Izabela Nowak

Associations of killer cell immunoglobulin-like receptor genes with complications of rheumatoid arthritis

We investigated whether killer cell immunoglobulin-like receptor (KIR) genes are risk factor(s) for rheumatoid arthritis (RA) and its clinical manifestations. One hundred and seventy-seven RA patients and 243 healthy individuals were tested for the presence of 11 KIR genes using PCR-SSP method. The frequencies of KIRs in patients with RA were similar to the frequencies in controls. However, RA patients positive for KIR2DL3 and negative for KIR2DS3 had earlier disease diagnosis. Additionally, KIR2DL2 and KIR2DS2 were significantly more frequent among RA patients with extra-articular manifestations and in its subgroup with vasculitis than in controls and in patients without these complications. Furthermore, the frequencies of KIR2DS1 and KIR3DS1 were lower in patients without bone erosions compared with healthy individuals. Relationships between the presence or absence of autoantibodies (rheumatoid factor and anti-cyclic citrullinated peptide) and KIR frequencies were also evaluated, but no significant differences were observed. These results suggest that particular clinical manifestations of RA may have different genetic backgrounds with respect to KIR genotype.

Does the KIR2DS5 Gene Protect from Some Human Diseases

Background KIR2DS5 gene encodes an activating natural killer cell receptor whose ligand is not known. It was recently reported to affect the outcome of hematopoietic stem cell transplantation. Methodology/Principal Findings In our studies on KIR2DS5 gene associations with human diseases, we compared the frequencies of this gene in patients and relevant controls. Typing for KIR2DS5 gene was performed by either individual or multiplex polymerase chain reactions which, when compared in the same samples, gave concordant results. We noted an apparently protective effect of KIR2DS5 gene presence in several clinical conditions, but not in others. Namely, this effect was observed in ankylosing spondylitis (p = 0.003, odds ratio [OR] = 0.47, confidence interval [CI] = 0.28–0.79), endometriosis (p = 0.03, OR = 0.25, CI = 0.07–0.82) and acute rejection of kidney graft (p = 0.0056, OR = 0.44, CI = 0.24–0.80), but not in non-small-cell lung carcinoma, rheumatoid arthritis, spontaneous abortion, or leukemia (all p>0.05). In addition, the simultaneous presence of KIR2DS5 gene and HLA-C C1 allotype exhibited an even stronger protective effect on ankylosing spondylitis (p = 0.0003, OR = 0.35, CI = 0.19–0.65), whereas a lack of KIR2DS5 and the presence of the HLA-C C2 allotype was associated with ankylosing spondylitis (p = 0.0017, OR = 1.92, CI = 1.28–2.89), whereas a lack of KIR2DS5 and presence of C1 allotype was associated with rheumatoid arthritis (p = 0.005, OR = 1.47, CI = 1.13–1.92). The presence of both KIR2DS5 and C1 seemed to protect from acute kidney graft rejection (p = 0.017, OR = 0.47, CI = 0.25–0.89), whereas lack of KIR2DS5 and presence of C2 seemed to favor rejection (p = 0.0015, OR = 2.13, CI = 1.34–3.37). Conclusions/Significance Our results suggest that KIR2DS5 may protect from endometriosis, ankylosing spondylitis, and acute rejection of kidney graft.

Activating killer immunoglobulin-like receptor incompatibilities enhance graft-versus-host disease and affect survival after allogeneic hematopoietic stem cell transplantation.

Objectives:  Killer immunoglobulin‐like receptors (KIRs) regulate function of natural killer (NK) cells and a subset of T cells. In this study, we prospectively evaluated the impact of donor and recipient activating KIR genes on outcome of allogeneic hematopoietic stem cell transplantation (alloHSCT) for patients with hematological malignancies.

