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Biomedical subjects

A Salama

Publications and source records attributed to A Salama.

At least 19 recordsLinked to original sources
PubMed2006

Diagnosis of gonococcal infection in high risk women using a rapid test.

OBJECTIVE: To assess the performance and acceptability for patients and health care workers of the NGThermo Biostar (GC OIA) to diagnose gonococcal infection compared with culture using modified Thayer Martin medium. METHODS: This study involved 326 high-risk women presenting with vaginal discharge or referral by sexual partner with urethral discharge at a sexually transmitted infections (STI) clinic in Manaus, Brazil. Endocervical swabs collected from the women were tested with both the NG Biostar and modified Thayer Martin culture as the reference standard test. Clinic staff were trained to perform the NG Biostar on site and the culture was performed in the laboratory of the clinic. RESULTS: The prevalence of gonococcal infection as measured by the reference standard was 15% (50/326) overall. Among asymptomatic participants, the prevalence of infection was 17.7% (25/141) and among symptomatic women it was 13.5% (25/185) (p = 0.3). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the NG Biostar test, with 95% confidence intervals (CI), were 60% (46.4% to 73.6%), 89.9% (86.2% to 93.6%), 55.6% (42.4% to 68.8%), and 92.6% (89.5% to 95.7%), respectively; 98.8% of study participants were willing to wait approximately 1 hour in the clinic for test results. CONCLUSION: Syndromic management protocols for treatment of STI in developing countries require refinement because, as currently described, they lead to over-treatment of cervical infection. A rapid test done during patients' initial presentation and leading to immediate treatment if positive would help improve the accuracy of diagnosis and could also be used to screen asymptomatic women. Even though the NG Biostar had a low sensitivity and PPV, which is less than ideal, it could still improve the rates of treatment over the gold standard test that requires return visits for patients to receive results and to benefit from treatment. Cost-effectiveness studies using rapid point-of-care tests for Neisseria gonorrhoeae infection compared to the syndromic approach should be carried out to assess their value in STI diagnosis and treatment in developing nations.

Adolescent↗
PubMed2006

Replacement of intravenous administration of anti-D by subcutaneous administration in patients with autoimmune thrombocytopenia.

Intravenous (IV) administration of anti-D in patients with autoimmune thrombocytopenia (AITP) may result in severe hemolysis and even death. Over a 3-year period, we gave anti-D only subcutaneously (SC), and none of our patients have developed any acute adverse reaction. Most importantly, SC delivery of anti-D produces largely the same beneficial effect as obtained by IV anti-D. We recommend replacement of IV administration of anti-D by SC administration in AITP.

Adult↗
PubMed2006

CD47 is expressed at normal levels in patients with autoimmune haemolytic anaemia and/or immune thrombocytopenia.

CD47 deficiency results in lethal autoimmune haemolytic anaemia (AIHA) and mild spontaneous thrombocytopenia in non-obese diabetic mice. It is unknown whether CD47 has an impact on AIHA of the warm type or autoimmune thrombocytopenia (ITP) in humans. Healthy blood donors (n= 11), patients with AIHA (n= 13), patients with ITP (n= 18) and one patient with Rh(null) phenotype were investigated. CD47 expression on red blood cells (RBC), platelets, granulocytes and lymphocytes and in plasma was determined by quantitative flow cytometry. All types of blood cells studied were found to carry CD47. Although CD47 expression on Rh(null) RBCs was decreased, there was no significant difference between CD47 expression on RBCs of healthy blood donors and on those of patients with AIHA or ITP. Similarly, CD47 was detectable in the plasma of the studied subjects. No evidence for a pathogenetic role of CD47 in autoimmune haemolysis or thrombocytopenia in humans could be demonstrated.

Anemia, Hemolytic, Autoimmune↗
PubMed2006

Detection of a new weak A blood-group allele (Aw11).

BACKGROUND AND OBJECTIVES: Weak ABO variants may escape tests using unlicensed sera. MATERIALS AND METHODS: Prior to transfusion, ABO grouping was performed using an automated system and in-house diluted sera, and manual and bedside test techniques. Genotyping and sequencing were performed using standard methods. RESULTS: Initially, the red blood cells (RBC) of the first-time blood donor were typed as B, but pretransfusion testing carried out using the bedside test indicated the presence of an additional A phenotype. Serological re-examination confirmed the bedside test results, and the allele in question was identified, by genotyping, as a new weak A variant (Aw11). CONCLUSIONS: The use of CE-marked and licensed antisera is recommended to avoid ABO mistyping.

