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Heikki Julkunen

Publications and source records attributed to Heikki Julkunen.

11 recordsLinked to original sources
PubMed2007

The human GIMAP5 gene has a common polyadenylation polymorphism increasing risk to systemic lupus erythematosus.

BACKGROUND: Several members of the GIMAP gene family have been suggested as being involved in different aspects of the immune system in different species. Recently, a mutation in the GIMAP5 gene was shown to cause lymphopenia in a rat model of autoimmune insulin-dependent diabetes. Thus it was hypothesised that genetic variation in GIMAP5 may be involved in susceptibility to other autoimmune disorders where lymphopenia is a key feature, such as systemic lupus erythematosus (SLE). MATERIAL AND METHODS: To investigate this, seven single nucleotide polymorphisms in GIMAP5 were analysed in five independent sets of family-based SLE collections, containing more than 2000 samples. RESULT: A significant increase in SLE risk associated with the most common GIMAP5 haplotype was found (OR 1.26, 95% CI 1.02 to 1.54, p = 0.0033). In families with probands diagnosed with trombocytopenia, the risk was increased (OR 2.11, 95% CI 1.09 to 4.09, p = 0.0153). The risk haplotype bears a polymorphic polyadenylation signal which alters the 3' part of GIMAP5 mRNA by producing an inefficient polyadenylation signal. This results in higher proportion of non-terminated mRNA for homozygous individuals (p<0.005), a mechanism shown to be causal in thalassaemias. To further assess the functional effect of the polymorphic polyadenylation signal in the risk haplotype, monocytes were treated with several cytokines affecting apoptosis. All the apoptotic cytokines induced GIMAP5 expression in two monocyte cell lines (1.5-6 times, p<0.0001 for all tests). CONCLUSION: Taken together, the data suggest the role of GIMAP5 in the pathogenesis of SLE.

Cytokines↗
PubMed2007

Prognosis of 5-year radiographic erosions of the wrist according to early, late, and persistent wrist swelling or tenderness in patients with early rheumatoid arthritis.

OBJECTIVE: To determine whether early inflammatory activity in the first year of disease compared to persistent or later occurrence of swelling or tenderness in the wrist joints is associated with 5-year erosions in the same joint in patients with early rheumatoid arthritis (RA). METHODS: A cohort of 195 patients with early active RA was enrolled in the Finnish RA Combination Trial. Swelling and tenderness of wrists were assessed at baseline and at 3, 6, 12, 24, 36, and 48 months. Radiographs of the wrists were taken at the baseline and at 5 years. The 237 wrist joints of 125 patients without erosions at baseline were classified according to wrist swelling, i.e., I: never swollen; II: swollen during first year only; III: swollen during the second to fourth year only; and IV: swollen during the first year and followup, and similarly according to tenderness. RESULTS: Thirty percent of the wrists were never swollen in all clinical examinations; 43% were swollen only during the first year; 11% were not swollen in the first year, but were swollen at some time during 24-48 months; and 16% of wrists were swollen during the first year and at some time during 24-48 months. At 5 years, 64% of 237 wrists remained free of erosions. Erosions developed in 82% of wrists that were swollen during both the first year and 24-48 months, versus 56% of wrists that were not swollen at first year but were swollen during 24-48 months, 31% of wrists that were swollen during the first year only, and 11% of wrists that were never swollen. Similar results were seen for joint tenderness. CONCLUSION: Wrist swelling during the first year only is associated with less future wrist radiographic damage than persistent swelling or swelling only during the followup. Our results emphasize the value of early and continuous suppression of inflammatory activity in early RA.

Adult↗
PubMed2005

Polymorphisms in the tyrosine kinase 2 and interferon regulatory factor 5 genes are associated with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease caused by both genetic and environmental factors. Genome scans in families with SLE point to multiple potential chromosomal regions that harbor SLE susceptibility genes, and association studies in different populations have suggested several susceptibility alleles for SLE. Increased production of type I interferon (IFN) and expression of IFN-inducible genes is commonly observed in SLE and may be pivotal in the molecular pathogenesis of the disease. We analyzed 44 single-nucleotide polymorphisms (SNPs) in 13 genes from the type I IFN pathway in 679 Swedish, Finnish, and Icelandic patients with SLE, in 798 unaffected family members, and in 438 unrelated control individuals for joint linkage and association with SLE. In two of the genes--the tyrosine kinase 2 (TYK2) and IFN regulatory factor 5 (IRF5) genes--we identified SNPs that displayed strong signals in joint analysis of linkage and association (unadjusted P<10(-7)) with SLE. TYK2 binds to the type I IFN receptor complex and IRF5 is a regulator of type I IFN gene expression. Thus, our results support a disease mechanism in SLE that involves key components of the type I IFN system.