Association of the HLA‐G gene polymorphism with multiple sclerosis in a Polish population

In this study, three polymorphic sites in the HLA‐G gene: −725C>G>T, −716T>G and 14bpindel were genotyped. Significant differences were found between patients and controls in the alleles and genotypes for −725C>G>T and in three‐point haplotypes. We observed also a significant difference in the age of disease onset between patients positive and negative for 14bpins. The results suggest that single nucleotide polymorphisms in the promoter of the HLA‐G gene (mainly −725C>G>T), and 14bpindel, or some genetic marker in tight linkage disequilibrium with them are associated with multiple sclerosis.

Association of PTPN22 single nucleotide polymorphism with rheumatoid arthritis but not with allergic asthma.

PTPN22 gene encodes a lymphoid tyrosine phosphatase (LYP), an important negative regulator of T-cell responses. The 1858C>T (Arg620Trp) single nucleotide polymorphism (rs2476601) was found associated with autoimmune diseases, including rheumatoid arthritis (RA). Allergic diseases are similar to autoimmune diseases, by an exaggerated immune response to an antigen (allergen in this case) normally not invoking such response in healthy individuals. We investigated whether polymorphism 1858C>T in PTPN22 gene is associated with susceptibility to allergic asthma and RA in a Polish population. PTPN22 was genotyped in 173 patients with RA, in 198 patients with allergic asthma, and in 543 controls using PCR-RFLP. The patients with RA differed from healthy controls in frequencies of PTPN22 1858C>T alleles (P=0.0004; odds ratio (OR), 1.8; 95% CI, 1.33–2.55) and genotypes (P=0.0009). Strong associations of 1858T allele with RA limited to joints (0.21 vs 0.12, P=0.0002; OR, 2.1; 95% CI, 1.44–3.00), with erosive disease (0.20 vs 0.12, P=0.0003; OR, 1.92; 95% CI, 1.34–2.71), with a lack of rheumatoid factor (RF; 0.23 vs 0.12, P=0.0008; OR, 2.29; 95% CI, 1.44–3.63), and weak association with the presence of RF (0.17 vs 0.12, P=0.02; OR, 1.6; 95% CI, 1.10–2.40) in comparison with healthy controls were observed. Very strong association of 1858T allele (P<0.0001; OR, 2.72; 95% CI, 1.9–3.9) and T phenotype (P<0001; OR, 3.2; 95% CI, 2.1–4.9) with antibodies to cyclic citrullinated peptide (CCP) was found. When patients with allergic asthma were typed for PTPN22 1858C>T polymorphism, no difference with control was found. Subdivision of patients into those with mild, moderate, or severe asthma did not reveal any associations. In conclusion, we confirmed associations between several clinical manifestations of RA and PTPN22 1858T allele. However, no association with 1858C>T polymorphism was found for susceptibility to allergic asthma or for severity of the disease.

KIR2DL2/S2 and HLA-C C1C1 genotype is associated with better response to treatment and prolonged survival of patients with non-small cell lung cancer in a Polish Caucasian population

Non-small cell lung carcinoma (NSCLC) is a multifactorial disease influenced by both environmental and genetic factors. Here, we examined whether the repertoire of genes encoding killer immunoglobulin-like receptors (KIR) and genes for their ligands, C1/C2 and Bw4, may affect a susceptibility to NSCLC and response to treatment. We typed 269 NSCLC patients and 690 healthy control individuals for KIR genes and for their ligands. KIR genes were not associated with NSCLC. C1C2 genotype was less frequent whereas both C1C1 and C2C2 homozygotes were more frequent in patients than in controls (χ(2)=7.73; df=2; p=0.021). Patients positive for KIR2DL2 and KIR2DS2 gene and homozygous for the C1 ligand were 6 times more likely to respond to treatment than those with other genotypes (p=0.034). In accordance with this, patients with the KIR2DL2+/KIR2DS2+, C1C1 genotype survived longer than others (p=0.0094). Median survival was 23months for KIR2DL2/2DS2/C1C1-positive patients, but only 10 months for those with other genotypes.