ABO Blood-Group System↗
PubMed2006

A simple and practical agglutination assay for human leucocyte antigen-B27 typing.

BACKGROUND AND OBJECTIVES: The human leucocyte antigen (HLA) B27 is the most frequently typed single antigen that is associated with diseases. Here, we describe a simple and rapid particle agglutination assay (PaGIA) for HLA-B27 typing. MATERIALS AND METHODS: Superparamagnetic particles were coated with a monoclonal antibody to HLA-B27 and subsequently used for testing. Anticoagulated whole-blood samples were obtained from healthy blood donors (n = 194) with known HLA patterns and from patients (n = 51) who had been typed positive for HLA-B27 by flow cytometry. RESULTS: The particles agglutinated only after incubation with HLA-27-positive blood samples, using the ID-microtyping system. Positive reactions were clearly distinguishable from negative reactions in all samples tested. Flow cytometric HLA-B27 typing revealed an indeterminate result in one patient. CONCLUSIONS: The new HLA-B27 PaGIA is suitable for rapid typing of HLA-B27. The assay is simple and easy to perform, and can be implemented in any routine laboratory.

Agglutination Tests↗
PubMed2006

A novel antigen-specific capture assay for the detection of platelet antibodies and HPA-1a phenotyping.

BACKGROUND AND OBJECTIVES: The antigen-specific assays currently used for the laboratory investigation of platelet antibodies and antigens are technically complex and cannot be used in most routine laboratories. Here, we describe a simple antigen-specific capture assay (ASCA) for the detection of serum platelet antibodies and for human platelet antigen-1a (HPA-1a) phenotyping. MATERIALS AND METHODS: For the detection of platelet antibodies, platelets from healthy blood donors were incubated with biotinylated monoclonal antibodies to platelet glycoprotein complexes (GP), then solubilized and mixed with superparamagnetic streptavidin particles. Serum samples from patients with autoimmune thrombocytopenia (n = 39), from patients with platelet alloantibodies (6 HPA-1a, 1 HPA-2b, 1 HPA-3a, 6 HPA-5b), and from healthy blood donors (n = 70), were tested. All serum samples from the patients were investigated in parallel by the indirect monoclonal antibody-specific immobilization of platelet antigen assay (MAIPA). For HPA-1a phenotyping, superparamagnetic particles were coated with a monoclonal antibody to HPA-1a and mixed with diluted whole blood samples from healthy blood donors (n = 139), who had previously been genotyped for platelet alloantigens. Results The indirect MAIPA detected autoantibodies in 18%, and the direct MAIPA in 50% of patients tested. In contrast, the new ASCA demonstrated positive results in 77% of patients. All tested alloantibodies reacted positive by the ASCA, and all serum samples from healthy blood donors were negative. The results of HPA-1a phenotyping were in concordance with those of genotyping in all cases. CONCLUSION: In our opinion, the ASCA is easy to perform and much more sensitive than the currently available antigen-specific assays for the detection of platelet antibodies.

Antigens, Human Platelet↗
PubMed2006

ELISA methods detect HLA antibodies with variable sensitivity.

The accuracy of human leukocyte antigen (HLA) antibody screening results is dependent on the technique employed. In this study, a total of 612 serum samples from patients awaiting kidney transplantation were tested by two different enzyme-linked immunosorbent assay (ELISA) methods: LAT-M(R) (One Lambda/BMT) and AbScreen(R) (Biotest). The results of these assays were identical for HLA class I and II antibodies in 524 cases (85.6%), and discrepant in the remaining 88 cases (42 class I, 24 class II, 22 class I and II). More specifically, class I results were in agreement in 26 positive and 522 negative cases and in disagreement in 64 cases. Class II results were the same in 50 positive and 516 negative cases and different in 46 cases. Retesting the samples using LAT 1288 (One Lambda/BMT) and considering previous HLA antibody test results and the history of immunising events, the sensitivity and specificity, respectively, of the two methods were determined as follows: class I: 89.6% and 97.5% (LAT-M) vs. 70.6% and 96.8% (AbScreen), class II: 96.5% and 98.4% (LAT-M) vs. 88.3% and 95.5% (AbScreen). These results indicate that a single ELISA does not invariably prove or exclude the presence of HLA antibodies, and that additional testing is required in some cases.

