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Biomedical subjects

S Koskimies

Publications and source records attributed to S Koskimies.

At least 91 records · Page 5Linked to original sources
PubMed1990

Autoantibodies and autoimmune diseases in young diabetics.

Another autoimmune disease was found to accompany insulin dependent diabetes mellitus (IDDM) in 14% of the young diabetics (n = 14) studied. Thyroid autoimmune disease was the most common of the accompanying autoimmune diseases, and was detected in 11% (n = 15) of the patients. Two thirds of the IDDM patients with autoimmune thyroiditis were hypothyroid, one was hyperthyroid, and 20% lacked detectable thyroid antibodies when thyroid disease was diagnosed. Coeliac disease was found in 2% of the patients, and one had Addison's disease. Autoantibodies were found in one third of the patients. Thyroid microsomal antibodies were detected in 22% of the patients, IgA anti-gliadin in 11%, gastric parietal cell antibodies in 3% and rheumatoid factor in 7%. Autoimmune disease and the relevant autoantibodies coexisted in 11% of the patients. Autoimmune disorders and autoantibodies were not associated to any particular HLA type. The distribution of the HLA-types in the patients was unusual in that the frequency of HLA-DR3 was not increased. The value of autoantibody tests in the diagnosis of functional disorders of the thyroid and of coeliac disease are discussed.

Adult↗
PubMed1990

Seronegative rheumatoid arthritis: a clinical study with HLA typing.

We examined both clinically and by determining HLA-A, -B, -C and -DR antigens 50 patients thought to have seronegative erosive polyarticular rheumatoid arthritis (RA) in Finland and the USSR. All the patients fulfilled at least 4 of the 1987 ARA criteria for RA. According to HLA typing and clinical findings, of which a part was collected by followup, the patients fell into 5 groups: HLA-B27 related diseases, putative psoriatic arthritis, putative juvenile chronic polyarthritis, and seropositive and seronegative RA. Our results indicate that most of the patients with seronegative RA had some other disease. In the remaining cases the presence of rheumatoid factors had not been examined adequately, especially at the early phase of disease. The classification of erosive seronegative polyarticular patients is discussed.

Adolescent↗
PubMed1989

Subacute cutaneous lupus erythematosus. Genetic markers and clinical and immunological findings in patients.

The role of HLA and complement genes was studied in 13 patients with subacute cutaneous lupus erythematosus. Genetic markers and by combining the major histocompatibility complex class I (HLA-A, -B, and -C), class II (HLA-DR), and class III (properdin factor B [BF] and C4) phenotyping with DNA level analysis of the C4 region. Of our patients, 54% had DR2 antigens and 50% had DR3 antigens, when the frequencies in the controls were 25% and 33%, respectively. The DR3 antigen was associated with annular skin lesions that were associated with a younger age at onset, whereas the DR2 antigen was associated with papulosquamous skin lesions and an older age at onset. The frequency of C4 null alleles was 83% in the patients and 50% in the controls. The null alleles were found in both C4A and C4B loci and were not associated with any special major histocompatibility complex haplotype. The DNA studies showed that the null phenotype mostly resulted from a gene deletion. A highly increased frequency of complement C4 null alleles may be a predisposing factor for cutaneous lupus erythematosus and especially of the subacute cutaneous type.

Adult↗
PubMed1989

Determination of deletion sizes in the MHC-linked complement C4 and steroid 21-hydroxylase genes by pulsed-field gel electrophoresis.

In man, the genes encoding the complement component C4 (C4A, C4B) of the immune system and the steroid 21-hydroxylase enzyme (CYP21A, CYP21B) of adrenal steroid biosynthesis are located in the major histocompatibility complex (MHC). Frequent gene deletions and duplications have been described in the C4 and CYP21 genes, particularly in patients with autoimmune diseases and congenital adrenal hyperplasia. Here we report the determination of deletion sizes in 11 chromosomes with six different deletions. The deletions spanned the C4A+CYP21A, C4B+CYP21A, and C4B+CYP21B gene pairs as determined by standard Southern blot analysis. The deletion size fell within the range of 30-38 kb in all the chromosomes, as determined by pulsed-field gel electrophoresis. Because the deletion sizes in most other gene clusters are more heterogeneous, the results suggest the involvement of a specific mechanism in the generation of C4+CYP21 deletions.

