic anaemia related to diclofenac (a nonsteroidal anti-inflammatory drug). All patients developed acute intravascular haemolysis. Two patients died, and eight patients developed temporary renal failure that required haemodialysis. The direct antiglobulin test was positive with anti-IgG and anti-C3d in all cases, with anti-IgA in 4/10 cases tested, and negative with anti-IgM. The indirect antiglobulin test was moderately or weakly positive in 11 cases, and IgG autoantibodies could be eluted from the red blood cells (RBCs) of all patients. Initially, the diagnosis of autoimmune haemolytic anaemia of warm type was suggested in all cases. All patients had simultaneously developed autoantibodies and drug-dependent antibodies. The majority of drug-dependent antibodies (n = 13) reacted with urine containing the drug and its metabolites (ex vivo antigen), the native drug, and diclofenac-treated RBCs. The antibodies in the remaining four cases were detectable only in the presence of ex vivo antigen. Diclofenac appears to bind only weakly to RBCs in the absence of the drug-dependent antibodies. We conclude that diclofenac forms neoantigens with RBCs that may stimulate the production of autoantibodies and drug-dependent antibodies. The resulting haemolytic syndrome is very similar to autoimmune haemolytic anaemia of warm type.

Vesicouterine fistula--variable clinical presentation

Vesicouterine and vesicocervical fistula are mostly caused by trauma during lower segment caesarian section. The clinical presentation and management of nine cases are described. Presentation was typical, i.e. cyclic haematuria (menouria) without urinary leakage, in three of the nine patients, and atypical--vaginal leakage of urine, urethral passage of lochia and/or regular vaginal menes--in six patients. The diagnosis was made clinically, radiologically and endoscopically. Surgical repair was successfully performed in eight cases and one was managed conservatively with satisfactory outcome. Atypical presentation of such fistulas may considerably delay the diagnosis. In contrast to vesicovaginal fistula, conservative management may be tried in selected cases.

The effects of repeated physical stress on the b-adrenergic response of the rainbow trout red blood cell

The effects of a 7-day period of daily physical stress (chasing until exhaustion) on the beta-adrenergic response of the rainbow trout (Oncorhynchus mykiss) red blood cell (rbc) were examined in vitro. Physical stress was associated with pronounced increases in the circulating levels of the catecholamine hormones (adrenaline and noradrenaline) measured on days 1, 3 and 7 of the stress regime. After 7 days, the numbers of high-affinity cell surface beta-adrenoceptors were reduced in the physically stressed fish when measured in vitro under conditions of normoxia (20 % reduction) or hypoxia (30 % reduction). Under hypoxic conditions, the binding affinity of the rbc beta-adrenoceptor was significantly higher in the stressed fish. Although the stressed fish had fewer beta-adrenoceptors, rbc adrenergic responsiveness was enhanced after 7 days of physical stress as determined from dose-response curves relating noradrenaline concentration to water and Na+ accumulation (indices of rbc adrenergic Na+/H+ exchange activity). The EC50 values (concentrations yielding half-maximal responses) for noradrenaline were lowered significantly by 1.7- to 3.9-fold in the blood from physically stressed fish. The enhanced adrenergic responsiveness of the rbcs appeared to be unrelated to changes in the initial steps of the beta-adrenergic signal transduction pathway leading to cyclic AMP production because physical stress was without effect on the magnitude or the dose-dependency of rbc cyclic AMP accumulation. To determine whether post-cyclic-AMP events were affected by physical stress, water and Na+ accumulation were measured in rbcs that had been incubated with the permeable cyclic AMP analogue 8-bromo cyclic AMP. The EC50 values for 8-bromo cyclic AMP were lowered by 1.6- to 1.7-fold in the blood from stressed fish. These experiments demonstrate that repeated physical stress significantly enhances the adrenergic responsiveness of the rainbow trout rbc, presumably by modifying the sensitivity of the Na+/H+ exchanger (or the steps immediately preceding exchanger activation) to cyclic AMP. The results are discussed with respect to the interrelationships between chronic and acute stress responses in fish.

