Biomedical subjects

F el-Shennawy

Publications and source records attributed to F el-Shennawy.

9 recordsLinked to original sources

PubMed1991

Immunogenetic susceptibility for post-schistosomal hepatic fibrosis.

In 19 children with hepatic fibrosis as the result of continued schistosomiasis mansoni and 20 children without hepatic fibrosis, the following studies were carried out: HLA antigen typing for 30 antigens, immune response of T lymphocytes to schistosome antigen by measuring DNA synthesis evidenced by 3H-thymidine uptake, and measurement of total OKT3+, OKT4+, and OKT8+ cells using monoclonal antibodies. Patients with hepatic fibrosis were mostly high responders in contrast with those without fibrosis. High immune response and susceptibility to post-schistosomal hepatic fibrosis were associated with a high frequency of A2 and B12 antigens and a lack of DR2 antigens, while low response was associated with the presence of the DR2 antigen. The T4+:T8+ ratio showed increased suppressor proportions in patients with low immune response and/or with no hepatic fibrosis. We suggest an immunogenetic susceptibility for post-schistosomal hepatic fibrosis, probably controlled by HLA-linked genes via the suppressor T cells.

Adolescent↗

PubMed1990

Immunogenetic study of the response to streptococcal carbohydrate antigen of the cell wall in rheumatic fever.

An immunogenetic study of the response to streptococcal carbohydrate antigen of the cell wall was carried out on members of 15 multiplex families each having more than one sib affected with rheumatic heart disease. They comprised 30 parents and 61 sibs (32 with rheumatic disease and 29 without). Fifty healthy unrelated subjects served as controls. A history was taken and clinical examination carried out. Rheumatic activity was determined and HLA typing was carried out for nine A antigens, 15 B antigens, and six DR antigens. The immune response of lymphocytes to streptococcal polysaccharide antigen of the cell wall of group A beta haemolytic streptococci in vitro was studied by tritiated thymidine uptake. The results were statistically and genetically analysed. It was found that (a) all subjects with rheumatic disease were highly responsive to the streptococcal polysaccharide antigen of the cell wall, the sib pairs being mostly HLA identical; (b) all low responders had no rheumatic disease and their phenotypes were mostly different from those of the rheumatic member of their sib pair; (c) correlation of immune responsiveness (high or low) between HLA-identical sibs was significant, but insignificant between haplotype identical and non-identical sibs; (d) the gene responsible for high responsiveness to the streptococcal polysaccharide antigen of the cell wall is recessive and closely linked to HLA. In conclusion, it was found that exposure to pharyngeal infection with group A beta haemolytic streptococci may lead to acute rheumatic fever in those with an inherited recessive gene responsible for high responsiveness to the streptococcal polysaccharide antigen of the cell wall.

Adolescent↗

PubMed1988

Immune regulation dysfunction in chronic persistent hepatitis.

The study included 19 children diagnosed clinically, biochemically, and by liver biopsy as having chronic persistent hepatitis. The following investigations were carried out: 1. detection of total T-lymphocytes, T-helper, and T-suppressor cells using monoclonal antibodies (OKT3, OKT4 and OKT8); 2. determination of HLA-A, B and DR antigens using the microcytotoxicity technique. The results were analysed in comparison with data from a normal control group. There are several important findings. First, low total T-lymphocytes with increased proportion of suppressor cells (P less than 0.001). Second, strong association between HLA-A1 antigen and CPH (Fisher exact = 0.000022). Third, significant association between the immunoregulatory dysfunction and A1 antigen (Fisher exact = 0.033). This observation suggests that a genetic component may influence susceptibility to CPH through an increased suppressor response.

Adolescent↗

PubMed1987

Inherited immunoregulatory dysfunction in extrinsic bronchial asthma.

We studied 119 members of 22 asthmatic multiplex families. Included were: 44 parents (seven were asthmatics), 48 asthmatics (23 were undergoing an attack at the time of sampling), and 27 normal siblings. The following investigations were carried out on all subjects: 1) detection of total T lymphocytes, helper cells, and suppressor cells, using monoclonal antibodies (OKT3, OKT4, and OKT8), 2) study of nonspecific T-lymphocyte blast transformation induced by PHA, and 3) HLA-A, B, and DR antigen determination using the microcytotoxicity technique. The results were compared with normal ranges and data for a normal group and statistically and genetically analyzed. They indicate that: 1) the number of T cells was low in asymptomatic asthmatics and normal in asthmatics in attack; 2) there were fewer helper and normal suppressor cells (that is, a low H:S ratio) in asymptomatic asthmatics, and a normal amount of helper and suppressor cells (a normal H:S ratio) in those experiencing an attack; 3) there was a percentage of lymphocyte transformation in both groups of asthmatics; 4) whereas the T-helper cells increased, there was no change in the number of suppressor cells during an attack, which points to deficient function of suppressor cells; 5) the disorder is inherited and the gene controlling this dysfunction is HLA-linked and probably dominant.

Adolescent↗

PubMed1987

Presumptive evidence for an immunosuppressor susceptibility gene, linked to HLA, in rheumatic fever.