Antibody Specificity↗
PubMed2006

Report of a patient with heparin-induced thrombocytopenia type II associated with IgA antibodies only.

Heparin-induced thrombocytopenia type II (HIT II) is usually mediated by immunoglobulin G (IgG) antibodies that lead to platelet activation via the FcgammaIIA-receptor. Here we describe a patient who developed HIT II after aortocoronary bypass surgery. His serum contained an antibody that was detectable by the heparin-induced platelet activation assay (HIPA) and by the ID-HPF4 particle agglutination assay. The flow cytometric analysis showed that the antibody was of the IgA class.

Autoantibodies↗
PubMed2006

The effect of the diameter of metal-on-metal bearings on systemic exposure to cobalt and chromium.

The recent resurgence in the use of metal-on-metal bearings has led to fresh concerns over metal wear and elevated systemic levels of metal ions. In order to establish if bearing diameter influences the release of metal ions, we compared the whole blood levels of cobalt and chromium (at one year) and the urinary cobalt and chromium output (at one to three and four to six years) following either a 50 mm or 54 mm Birmingham hip resurfacing or a 28 mm Metasul total hip replacement. The whole blood concentrations and daily output of cobalt and chromium in these time periods for both bearings were in the same range and without significant difference.

Adult↗
PubMed2005

Antibodies against protein Z and fetal loss: current perspectives.

Protein Z (PZ) is a vitamin K-dependent plasma protein that serves as a cofactor for the inactivation of factor Xa. A number of investigators found low PZ levels in patients with haemorrhagic as well as thromboembolic diseases, although there is no clear evidence of a pathogenic link between PZ deficiency and these clinical disorders. Nevertheless, low PZ levels have been found in association with early fetal losses, especially those occurring before the 15th week of gestation and in patients with detectable antiphospholipid and anti-PZ antibodies. The current diagnostic relevance and therapeutic consequences of these parameters will be discussed.

Antibodies↗
PubMed2005

Immunoadsorption patients with multiple sclerosis: an open-label pilot study.

BACKGROUND: Immunoadsorption (IA) is occasionally applied in patients with acute relapses of multiple sclerosis (MS). This pilot study was undertaken to determine whether IA might help in secondary progressive and relapsing-remitting multiple sclerosis. DESIGN: IA was performed at 1-week intervals in 12 patients with secondary progressive or relapsing-remitting MS. These patients had an extended disability status scale (EDSS) score of 4.5-7 and an EDSS increase of 0.5 within 6 months before inclusion in the study despite conventional drug therapy. The change in the EDSS and that in the MS functional composite (MSFC) score, which consisted of quantitative tests of arm function, ambulation, visual acuity and cognition, served as the primary outcome variables, which were measured at baseline and at 3, 6 and 12 months. Changes in quality of life and cerebral lesions by magnetic resonance imaging (MRI) were also assessed at baseline and after the last immunoadsorption (month 3). RESULTS: A significant reduction of the median EDSS change was observed after the treatment period, which reversed 3 months after the immunoadsorptions had been stopped. Ten of 12 patients remained stable during the first year of follow-up with no significant changes of the MSFC scores. No significant changes in magnetic resonance imaging T2-hyperintense brain lesions or in the number of gadolinium-positive lesions and in the patients' quality of life were observed. Western blot analyses demonstrated a reduction of serum myelin-specific antibodies, which were collected in the adsorber eluates. CONCLUSIONS: Removal of immunoglobulins, including myelin-specific antibodies by immunoadsorption, seems to delay disease progression as defined by EDSS, MSFC and MRI, while the patients' quality of life did not deteriorate.

Adult↗
PubMed2005

B*4440: a novel HLA-B allele identified by sequence-specific oligonucleotide hybridization and sequence-specific amplification.

A novel human leukocyte antigen B (HLA-B) allele, B*4440, is described. The allele was identified in an adult stem cell donor of Caucasian origin. HLA-B*4440 most closely matches to B*4403 differing by a substitution of three nucleotides at codon 44, 45, and 50. Thus, low-resolution HLA typing using sequence-specific oligonucleotide hybridization or amplification using sequence-specific primers gave inconclusive results. DNA sequencing confirmed a variation of codons 44 and 45 (AGG AAG-->AGA GAG) and codon 50 (CCA-->CCG), resulting in an amino acid substitution Lys-->Glu at codon 45.

Adult↗
PubMed2005

Identification and characterization of a novel HLA-DRB1 allele, DRB1*0830*.

