TNF and lymphotoxin-alpha polymorphisms associated with common variable immunodeficiency: role in the pathogenesis of...

A subgroup of common variable immunodeficiency (CVID) patients have distinct clinical features, particularly granulomata splenomegaly, characteristic blood lymphocyte phenotype, and elevated circulating TNF levels. To investigate the genetic basis for this phenotype, 150 CVID patients and 200 controls were genotyped for six biallelic TNF and lymphotoxin-alpha (LT alpha) polymorphisms and eight class I and II HLA loci using PCR and sequence specific primers (PCR-SSP) sequence-specific primers. Clinical and immunophenotypic data were collected for 90 patients to examine associations with CVID patient subgroups. The presence of granulomata (22% of patients) was strongly associated with splenomegaly, T and B lymphopenia, reduced CD4+ CD45RA+ T cells, and CD8+ CD57+ lymphocytosis, confirming the concept of a subgroup of patients with distinct clinical and laboratory features. The uncommon TNF +488A allele was strongly associated with this subgroup (p = 0.0005). The association between "granulomatous" CVID and TNF +488A was independent of HLA class I and II associations. We postulate that the presence of the TNF +488A allele, or alleles in linkage disequilibrium with it, contributes to the high levels of TNF and granulomatous complications characteristic of this subgroup of patients.