In a study of rheumatic carditis, 135 members of 21 multiplex families have been investigated, along with 60 normal unrelated control individuals. Circulating T-lymphocytes were reduced (as a percentage of total blood mononuclear cells) in all 'rheumatic' individuals, in 7 of 40 normal parents, and in 8 of 49 normal sibs. An immune response characterized by an increase in the proportion of suppressor T cells occurs in most individuals affected by rheumatic carditis and this change persists for a long time. Genetic analysis revealed three important points: 1. increased HLA haplotype sharing amongst the affected sib-pairs; 2. the possibility of using low circulating T-cell percentage as a marker of susceptibility; 3. presumptive evidence for a recessive susceptibility gene linked to HLA and responsible for the suppressor cell response.

Female↗

PubMed1987

Immunogenetic aspects of febrile convulsions.

Thirty-nine mentally normal unrelated children diagnosed as having febrile convulsions were included in this study. The following have been carried out: (a) detailed anamnesis and clinical examination; (b) cerebrospinal fluid investigation; (c) EEG examination between attacks; (d) HLA-antigen determination; (e) estimation of serum IgA, IgG, IgM; and (f) counting of percent spontaneous E-rosette formation. The results were statistically compared to normal Egyptian controls. The results could be summarised as follows. (1) Only HLA-B5 antigen frequency is high among patients (chi 2c = 19.1, P less than 0.0001). Relative risk is 4.4 which shows significant association (WY2 = 29.145, P less than 0.0001) and etiologic fraction equals 0.377. (2) The means of IgA and E-rosette in the patients were significantly low (t = 3.46, P less than 0.01 and t = 3.92, P less than 0.001, respectively), (3) HLA-B5 is the only antigen with high frequency among the two groups of patients with low IgA and E-rosette (chi 2c = 11.9 and 18.2, respectively). (4) There is a significant association between B5 and low IgA (P less than 0.05) but not with low E-rosette (P greater than 0.05). The suggestion is that the genetic control of febrile convulsions is in linkage disequilibrium with HLA-B5, low IgA and low total T-cells. This altered immune function in otherwise normal children with febrile convulsions may predispose them to acute infections and high fever which precipitate convulsions.

Child↗

PubMed1986

HLA antigens in multiplex families with isolated congenital heart disease.

Twelve multiplex families with isolated congenital heart diseases (CHD) were included in the study. In 9 families the types of CHD in the living sibs were concordant and in the other 3 were discordant. All families were subjected to the following: (1) Pedigree construction, (2) clinical examination of the parents, affected and unaffected sibs, (3) investigations of patients, to establish the diagnosis, (4) chromosomal analysis for the patients, (5) HLA antigen typing for the parents, affected and unaffected sibs for 9 antigens at the A locus, 15 at B and 6 at the DR locus. The results can be summarized as: (a) sibs with two different types of CHD showed identical haplotypes; (b) the segregation of haplotypes among disease sibpairs is inconsistent with Mendelian segregation; (c) increased frequency of concordant HLA haplotypes among diseased siblings; (d) Morton's exact test revealed that the data best fit a hypothesis of a recessive susceptibility gene, linked to HLA.

Disease Susceptibility↗

PubMed1985

HLA antigens and acute rheumatic fever: evidence for a recessive susceptibility gene linked to HLA.

From 60 probands with acute rheumatic fever (ARF), 19 multiplex families segregating for ARF were ascertained. The parents and rheumatic and normal sibs of the probands in these 19 families were also studied. HLA typing using the microlymphocytotoxic assay was then performed on the 60 unrelated probands, the multiplex families, and 234 unrelated controls using 23 antigens from the HLA-A and -B loci. The controls lacked a past history of ARF and were from the same geographic locality. Calculations of relative risk demonstrate an increase of HLA-B5 antigen in the 60 patients, but the result might not be significant from the point of view of multiple comparisons. Nevertheless, affected sib pairs from the multiplex families show 93% concordance for both or one HLA haplotype. A formal linkage analysis demonstrates that a recessive etiology is most likely (lod score of 3.3) with approximately 68% of cases being due to a gene closely linked to HLA and in linkage disequilibrium with HLA-B5. The remaining 32% of cases are due to other familial factors such as polygenic inheritance or common environmental factors. The results confirm a strong genetic predisposition to ARF and its heterogeneous nature in families.

Gene Frequency↗

PubMed1985

HLA-antigens and tuberculosis in the Egyptian population.

Peripheral blood lymphocytes from 42 unrelated Egyptian patients with tuberculosis and 156 healthy persons were HLA phenotyped for the A,B and DR loci using the NIH lymphocytotoxicity tests. Statistical analysis of the results showed that A2 and B5 had significantly increased frequencies among patients with tuberculosis compared with the controls. Patients with A2 had more severe disease than did patients without A2 and the number with B5 antigen was less than those without the antigen. This observation suggests that A2 and B5 may influence susceptibility to tuberculosis, but not the course of the disease. Furthermore, a linkage disequilibrium was found between A2 and B5 antigen among tuberculous patients, but their association bore no relation to the severity of the disease.

Adolescent↗