Alleles↗
PubMed2005

Association analysis of the R620W polymorphism of protein tyrosine phosphatase PTPN22 in systemic lupus erythematosus families: increased T allele frequency in systemic lupus erythematosus patients with autoimmune thyroid disease.

OBJECTIVE: Recent case-control studies show associations of the minor T allele (of the C1858T single-nucleotide polymorphism corresponding to the R620W amino acid substitution) of PTPN22 with multiple autoimmune diseases, including systemic lupus erythematosus (SLE). We performed family-based association studies of this polymorphism in 4 independent cohorts containing SLE patients and their parents and/or other family members. METHODS: A total of 2,689 individuals from 902 independent Caucasian families with SLE were genotyped using polymerase chain reaction pyrosequencing (cohorts 1 and 2) and the Sequenom MassArray system (cohorts 3 and 4). The transmission disequilibrium test (TDT) and the pedigree disequilibrium test (PDT) were conducted to assess the evidence of association. RESULTS: The 1858 C > T allele frequencies of the parents showed no deviation from Hardy-Weinberg equilibrium within each cohort. No evidence of preferential transmission of the T allele from heterozygous parents to their affected offspring was observed in each of the 4 cohorts or in the combined sample. Consistent with the TDT result, the PDT analysis revealed no significant association between the T allele and SLE. In 54 of the 661 SLE patients (cohorts 1 and 3) with documented autoimmune thyroid disease, the T allele frequency was higher than in individuals with SLE alone (16.7% versus 8.5%; P = 0.008, odds ratio 2.16 [95% confidence interval 1.25-3.72]). CONCLUSION: The R620W polymorphism of the PTPN22 gene is not a major risk allele for SLE susceptibility in our sample of Caucasian individuals from northern America, the UK, or Finland, but it appears to be a risk factor for the concurrent autoimmune diseases of autoimmune thyroid disease and SLE.

Arginine↗
PubMed2004

Impact of initial aggressive drug treatment with a combination of disease-modifying antirheumatic drugs on the development of work disability in early rheumatoid arthritis: a five-year randomized followup trial.

OBJECTIVE: To compare the efficacy of therapy with a combination of disease-modifying antirheumatic drugs (DMARDs) versus therapy with a single DMARD in the prevention of work disability in patients with early rheumatoid arthritis (RA). METHODS: In the Finnish Rheumatoid Arthritis Combination Therapy trial, 195 patients with recent-onset RA were randomly assigned to receive either combination therapy with DMARDs (sulfasalazine, methotrexate, hydroxychloroquine) plus prednisolone or single therapy with a DMARD with or without prednisolone. After 2 years, the drug treatment strategy was no longer restricted. At baseline, 162 patients (80 in the combination-treatment group and 82 in the single-treatment group) were still working or at least available for work. After 5 years of followup, data on all sick leave and retirement were obtained from social insurance registers or case records. The main outcome for each patient was the cumulative duration of all sick leaves and RA-related disability pensions, divided by the observation period during which the patient was not retired because of another disease or because of age. RESULTS: The cumulative duration of work disability per patient-observation year was significantly lower in those randomized to combination therapy than in those randomized to single therapy: median 12.4 days (interquartile range [IQR] 0-54) versus 32.2 days (IQR 6-293) (P = 0.008, sex- and age-adjusted P = 0.009). This was mainly due to the difference in sick leaves (i.e., work disability periods </=300 days): median 11.7 days (IQR 0-44) per patient-observation year in those treated with combination therapy and 30.0 days (IQR 6-68) in those treated with single therapy (P = 0.002). No statistically significant difference was seen in RA-related disability pensions. CONCLUSION: Aggressive initial treatment of RA with a combination of DMARDs improves 5-year outcome in terms of lost productivity in patients with RA of recent onset.

Adult↗
PubMed2004

Haplotype associations define target regions for susceptibility loci in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by diverse and variable clinical manifestations. The etiology of SLE is still unknown, but both environmental and genetic factors are involved. Recent genome-wide scans and candidate genes studies in different ethnic groups have already suggested susceptibility loci for SLE, but most of the genetic component remains unexplained. We have previously conducted a genome-wide scan in 35 Finnish families multiply affected with SLE. With 417 microsatellite markers, we detected suggestive linkage in regions on chromosomes 6q and 14q as well as HLA on 6p. The 14q locus has also been implicated in three previous genome scans on SLE, whereas a partially overlapping region on 6q was implicated in one previous study. In an effort to obtain additional evidence for susceptibility loci on 6q and 14q and in order to refine their positions, we performed fine mapping at 1 cM density across the suggestive regions of linkage. Our results show evidence for excess sharing of a haplotype on 14q and excess transmission of a haplotype on 6q. Our results are compatible with the idea of a founder effect for susceptibility genes in SLE in central eastern Finland and suggest a path to the isolation of the putative susceptibility genes.

