Autoimmune thrombocytopenia: flow cytometric determination of platelet-associated CD 154/CD40L and CD40 on peripheral blood T and B lymphocytes: their role in immunological aspects of the disease

The CD40-CD40L system has pleiotropic effects in a variety of cells and biological processes including immune response. Within the immune system, these molecules represent a critical link between its humoral and cellular arms. Immune or idiopathic thrombocytopenic purpura [ITP] is an autoimmune disorder characterized by antibody-induced platelet destruction and clearance because of anti-platelet autoantibodies, which bind to circulating platelets resulting in their destruction by the reticuloendothelial system. Despites its clinical importance, the diagnosis of ITP is one of exclusion, thus, inevitably associated with potential difficulties, CD40 is a cell surface receptor that belongs to the tumor necrosis factor- receptor [TNF-R] family, and that was first identified and functionally characterized on B lymphocytes. CD40-ligand [CD40L/CD154], a member of the TNF superfamily is a cell membrane molecule expressed on activated CD4+ T lymphocytes and is essential for the T cell-dependent activation of B lymphocytes. Therefore it is now thought that CD40-CD40L interactions play a more important role in ITP immune regulation. The expressions of CD154 and CD40 on peripheral blood [PB] T and B lymphocytes, respectively, were measured using the technique of flow cytometry. An antigen-specific assay for platelet-associated antibody CD150 [CD40L] on CD4+ T lymphocytes and for CD40 on CD 19+ B lymphocytes was tested in 30 children patients with acute ITP, 30 adult patients with chronic ITP, and in 20 age-and sex-matched healthy controls. The results of this showed that the expressions of CD4+CD154+ and of CD4+CD154+/CD4+ on PB T lymphocytes, and of CD19+CD40+ and of CD19+CD40+/CD19+ on PB B lymphocytes were significantly higher in acute and chronic ITP patients compared to controls, and in acute patients compared to chronics [p<0.001]. CD40-CD40L interaction plays and important role in the pathology of certain autoimmune diseases. ITP is an autoimmune disease characterized by increased platelet destruction caused by anti-platelet auto antibodies, which mainly target a platelet surface antigen. It is speculated that platelet-associated CD154 is competent to induce the CD40-dependent proliferation of B lymphocytes. Therefore, platelet-associated CD154 expression is increased in ITP patients and is able to drive the activation of autoreactive B lymphocytes in this disease. These findings are particularly useful for clarifying the pathogenic process in ITP patients and for developing a therapeutic approach that blocks pathogenic anti-platelet antibody production. Blockade of the CD40/CD154 signal is a potential immunomodulatory strategy for T-cell mediated diseases, and many findings suggest that CD40/CD154 blockade therapy is potentially effective for ITP through selective suppression of autoreactive T and B lymphocytes to platelet antigens

Non-invasive versus invasive assessment of pulmonary artery branches in pediatric patients with tetralogy of fallot

This study was based on two issues, the 1[st] one was that the pulmonary artery anatomy is the key factor that determines the type of surgical treatment required in tetralogy of Fallot [TOF]. The 2[nd] one was that many studies showed a good correlation of the echocardiographic measurements of cardiac structures with the angiographic and pathological findings. So, the aim of this work was to evaluate the reliability of echocardiography in assessment of the pulmonary blood flow status in pediatric patients with TOF. Only patients with the usual anatomy of TOF were included in this study. It included 68 patients distributed into two groups; group I included 18 patients [26.5%], their mean age was 29.1 +/- 21.4 months and their mean weight was 11.2 +/- 2.1 kg. Group II included 50 patients [73.5%], their mean age was 34 +/- 23 months, their mean weight was 12.6 +/- 4.1 kg. We tested the accuracy of the 2-D echocardiography in measuring the right and the left pulmonary arteries [RPA and LPA] and compared them to the measurements taken by angiography [group I] as well as to the measurements taken at surgery [group II]. The standard deviation unit [Z value] for the RPA and LPA was calculated as well as the pulmonary artery index [PAI] from echocardiographic and angiographic measurements for group I and from echocardiographic and surgical measurements for group II. The results showed that For group I patients, there was statistically significant difference in the measurements of RPA and LPA and consequently the calculated Z value and the PAI between echocardiographic and angiographic modalities. Similarly, group II patients demonstrated a statistically significant difference in the measurements of RPA and LPA and consequently the calculated Z value and the PAI between the echocardiographic and surgical methods. Despite these significant differences found in both groups, the echocardiographic measurements correlated well with the angiographic measurements in group I as well as with the surgical measurements in group II. The differences detected between the echocardiographic and the surgical measurements were less than the differences detected between the echocardiographic and angiographic measurements. This mostly related to our earlier experience in measurement of the pulmonary artery branches using 2-D echocardiography in group I, but with time, we got more experienced in this issue, thus the differences in measurements were minimized in group II. The maximum difference between the echocardiography and surgery for the RPA and LPA was 2.1 mm and 2.0 mm and the mean difference was 0.71 +/- 0.45 and 0.63 +/- 0.46 mm respectively. Our results reflect a clinically acceptable accuracy of 2-D echocardiography in estimation of the pulmonary artery branches and thus surgical management of TOF, guided by echocardiography alone, can be confidently performed in selected infants and children. Cardiac catheterization should be reserved for patients in whom the echocardiographic measurements are not fully certain or suggest association of cardiovascular malformation

Correlation study between cord blood trace elements and anthropometric measures of the newborn

This work was designed to assess the serum zinc and copper levels in pregnant Egyptian ladies at delivery and in their corresponding offspring as well as to study the effects of these elements on intrauterine fetal growth. Thirty full term small for gestational age neonates [SGA] were studied together with their mothers at delivery. They were compared to thirty eight full term appropriate for gestational age [AGA] neonates as well as their mothers. Mothers of both groups of studied neonates were compared to 20 non pregnant ladies as regards serum zinc and copper level. All cases and controls were subjected to detailed history taking from mothers and all deliveries were attended. All babies were examined to exclude acute and chronic complications. Anthropometric measurements were taken at birth. Laboratory investigations including assessment of serum zinc and copper levels by atomic absorption spectrophotometry were performed. The results proved that serum zinc levels were significantly lower in the group of SGA babies as well as their mothers than the group of AGA babies and their corresponding mothers. Similarly, both groups of delivered mothers had significantly lower zinc level than non pregnant ladies. Study of the copper levels in mothers and their neonates showed a tendency to increased levels beyond the normal upper limit in the group of both mothers of SGA and AGA babies with no such increase in their neonates. Our study confirmed that zinc status of mothers during pregnancy strongly affects the intrauterine growth of fetuses. This effect was mainly on weight, resulting in retardation of their growth in cases of mothers who suffered form hypozincemia. The end result was delivery of small for gestational age babies