Chromosome Deletion↗
PubMed1989

Thyroid-infiltrating lymphocytes, thyroid function, and HLA-DR in juvenile autoimmune thyroiditis.

Eighteen patients with juvenile autoimmune thyroiditis were studied. At diagnosis 8 (44%) of the patients were euthyroid and 10 hypothyroid, whereas at the end of 6 to 12 months follow-up, 12 (66%) were euthyroid and 6 hypothyroid. All the patients were HLA-typed. The frequency of HLA-DR4 was increased in the patients when compared with the normal population, 63 vs 28% (p less than 0.01). An analysis of thyroid-infiltrating mononuclear cells revealed that the majority of the thyroid-infiltrating lymphocytes were T cells. More T lymphocytes and fewer B lymphocytes and HLA class II positive lymphocytes were found among the thyroid-infiltrating mononuclear cells in euthyroid than hypothyroid patients. The numbers of thyroid-infiltrating B lymphocytes correlated with the levels of thyroid microsomal antibodies. No correlation was found between thyroid function and thyroid antibodies.

Adolescent↗
PubMed1989

Immune responses to insulin in patients with insulin-dependent diabetes mellitus.

To examine the effect of the major histocompatibility locus (HLA) and the duration of insulin-dependent diabetes (IDDM) on immune responses to insulin we assayed insulin induced proliferation of blood mononuclear cells and measured insulin antibodies in 66 patients with newly diagnosed and in 56 patients with longstanding IDDM matched for the age at onset (less than or equal to 15 years). In up to two thirds of the patients blood mononuclear cells responded to insulins by proliferation, and insulin antibodies were found in two thirds of patients with IDDM of long duration. Insulin proliferation or antibodies were not associated to any particular HLA antigen. The frequency of HLA-DR3 in patients with newly diagnosed IDDM was not increased unlike in patients with IDDM of long duration. In addition, HLA-B8 was associated to HLA-DR3 nearly twice as often in patients with newly diagnosed IDDM as in patients with longstanding IDDM. Thus, patients with IDDM of recent onset and diagnosed within the last three years more frequently responded to insulin by proliferation and less often had HLA-DR3 than patients with IDDM of long duration and diagnosed about 20-25 years earlier.

Adult↗
PubMed1989

Major-histocompatibility-complex gene markers and restriction-fragment analysis of steroid 21-hydroxylase (CYP21) and complement C4 genes in classical congenital adrenal hyperplasia patients in a single population.

The gene CYP21B, encoding the steroid 21-hydroxylase enzyme of adrenal steroid biosynthesis, has been mapped to the human major histocompatibility complex (MHC). Deficiency of this enzyme leads to congenital adrenal hyperplasia (CAH). We report the phenotypes of the HLA and complement C4 and Bf genes, which are closely linked to the CYP21B gene, together with a detailed analysis of the CYP21 and C4 RFLP, in 17 Finnish families with CAH. The RFLP analysis with six restriction enzymes suggested that, altogether, 35% of the affected chromosomes had a CYP21B + C4B gene deletion, 9% an obvious gene conversion of the CYP21B gene to a CYP21A-like gene, and 3% a CYP21A + C4B duplication. The remaining 53% gave the RFLP patterns also found in nonaffected chromosomes. We also found that a 14.0-kb EcoRI RFLP marker of the CYP21 genes was strongly associated with the presence of a short C4B gene, suggesting that some of the RFLP markers found with the CYP21 probe may actually derive from C4B gene polymorphism. Three particular MHC haplotypes, each with a characteristic RFLP pattern, were found in many unrelated families. These three haplotypes accounted for 59% of the affected chromosomes in our study group, the rest (41%) of the affected chromosomes being distributed among various subtypes. The results suggest that, within a single, well-defined population such as in Finland, only a few CYP21B gene defects may constitute a substantial part of the affected chromosomes. This finding will help in genetic studies of CAH in such populations.