Chromosome Mapping↗
PubMed2004

Autoimmune response in mothers of children with congenital and postnatally diagnosed isolated heart block: a population based study.

OBJECTIVE: To study the autoimmune response in mothers of children with isolated congenital heart block (CHB) and heart block (HB) diagnosed postnatally. METHODS: We reviewed the Finnish hospital registries for patients born between 1950 and 2000 and diagnosed with isolated HB before the age of 16 years. Clinical data and sera for the determination of autoantibodies were available from 67 mothers of children with CHB and from 37 mothers of children with postnatally diagnosed HB 9.9 years and 22.6 years (mean) after the index delivery, respectively. Maternal antibodies to 52 kDa and 60 kDa SSA and 48 kDa SSB were determined by time-resolved fluoroimmunoassay (TR-FIA) and by immunoblotting. Other marker antibodies for connective tissue diseases (CTD) were determined by immunoblot and/or by immunofluorescence. The control group comprised 136 mothers with primary Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), or other CTD with healthy children. RESULTS: Sixty of our 67 mothers (90%) of children with CHB had antibodies to SSA or SSB by the methods initially used in this study. When retests and tests performed previously were taken into account, only 3 (4%) of the 67 mothers did not have any autoantibodies. Two (3%) of the 67 mothers had antibodies to dsDNA and one (1%) each to Jo-1/HRS, RNP-70 kDa, and histone proteins. Of 37 mothers of children with postnatally diagnosed HB, only 3 (8%) had any autoantibodies. Increased risk of having a child with CHB was indicated by maternal primary SS and high levels of anti-SSA and anti-SSB by all assays, whereas low risk was indicated by maternal SLE or other CTD and undetectable or low levels of the antibodies. No single anti-SSA or anti-SSB test was clearly superior to others, but in general, immunoblots were more specific than TR-FIA. CONCLUSION: Maternal autoimmune disorder is almost always associated with CHB but only rarely with postnatally diagnosed HB. Anti-SSA and anti-SSB are marker antibodies for mothers of children with CHB, and an increased risk of having an affected child is indicated by maternal primary SS and high titer antibodies to SSA and SSB.

Adult↗
PubMed2003

CCR3, CCR5, interleukin 4, and interferon-gamma expression on synovial and peripheral T cells and monocytes in patients with rheumatoid arthritis.

OBJECTIVE: To characterize cytokine and chemokine receptor profiles of T cells and monocytes in inflamed synovium and peripheral blood (PB) in patients with rheumatoid arthritis (RA) and other arthritides. METHODS: We studied PB and synovial fluid (SF) samples taken from 20 patients with RA and 9 patients with other arthritides. PB cells from 8 healthy adults were used as controls. CCR3, CCR5, and intracellular interferon-g (IFN-g) and interleukin 4 (IL-4) expression in CD8+ and CD8- T cell populations and in CD14+ cells were determined with flow cytometry. RESULTS: Expression of CCR5 and CCR3 by CD8-, CD8+ T cells and CD14+ monocytes was increased in SF compared to PB cells in patients with RA and other arthritides. The number of CD8+ T cells spontaneously expressing IL-4 and IFN-g was higher in SF than in PB in RA patients. Spontaneous CCR5 expression was associated with intracellular IFN-g expression in CD8+ T cells derived from SF in RA. In CD8- T cells the ratio of CCR5+/CCR3+ cells was increased in patients with RA compared to patients with other arthritides. The number of PB CD8- T cells expressing IFN-g after mitogen stimulation was higher in controls than in patients. In PB monocytes the ratio of CCR5+/CCR3+ cells was increased in patients with RA compared to patients with other arthritides and controls. CONCLUSION: T cells and monocytes infiltrating joints in RA and in other arthritides showed increased activation of both type 1 and type 2 immune markers. More pronounced type 1 immune response in joints, shown as an increased CCR5/CCR3 ratio, was found in the patients with RA versus those with other arthritides. Monocytes but not T cells in PB showed increased activation in RA.

Adult↗