Relation between anti-Porphyromonas gingivalis antibody titers and HLA-DRB1 neutral alleles in individuals with rheumatoid arthritis.

OBJECTIVE: This study aimed to determine the relation between titres of anti-Porphyromonas gingivalis (P. gingivalis) antibody and rheumatoid arthritis (RA) HLA-DRB1 susceptibility region associated with shared epitope (SE) using the Gregersen's and de Vries's classification methods. MATERIAL AND METHODS: In this cross-sectional study, results of immunoglobulin G1 (IgG1) and immunoglobulin G2 (IgG2) anti-P. gingivalis antibodies, anti-citrullinated protein antibodies (ACPA), diagnosis for RA, and periodontal disease (PD), and a genetic study of the HLA DRB1 region were obtained from 50 patients with RA and 50 control individuals. RESULTS: Anti-P. gingivalis antibody levels and PD parameters were similar in control and RA groups. Anti-P. gingivalis antibodies were not associated with SE or ACPA. There was no association between ACPA and SE. However, de Vries' classification in RA patients revealed an association between the HLA DRB1 neutral alleles and higher titres of anti-P. gingivalis antibodies as follows: IgG1 anti-P. gingivalis ≥ 1:400 (p = .039); IgG2 anti-P. gingivalis ≥ 1:400 with neutral/neutral genotype (N/N), being exclusive for RA (p = .008); and IgG2 anti-P. gingivalis ≥ 1:200 and N/N (p = .016). CONCLUSIONS: Although no association was found between SE and anti-P. gingivalis antibodies; according to the de Vries' classification, there was an existing association between HLA DRB1 neutral alleles, with high titres of IgG anti-P.gingivalis antibodies for RA, focussing on novel associations between P.gingivalis and RA.

Hereditary leiomyomatosis and renal cell cancer syndrome: identification and clinical characterization of a novel mutation in the FH gene in a Colombian family.

Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome (HLRCC) is a rare disease and since the first report, it has been found in just over 200 families approximately, around the world (Smit et al. in Clin Genet 79:49-59, 2009). Patients in Colombia or in Latin America have not been described, as far as we know. HLRCC is inherited in an autosomal dominant manner, and it is caused by heterozygous germline mutations in the FH gene, which encodes the fumarate hydratase enzyme. It is characterized mainly by the appearance of cutaneous and uterine leiomyomas, and an early-onset, aggressive form of type 2- papillary renal cell carcinoma (Smit et al. in Clin Genet 79:49-59, 2009; Schmidt and Linehan in Int J Nephrol Renovasc Dis 7:253-260, 2014]. We report a Colombian family with HLRCC syndrome, with a novel mutation in FH gene (c.1349_1352delATGA) in which cutaneous leiomyomas have not been found, but other clinical manifestations such as type 2- papillary renal cell carcinoma, uterine leiomyomas and rare tumors were present. This investigation constitutes the first report of HLRCC syndrome in Colombia, and probably in Latin America.