Inhibitory and activatory KIR gene frequencies in the Polish population

Killer cell immunoglobulin‐like receptors (KIRs) present on natural killer cells and minor subpopulations of T cells recognize class I human leukocyte antigen (HLA) molecules on the surface of target cells. Human individuals differ by the presence or absence of some KIR genes on their chromosomes (haplotypic polymorphism). As KIRs (especially two‐immunoglobulin‐domain‐like containing, or KIR2D, molecules) are important for the outcome of tissue (particularly for haematopoietic stem cell) transplantation and possibly for pregnancy, the knowledge of KIR gene distribution in a given human population is of practical value. Therefore, we tested 175 healthy individuals from Poland for the presence or absence of these KIR genes which show haplotypic polymorphism and are expressed. Results were compared with those published for other human populations, showing close relations with other Caucasoids.

CTLA-4 gene polymorphisms and natural soluble CTLA-4 protein in psoriasis vulgaris.

CTLA‐4 molecule is an important inhibitor of T‐lymphocyte activation. Several single nucleotide polymorphisms (SNPs) in the CTLA‐4 gene were found, and their associations with many human diseases were described. So far, however, such studies have not been performed in psoriasis vulgaris in Caucasoids. Therefore, we examined the distribution of three CTLA‐4 SNPs: −1147C/T, −318C/T and +49 A/G in 116 patients with psoriasis vulgaris and 123 healthy blood donors using the polymerase chain reaction–restriction fragment length polymorphism method. For all three SNPs, the frequencies of alleles, genotypes and three‐point haplotypes were very similar in patients and controls, suggesting no contribution of these genetic variants to psoriasis.

Killer Immunoglobulin-like Receptor (KIR) and HLA Genotypes Affect the Outcome of Allogeneic Kidney Transplantation

Background Recipient NK cells may detect the lack of recipients (i.e., self) HLA antigens on donor renal tissue by means of their killer cell immunoglobulin-like receptors (KIRs). KIR genes are differently distributed in individuals, possibly contributing to differences in response to allogeneic graft. Methodology/Principal Findings We compared frequencies of 10 KIR genes by PCR-SSP in 93 kidney graft recipients rejecting allogeneic renal transplants with those in 190 recipients accepting grafts and 690 healthy control individuals. HLA matching results were drawn from medical records. We observed associations of both a full-length KIR2DS4 gene and its variant with 22-bp deletion with kidney graft rejection. This effect was modulated by the HLA-B,-DR matching, particularly in recipients who did not have glomerulonephritis but had both forms of KIR2DS4 gene. In contrast, in recipients with glomerulonephritis, HLA compatibility seemed to be much less important for graft rejection than the presence of KIR2DS4 gene. Simultaneous presence of both KIR2DS4 variants strongly increased the probability of rejection. Interestingly, KIR2DS5 seemed to protect the graft in the presence of KIR2DS4fl but in the absence of KIR2DS4del. Conclusions/Significance Our results suggest a protective role of KIR2DS5 in graft rejection and an association of KIR2DS4 with kidney rejection, particularly in recipients with glomerulonephritis.

6.7-kbp deletion in LILRA3 (ILT6) gene is associated with later onset of the multiple sclerosis in a Polish population

Recently published studies have implicated the deletion polymorphism in LILRA3 gene, as being associated with multiple sclerosis (MS). A total of 309 patients diagnosed with MS and 379 unrelated healthy volunteers were typed for 6.7-kbp deletion in LILRA3 gene. Simultaneously, presence or absence of HLA-DRB1(∗)1501 allele was established to assess the possibility of interaction between LILRA3 deletion and HLA-DRB1(∗)1501 status. In contrast to previous reports, we did not find any association of LILRA3 deletion with MS susceptibility. Also, the HLA-DRB1(∗)1501 stratification analysis showed no LILRA3 association with the disease. However, we observed that patients negative for the deletion may begin to suffer from MS significantly earlier than patients who are positive (p = 0.014). Similarly to the most European populations we found significantly higher frequency of HLA-DRB1(∗)1501 allele in cases than we found in controls (27.0% vs. 12.5%; p < 0.0001, OR = 2.6, 95%CI = 1.96-3.42).