Adrenal Hyperplasia, Congenital↗
PubMed1988

Genetic susceptibility to multiple sclerosis. A co-twin study of a nationwide series.

The problems of differentiation between environmental and genetic influences on the development of multiple sclerosis are well known. Twin studies may provide valuable information on this question. However, most published twin series are selected and no through clinical twin studies based on epidemiologic series have been carried out. In this study, all available same-sex twin pairs with clinically definite multiple sclerosis derived from the Finnish Twin Cohort of 15815 pairs were studied by clinical evaluation, magnetic resonance imaging, and visual and auditory evoked responses. The mean length of follow-up of the pairs after the onset of symptoms of multiple sclerosis was 20 years. Two of the seven monozygotic pairs were concordant; one was definitely so, and in the other, the co-twin of the index case had, in addition to clinical findings, white matter changes suggestive of multiple sclerosis in magnetic resonance imaging and abnormal visual evoked responses. All six dizygotic pairs were discordant. The frequency of the HLA antigen DR2 in probands (69%) was significantly increased, but the distribution among the healthy subjects and patients showed nonsignificant differences. The results indicate a genetic influence on the susceptibility to multiple sclerosis, although still unknown genetic determinants are possible involved.

Adult↗
PubMed1988

DNA polymorphism unique for a complotype with deletion of HLA-linked C4B and 21-hydroxylase B genes causing congenital adrenal hyperplasia.

Defects in the enzyme steroid 21-hydroxylase (21-OH) result in congenital adrenal hyperplasia (CAH), a frequent disorder of steroid biosynthesis. The gene encoding the enzyme, 21-OHB, has been mapped adjacent to the complement component C4B gene in the human HLA gene complex. DNA-level analyses of patients with CAH have shown that the 21-OHB gene has often been deleted, but the detection of 21-OHB deletions in heterozygotes is often problematic because it is based on relative band intensities. We here report a DNA polymorphism in the C4A91 gene unique to one particular type of 21-OHB deletion occurring solely with a complement phenotype BfF C4A91 B null, shown earlier to be frequent in CAH patients. This marker makes direct detection of the 21-OHB deletion in heterozygotes possible.

Adrenal Hyperplasia, Congenital↗
PubMed1988

Transient IgA and IgM deficiencies are frequent in children with ulcerative colitis.

Serum immunoglobulin levels in 22 children with ulcerative colitis were followed for 2 years after diagnosis of the disease. A statistically significant depression of IgA, IgM, and IgG was noticed; depression of IgA and IgM was most frequent. The depression of immunoglobulin levels was transient and was most prominent during the first year of treatment. All patients in the study received sulphasalazine. Disease activity or steroid medication had no influence on immunoglobulin levels. The development of immunoglobulin deficiencies was not connected with any HLA antigen; we found decreased frequency of antigen B7 in the whole group.

Adolescent↗
PubMed1988

Low degree of DNA polymorphism in the HLA-linked lymphotoxin (tumour necrosis factor beta) gene.

Tumour necrosis factors (TNF) alpha (cachectin) and beta (lymphotoxin) are lymphokines with many biological activities. For example, the molecules regulate the immune system, which is of special interest since the genes for the TNF are located within the human major histocompatibility complex (MHC). The MHC encodes HLA-molecules that play a critical role in the cellular interactions of the immune response. To test whether genetic polymorphism in the TNF genes may be involved in the associations between HLA and autoimmune diseases, we here describe an analysis of DNA polymorphism in the human TNF-beta gene. The results show that the TNF-beta gene has only a low degree of DNA polymorphism, and that this is not associated with HLA antigens showing a strong association with autoimmune-like diseases.

