Russian registry of patients with cystic fibrosis: lessons and perspectives

Abstract

A registry of patients with cystic fibrosis (CF) of the Russian Federation has been compiled annually since 2011. Analysis of the national registry with large amounts of clinical and laboratory data helps understand changes in demographic indicators, plan measures to improve the quality of medical care and evaluate their effectiveness.Aim. To analyze health status of patients with cystic fibrosis in the Russian Federation and the dynamics of key clinical and laboratory parameters from 2011 to 2021. Methods. The health status of CF patients was assessed using the registry data from 2011 to 2021.Results. The analysis revealed an increase in the total number of patients from 1,026% in 2011 to 3,969 in 2021, in the number of patients identified by neonatal screening from 28.8% to 53.5%, and in coverage by genetic testing from 91.8 to 93.6%. At the same time, the number of mutations detected dropped from 80 to 90.5% and the number of patients with unidentified mutations decreased from 9.5 to 3.2%. The mean age at diagnosis of cystic fibrosis did not change (3.3 ± 5.5 in 2011 and 3.1 ± 6.2 in 2021) despite an increase in the number of patients diagnosed through neonatal screening. There was a difference in M ± SD age from 2011 to 2021 (11.5 ± 8.9 in 2011 and 14 ± 9.8 in 2021). The proportion of adult patients was 24.95% in 2011 and 27.4% in 2021. The therapy changed over 11 years - the number of courses of intravenous therapy decreased from 70.9 to 36.4%, the number of patients using inhaled antipseudomonal therapy expanded to 45%, the number of patients using hypertonic sodium chloride solution expanded from 8.7 to 70.7%, the use of glucocorticoids decreased. The targeted therapy was introduced in 2018, and the number of patients receiving pathogenetic drugs is growing.Conclusion. The observed changes are indicative of the health status of Russian patients with cystic fibrosis. Analysis of registries helps improve the organization of medical care, predict and implement sanitary and epidemic measures, plan therapy, and assist the regions in organizing outpatient monitoring and microbiological control. The registry is analyzed to organize health care for adult patients.

L138ins Variant of the CFTR Gene in Russian Infertile Men

“…In general, the allele frequency (AF) of this genetic variant in Russian CF patients is 0.0153, but it obviously depends on age, e.g., in children (under 18 years) it is 1.43%, in adults-1.83% [11]. The slightly higher frequency of this variant in CFTR in adult patients is probably due to the milder phenotype of CF in its carriers.…”

“…According to the Registry of Russian Patients with Cystic Fibrosis [11], the L138ins variant is one of the common genetic variants of the CFTR gene in Russian patients with CF (Table 4). a frequency of more than 0.10% are presented; adopted from [11]).…”

“…The L138ins variant (c.413_415dupTAC, rs397508679, p.(Leu138dup)) is a mild pathogenic variant that is classified as a class IV-V mutation in the CFTR gene based on its mechanism of pathogenicity. This variant is one of the most common in CF patients of Eastern European origin, especially in the Volga-Ural region [11,16]. The allele frequency (AF) of the L138ins variant in Russian CF patients was 0.0153, as documented in the Register of Cystic Fibrosis Russian Patients (2018); however, this frequency varied from 0 to 0.028 depending on the region within the Russian Federation [11].…”

“…The frequency and spectrum of the CFTR gene variants vary significantly in different regions of the world. In a number of countries, including the Russian Federation, the most frequently observed pathogenic variant in the CFTR is c.1521_1523delCTT (F508del; p.(Phe508del)) [11][12][13][14]. In addition, Russian populations frequently carry pathogenic variants, including CFTRdele2,3(21kb), E92K, 1677delTA, 3849+10kbC>T, 2143delT, W1282X, N1303K, and G542X, with an allele frequency (AF) greater than 1% in patients, diagnosed with CF [12][13][14][15].…”

“…This variant is one of the most common in CF patients of Eastern European origin, especially in the Volga-Ural region [11,16]. The allele frequency (AF) of the L138ins variant in Russian CF patients was 0.0153, as documented in the Register of Cystic Fibrosis Russian Patients (2018); however, this frequency varied from 0 to 0.028 depending on the region within the Russian Federation [11]. Therefore, the L138ins variant can be classified as one of the most frequently observed pathogenic variants in the CFTR gene in Russian CF-patients.…”