[Determination of STREM-1 level in synovial fluid for diagnosis of septic arthritis in children]

Triggering receptors expressed on myeloid cells i.e soluble triggering expressed on myeloid cells-1 [STREM-1] is inducible on monocyte/macrophages and neutrophils and accelerates tissue destruction by propagating inflammatory responses in disease related to bacterial infections. The aim of this study was to investigate the role of STREM-1 in the synovial fluid to identify septic arthritis from aseptic ones. A cross sectional study [2007-2009] was conducted in the Pediatric and Orthopedic wards of Hazrat-e-Rasool Akram hospital, Tehran . Synovial fluid was aspirated in 53 cases with arthitis and searched for diagnosis of bacterial arthritis by conventional diagnostic tests. About 0.5-3cc of synovial fluid was stored at -70°C, and quantification of STREM-1 was done in 53 synovial fluid samples [Quantikine, R and D systems, USA] by EIA; results were compared between septic and aseptic arthritis. Septic arthritis was detected in 49% [26/53] and aseptic arthritis in 51%[27/53]. Positive synovial fluid culture was detected in 20.3%, and positive latex particle agglutination for bacteria was found in 8.5%. Positve direct smear was obtained in 10.5% of the cases. Cut off level 825 pg/ml for SF-STREM-1 yielded 50% sensitivity, 70% specificity, 64% Positive Predictive Value [PPV], and 64%, Negative Predictive Value [NPV]. Poor agreement was seen between SF -STREM-1 levels and positive culture [p value: 0.037; Kappa=0.28]. The area under the ROC curve for discriminating between septic and aseptic arthitis was 0.603 [95% CI; 0.757-0.448, p = 0.1]. SF-STREM-1 level with cutoff 825pg/ml had 50% sensitivity, and 70% specifity in discriminating between proved cases with septic arthitis from aseptic ones. Searching for bacterial antigens in synovial fluid [Latex Particle Aagglutination test] and synovial fluid -STREM-1 level could potentially assist clinicians in better diagnosis of septic arthitis if added to the conventional tests including smear and routine analysis of synovial fluid. It might prevent unnecessary empiric antibiotic theray in children with arthritis. In clinical decision making; randomized studies on the potential synovial fluid - STREM-1 -level guided antimicrobial therapy in bacterial arthritis would be useful.

Evaluation of humoral immune function in patients with bronchiectasis

Bronchiectasis is a chronic debilitating condition characterized by abnormal dilated thickwalled bronchi. To investigate humoral immune function in bronchiectatic patients, this study was performed. Forty patients with established diagnosis of bronchiectasis, who were referred from two tertiary care pulmonology centers in Tehran, were investigated in this study. Immunoglobulin isotypes concentrations and IgG-subclasses were measured by nephelometry and enzymelinked immunosorbent assay [ELISA] methods, respectively. All patients received unconjugated pneumococcal vaccine, and blood samples were taken before and 21 days after vaccination. Specific antibodies against whole pneumococcal antigens were measured using the ELISA method. Fifteen [37.5%] out of 40 patients were diagnosed to have defects in antibody mediated immunity including 5 [12.5%] patients with immunoglobulin class deficiency [2 with common variable immunodeficiency and 3 with IgA deficiency], 3 [7.5%] with IgG subclass deficiency and 7 [17.5%] patients had Specific antibody deficiency [SAD] against polysaccharide antigen despite normal levels of serum immunoglobulins and IgG subclasses. Our study along with several other studies confirmed that all patients with bronchiectasis should undergo thorough immunological evaluation in order to identify the presence of the underlying immunologic defect. This evaluation should include serum immunoglobulins, IgG subclasses concentrations and also determination of serum antibodies against pneumococcal antigens. Early diagnosis and appropriate treatment will prevent the subsequent complications and improve quality of life of affected individuals

Presence of idiopathic thrombocytopenic purpura and autoimmune hemolytic anemia in the patients with common variable immunodeficiency

Common Variable Immunodeficiency [CVID] is a heterogeneous group of disorders characterized by hypogammaglobulinemia and an increased susceptibility to recurrent infections as well as autoimmunity and malignancies. Idiopathic Thrombocytopenic Purpura [ITP] and Autoimmune Hemolytic Anemia [AIHA] are two autoimmune disorders which may be seen in association with CVID. Among 85 CVID patients, seven cases had ITP and/or AIHA [8%]. Four of these patients had one or more episodes of ITP, one patient had AIHA, and two patients had both ITP and AIHA [Evans syndrome]. Almost, all patients experienced chronic and recurrent infections mostly in respiratory and gastrointestinal systems during the course of the disease. Among the seven patients, five presented their underlying disease with recurrent respiratory and/or gastrointestinal tract infections, while in two remaining patients, CVID was presented with ITP. Three patients died until now; two because of hepatic failure and one due to pulmonary hemorrhage. As CVID is prone to autoimmune disorders, it should be considered as a differential diagnosis of adult-onset ITP and possibly in children. Chronic and recurrent ITP, especially in the presence of propensity to respiratory and gastrointestinal infections mandate the evaluation for an underlying immune dysregulation such as CVID

Autoimmune lymphoproliferative syndrome: meticulous care for diagnosis

Autoimmune lymphoproliferative syndrome [ALPS] is a prototypic disorder of abnormal lymphocyte homeostasis. In the September 2005 issue of The Iranian Journal of Allergy, Asthma and Immunology, a patient with clinical features consistent with ALPS was described. Although the clinical presentation was in favor of ALPS, a precise diagnosis needed more laboratory evaluations

Dificient expression of brouton's tyrosine kinase in monocytes from x linked agmmaglobulinemia as evaluated by a flow cytometric analysis and its clinical application to carrier detection

The B-cell defect in X-linked agammaglobulinemia [XLA] is caused by mutations in the gene for Bruton's tyrosine kinase [BTK]. BTK mutations result in deficient expression of BTK protein in peripheral blood monocytes. Using the anti-BTK monoclonal antibody [48-2H], a flow cytometric analysis of intra cytoplasmic BTK protein expression in monocytes was performed to identify Iranian patients with XLA phenotype. To examine the possible identification of XLA patients and female carriers by this assay, we studied 13 XLA families. The flow cytometric assay showed deficient expression of the BTK protein in 12 [92%] families. One patient exhibited a normal level of BTK expression. The cellular mosaicism of BTK expression in monocytes from obligate carriers was clearly shown in 9 of 12 [75%] families. The results suggested that most XLA patients have deficient expression of the BTK protein; therefore we conclude that deficient expression of BTK protein can be evaluated by a flow cytometric assay