Genetic Linkage↗
PubMed1988

Extended HLA haplotypes in families with insulin-dependent diabetes mellitus in northern Finland.

Haplotypes including HLA, Bf and C4 loci were analyzed in a material comprising 55 families with diabetic children. One hundred and ten haplotypes found in IDDM patients were compared with 101 haplotypes present only in healthy family members. Two complotypes, BfSC4A3B3 and SC4A0B1, were significantly more common (P less than 0.05) in the diabetic haplotypes, and these were in most cases found in haplotypic combinations with HLA-B15,Dw4,DR4 and HLA-B8,Dw3,DR3 genes, respectively. The B8/DR3 haplotype was better conserved, as 72% included the BfSC4A0B1 complotype as compared with only 35% of the B15/DR4 haplotypes with "high risk" C4A3B3 complement alleles (p less than 0.05). DR3 was found in 26% of the diabetic haplotypes and DR4 in 43%. DR4 associated with the Dw4 in 69% of cases and with Dw14 in 26% of the diabetic haplotypes. Our results confirm that the two phenotypes found earlier to be associated with IDDM in Northern Finland, e.g. "B15,BfS,C4A3B3,Dw4,DR4" and "B8,Bfs,C4A0B1,Dw3,DR3" are inherited as haplotypes.

Diabetes Mellitus, Type 1↗
PubMed1988

HLA antigens in IgA deficient paediatric patients.

HLA antigens (A, B, C and DR loci) were studied in 62 IgA-deficient (IgAd) paediatric patients: 17 with coeliac disease (CD), 13 with juvenile arthritis (JA), 27 with frequent respiratory tract infections (RTI) and five with other diseases. The frequencies of HLA antigens in IgAd patients were compared with those in healthy blood donors, and in CD and JA patients with normal serum IgA levels. The IgA deficiency in the patients showed significant associations with HLA A1, B8, B13, Cw6, DR3 and DR7 (P less than 0.0005, P corr less than 0.02 vs controls) and decreased frequencies of DR2 (P less than 0.0005, P corr less than 0.02 vs controls). The HLA associations typical of coeliac disease, increased frequencies of HLA-B8 and DR3, were evident among the IgAd coeliacs; in contrast to the coeliacs with normal IgA levels, the IgAd coeliacs showed a significant increase of the HLA-Cw6 allele (P less than 0.0005, P corr less than 0.02 vs control coeliacs). Increased frequencies of HLA-A1, B8, B13, Cw6, DR3 and DR7 were noted in the patients with RTI, which can be explained by the frequent occurrence of the haplotypes A1, B8, DR3 and B13, DR7, the latter haplotype often also having the Cw6 allele. Among the IgAd JA patients, the antigen frequencies were similar to those in the JA patients with normal serum immunoglobulins.

Adolescent↗
PubMed1988

Class-specific rheumatoid factors, DR antigens, and amyloidosis in patients with rheumatoid arthritis.

Class-specific rheumatoid factors (RFs) were measured by enzyme immunoassay in 59 patients with rheumatoid arthritis complicated by systemic amyloidosis (RA+A), 47 patients with rheumatoid arthritis without amyloid (RA), 106 patients with other rheumatic diseases (juvenile rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome), and 55 blood donors. The patients with RA+A were characterised by a high prevalence of RF negativity; the IgM RF concentration was raised in only 18 of the 59 patients (31%, p less than 0.001 v RA), the IgG RF concentration in 20 of 59 (34%, p less than 0.001 v RA), and the IgA RF concentration in 24 of 59 (41%, p less than 0.001 v RA). A higher prevalence of HLA-DR4 (p less than 0.001) and a lower prevalence of DR2 (p less than 0.05) were found among 48 tested patients with RA+A when compared with a control panel consisting of 500 blood donors. No significant differences in the prevalence of DR1-DR7 or B27 antigens were observed, however, between patients with RA with or without amyloid.

Amyloidosis↗