While type I IFNs were discovered in the 1950s, it was not until 2003 that the first type III IFNs, namely, IFN lambda 1 (IFNL1), lambda 2 (IFNL2), and IFN lambda 3 (IFNL3), were described [1,2].
IFNL1 through IFNL3 have a high degree of sequence similarity with 72% to 96% amino acid conservation with IFNL2 and IFNL3 being most closely related.
Alavian et al., "The prevalence of hepatitis C virus core amino acid 70 substitution and genotypes of polymorphisms near the IFNL3
gene in iranian patients with chronic hepatitis C," Hepatitis Monthly, vol.
In 2009, single nucleotide polymorphisms (SNP) of the IFNL3 gene (rs12979860) were related to natural clearance of HCV.
(7) Nonetheless, some patients still experience treatment failure due to on-treatment viral breakthrough or relapse after cessation of therapy, possibly attributed to unknown host and viral factors, such as IFNL3 gene polymorphism.
(IL28B) and IFNL4 polymorphisms are associated with treatment response in Thai patients infected with HCV genotype 1, but not with genotypes 3 and 6.
Clinical pharmacogenetics implementation consortium (CPIC) guidelines for IFNL3
(IL28B) genotype and PEG interferon-a-based regimens.
Objective: To describe the risk factors for infection, complications, treatment received and response in Puerto Ricans with HCV attending gastroenterology clinics at UPR-MSC, and the prevalence of single nucleotide polymorphisms (SNPs) in IFNL3 and IFNL4 in this population.
The SNP frequencies (n = 239) of IFNL3 locus rsl2979860 were 27% (C/C), 50% (C/T), and 23% (T/T), and for rs8099917 were 46% (T/T), 47% (T/G), and 7% (G/G).
IFN-[lambda]3 is a protein product of the IFN-[lambda]3 gene (IFNL3
) clustered on chromosome 19 (19q13.13 region, contig AC011445.6).
(39) We were also not able to assess genetic associations between interferon-lambda 3 (IFNL3
, previously called IL28B), and which is known to be associated with HCV clearance.
(1) Human single nucleotide polymorphisms near the gene for interferon-[lambda]3 (IFNL3
; formerly known as 1L28B) were also recently associated with spontaneous HCV clearance and sustained response to interferon-based therapy.