Here, we report on the identification and characterization of a novel human leukocyte antigen (HLA) DRB1 allele, DRB1*0830. This allele was identified in a candidate for hematopoietic stem cell donation. While the DNA sequence of HLA-DRB1*0830 most closely matches to DRB1*080202, its amino acid sequence resembles DRB1*080202 and DRB1*0813. Due to a substitution at nucleotide position 286 HLA-typing using sequence-specific oligonucleotide hybridization or amplification using sequence-specific primers gave inconclusive results. Allele-specific DNA sequencing confirmed a 286 T-->A substitution resulting in Phe67Ile.

Alleles↗
PubMed2005

Human platelet antigen genotyping by using sequence-specific primers and the particle gel agglutination assay.

BACKGROUND AND OBJECTIVES: Polymerase chain reaction using sequence-specific primers (PCR-SSP) is currently the most widely used technique for human platelet antigen (HPA) genotyping. Here, we describe a novel particle gel-agglutination technique for simplified visualization of the amplified products. MATERIALS AND METHODS: Biotinylated primers were used to amplify HPA-1, -2, -3, -4, -5, -6, and -15, and the PCR products were incubated with streptavidin particles. Fluorescein isothiocyanate (FITC)-labelled primers [amplifying a fragment of the human growth hormone (HGH) gene] and anti-FITC-coated particles were used as internal controls. Agglutination of the particles in or on top of the gel indicated specific amplification. A total of 100 samples from blood donors was tested by using this new technique and a standard PCR-SSP protocol. RESULTS: The use of biotinylated sequence-specific primers resulted in PCR products that agglutinated streptavidin particles, and the FITC-labelled HGH primers led to agglutination of anti-FITC-coated particles. Negative reactions were clearly distinguishable from positive reactions. The results of the particle gel agglutination method were in concordance with those of the electrophoretic visualization in all cases tested. CONCLUSIONS: The new particle agglutination method is reliable and easy to use.

Agglutination Tests↗
PubMed2004

Impact of the Gulf war on congenital heart diseases in Kuwait.

BACKGROUND: There has been concern over the increase in the number of babies born with congenital heart diseases (CHD) in Kuwait after the Gulf War. METHODS: We evaluated retrospectively the number of Kuwaiti infants who were diagnosed to have CHD within the first year of life. The comparison was made between those presented from January 1986 to December 1989 (preinvasion) and those presented after the liberation of Kuwait (from January 1992 to December 2000). The number of cases was considered per 10,000 live births in that year. RESULTS: The numbers of cases were 2704 (326 before the invasion and 2378 after liberation). The mean annual incidence of CHD was 39.5 and 103.4 (per 10,000 live births) before and after the Gulf War, respectively (P<0.001). There was an increase in the number of babies with CHD during the immediate 3 years postliberation with a relative reduction in the trend from 1995 to 2000, in some types of CHD. CONCLUSIONS: In our series, there was an increased incidence of CHD almost immediately following the end of the Gulf War period. The cause of this increase remains relatively obscure. Environmental pollution may be a contributing factor; others such as possible psychological trauma remain subject to speculation.

Biological Warfare↗
PubMed2004

[Aquired immune hemolytic anemias].

Aquired immune hemolytic anemias are classified in autoimmune hemolytic anemia (AIHA) of warm type, cold agglutinine disease, paroxysmal cold hemoglobinuria, drug-induced immune hemolytic anemia, and paroxysmal nocturnal hemoglobinuria. The autoantibodies in AIHA of warm type react most strongly at 37 degrees C (warm autoantibodies). They are of the IgG, less commonly of the IgM and IgA classes. The cause of autoimmunization remains obscure in 50% of the patients (idiopathic AIHA). In the remaining cases, the AIHA is associated with other diseases. Corticosteroids are the mainstay of therapy, but most patients with AIHA of warm type require additional treatment with azathioprine or other drugs. Cold agglutinins are the cause of hemolysis in about 10% of patients with AIHA. Paroxysmal cold hemoglobinuria (Donath-Landsteiner) is less common and occur in children following infections. Drugs are the cause of hemolysis in about 10% of all cases with AIHA. The true incidence of alloimmune hemolytic anemias including neonatal immune hemolytic anemias is unknown. The paroxysmal nocturnal hemoglobinuria is rare. It is caused by complement activation due to aquired membrane defects.

Adult↗