Evidence of inherited susceptibility of increased streptococcal adherence to pharyngeal cells of children with rheumatic fever.
The study included the members of 15 families, each having more than one sibling affected by rheumatic fever (RF). All the rheumatic individuals showed the sequelae of rheumatic carditis, but on clinical and laboratory evidence, the disease was inactive. Thirty normal unrelated individuals, having no rheumatic first-degree relatives, were studied as controls. The following investigations were carried out for all members: (1) history and clinical examination, (2) routine investigations of diagnosis, (3) HLA typing using 9-A, 15-B, 6-DR antigens, (4) adherence of group A streptococci to pharyngeal cells, an in vitro adherence assay. There were two types of strains; five RF-associated strains and two RF-unassociated strains. Statistical and genetic analysis revealed: (1) no significant difference between adherence of RF-associated and unassociated strains amongst controls; (2) significant increased avidity for adherence of RF-associated strains amongst rheumatic siblings compared to normal siblings and controls. There was no significant difference between the three groups using RF-unassociated strains; (3) HLA-haplotype concordance and 'N' measure showed that the avidity for adherence is probably inherited; (4) lod scores for linkage suggest a dominant susceptibility gene(s) closely linked to HLA and segregating in multiplex families.
Hafez
M
M
Department of Paediatrics, Faculty of Medicine, Mansoura University, Egypt.
el-Battoty
M F
MF
Hawas
S
S
al-Tonbary
Y
Y
Sheishaa
A
A
el-Sallab
S
S
el-Morsi
Z
Z
el-Ziny
M
M
Hawas
S E
SE
D001422:Bacterial Adhesion; D003277:Contraceptives, Oral, Combined; D005190:Family; D005192:Family Health; D006680:HLA Antigens / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D008126:Lod Score; D010375:Pedigree; D010614:Pharynx / Q000166:cytology* / Q000382:microbiology; D012213:Rheumatic Fever / Q000235:genetics*; D013297:Streptococcus pyogenes / Q000502:physiology*
D003277:Contraceptives, Oral, Combined; D006680:HLA Antigens