Sequence analysis of the 2nd intron revealed common sequence motifs providing the means for a unique sequencing based typing protocol of the HLA-A locus

We here present a sequencing strategy for the HLA-A locus which is generally applicable for all HLA class I genes. The typing strategy is based on a group-specific amplification according to the serologically defined antigens. The PCR products carry the typing-relevant polymorphic regions of the 2nd and 3rd exon including the 2nd intron. The sequencing primers were designed to match conserved sequence motifs in the 2nd intron allowing a nested sequencing approach in 3' and 5' direction. These conserved regions were identified after sequence compilation of the 2nd intron of 143 clinical samples and 48 cell lines mostly from the 9th and 10th IHWC representing all serologically defined groups of alleles. This strategy allowed the use of only one 5' and one 3' sequencing primer regardless of the amplified allele. Therefore, it was possible to use dye terminator as well as dye primer sequencing chemistry. The amplification strategy allowed the separation of the haplotypes in almost all cases. Thus, an assignment of heterozygous positions requiring high sequencing quality was not necessary, allowing the application of Sequenase as well as TaqPolymerase as sequencing enzyme. Concerning the resolution of heterozygosity it is obvious that this approach is superior to a typing system using a single pair of generic primers followed by direct sequencing, since the latter technique is not capable of defining the cis/trans linkage of polymorphic sequences and, hence, cannot exclude the presence of unknown alleles.

Discrimination of HLA-B27 alleles by group-specific amplification followed by solid-phase sequencing

HLA-B27 is known to be highly associated with ankylosing spondylitis. Until now, nine B27 subtypes have been sequenced and may contribute in different fashions to ankylosing spondylitis. Additionally, the divergent subtypes may be of clinical importance in bone marrow transplantation with alternative donors. The purpose of this study was to determine the different subtypes of HLA-B27 by a direct sequencing approach. The typing strategy is based on a group-specific amplification of the second and third exon followed by automated fluorescence sequencing of the polymorphic regions. The extensive sharing of sequence motifs between the different B alleles made it impossible to specifically amplify the B27 group under the precondition of including all sequence variations necessary for a postamplification specificity step. Therefore, for setting up a direct sequencing approach of B27, co-amplified B alleles had to be taken into account. In order to get unambiguous sequencing chromatograms without any heterozygous positions, nested sequencing primers were used which selectively matched sequence motifs only present in the second and third exon of the amplified B27 alleles. This strategy allowed in all cases investigated a clear separation of the haplotypes, revealing unequivocal sequencing results. Using this method, we have investigated 93 B27-positive individuals. Sequencing identified the alleles B*2702, 2703, 2704, 2705, and 2707. B*2701, 2706, 2708, and 2709 were not represented in the population studied.

Complete subtyping of the HLA-A locus by sequence-specific amplification followed by direct sequencing or single-strand conformation polymorphism analysis

A variety of reasons related to the HLA class I system has complicated the application of molecular approaches to HLA class I typing. Here we present a PCR-based HLA-A typing strategy considering the sequence variations of the two most polymorphic exons which allows complete subtyping of the HLA-A locus. The method is based on a sequence-specific amplification identifying the serologically defined HLA-A specificities. The PCR products generated by these group-specific primers bear the sequence information necessary for a postamplification specificity step. The primer pairs are located within one exon, either exon 2 or exon 3, which avoids amplification of polymorphic intron sequences allowing subsequent single-strand conformation polymorphism analysis and facilitating direct sequencing. Using this method we investigated 48 cell lines and 153 clinical samples. 23 PCR reactions are performed per individual for the assignment of the serological specificities A1-A80. The reproducibility was 100% in all cell lines and 85 clinical samples typed on two separate occasions. With the exception of 13 out of 231 possible serological combinations all homozygous and heterozygous combinations of A1-A80 can be distinguished by specific amplification patterns. Comparing the PCR based typing results with those of serology in 12% a discrepancy was found. Solid-phase sequencing or SSCP analysis of the group-specific PCR fragments allowed complete subtyping of the HLA-A locus. This strategy can identify all 48 HLA-A alleles based on the sequence variations of the 2nd and 3rd exon. 1128 homozygous and heterozygous allele combinations are possible for the HLA-A locus. Only 4 out of these 1128 allele combinations remained unresolved.

A novel HLA-DR13 allele (DRB1*1314) identified by single-strand conformation polymorphism analysis and confirmed by direct sequencing

A novel variant of the HLA-DR13 group is described. The new allele was found in a DR10, 13 heterozygous patient of Turkish origin, two HLA genotypically identical children of the patient typed as DR11,13, and one child typed as DR13,13. DR13 subtyping of the patient was initially performed by SSCP analysis of PCR-amplified DNA, using the 11th OHWS primers DRBAMP-3 and DRBAMP-B. Due to an unusual SSCP banding pattern, the PCR product was subjected to solid-phase sequencing. The sequence of the new allele, DRB1*1314, is different from that of DRB1*1307 by a single nucleotide substitution in codon 47, with T replacing consensus A. This results in a single amino acid change of tryptophan to phenylalanine in the first domain of the DR beta chain.