Hereditary palmoplantar keratoderma - phenotypes and mutations in 64 patients.

BACKGROUND: Hereditary palmoplantar keratodermas (PPK) represent a heterogeneous group of rare skin disorders with epidermal hyperkeratosis of the palms and soles, with occasional additional manifestations in other tissues. Mutations in at least 69 genes have been implicated in PPK, but further novel candidate genes and mutations are still to be found. OBJECTIVES: To identify mutations underlying PPK in a cohort of 64 patients. METHODS: DNA of 48 patients was analysed on a custom-designed in-house panel for 35 PPK genes, and 16 patients were investigated by a diagnostic genetic laboratory either by whole-exome sequencing, gene panels or targeted single-gene sequencing. RESULTS: Of the 64 PPK patients, 32 had diffuse (50%), 19 focal (30%) and 13 punctate (20%) PPK. None had striate PPK. Pathogenic mutations in altogether five genes were identified in 31 of 64 (48%) patients, the majority (22/31) with diffuse PPK. Of them, 11 had a mutation in AQP5, five in SERPINB7, four in KRT9 and two in SLURP1. AAGAB mutations were found in nine punctate PPK patients. New mutations were identified in KRT9 and AAGAB. No pathogenic mutations were detected in focal PPK. Variants of uncertain significance (VUS) in PPK-associated and other genes were observed in 21 patients that might explain their PPK. No suggestive pathogenic variants were found for 12 patients. CONCLUSIONS: Diffuse PPK was the most common (50%) and striate PPK was not observed. We identified pathogenic mutations in 48% of our PPK patients, mainly in five genes: AQP5, AAGAB, KRT9, SERPINB7 and SLURP1.

Vascular component of hand-arm vibration syndrome: a 22-year follow-up study.

BACKGROUND: Vibration-induced white finger (VWF) is often assessed using the Stockholm Workshop Scale (SWS) and cold challenge plethysmography. However, long-term longitudinal studies using both methods are scarce. AIMS: To study the long-term course and prognostic factors of VWF assessed with the SWS and photoplethysmography (PPG), and to examine the effects of lifestyle on PPG score, regardless of VWF status. METHODS: Forty male construction workers were examined with a test battery and clinical examination in 1994 and 2016/17. RESULTS: At baseline, the sample comprised 27 workers with, and 13 without, symptoms of hand-arm vibration syndrome (HAVS). Thirty-five workers reported vibration exposure during follow-up. The mean age of the workers was 60 years (45-78) at follow-up. The paired t-test showed that PPG scores deteriorated from 1994 to 2017 in the 27 workers with HAVS in 1994 (mean difference 2.7 min, 95% confidence interval (CI) 0.2-5.2). However, there was no statistically significant change in SWS scores in these workers over time. Smoking and age were associated with PPG score deterioration. Vibration exposure during follow-up predicted SWS score deterioration: 1000 h of exposure predicted a deterioration stage of 0.09 (95% CI 0.03-0.16). Analysis of all 40 workers showed that 2017 PPG scores were associated with positive serum cotinine and self-reported smoking during follow-up. CONCLUSIONS: Whereas age and smoking predicted a PPG deterioration, continued vibration exposure predicted worsening of white finger symptoms. The association of PPG score and smoking should be considered in diagnostic and prognostic factor evaluations.

Genetics and pathogenesis of idiopathic scoliosis.

Idiopathic scoliosis (IS), the most common spinal deformity, affects otherwise healthy children and adolescents during growth. The aetiology is still unknown, although genetic factors are believed to be important. The present review corroborates the understanding of IS as a complex disease with a polygenic background. Presumably IS can be due to a spectrum of genetic risk variants, ranging from very rare or even private to very common. The most promising candidate genes are highlighted.

Single-cell transcriptome analysis of endometrial tissue.

STUDY QUESTION: How can we study the full transcriptome of endometrial stromal and epithelial cells at the single-cell level? SUMMARY ANSWER: By compiling and developing novel analytical tools for biopsy, tissue cryopreservation and disaggregation, single-cell sorting, library preparation, RNA sequencing (RNA-seq) and statistical data analysis. WHAT IS KNOWN ALREADY: Although single-cell transcriptome analyses from various biopsied tissues have been published recently, corresponding protocols for human endometrium have not been described. STUDY DESIGN, SIZE, DURATION: The frozen-thawed endometrial biopsies were fluorescence-activated cell sorted (FACS) to distinguish CD13-positive stromal and CD9-positive epithelial cells and single-cell transcriptome analysis performed from biopsied tissues without culturing the cells. We studied gene transcription, applying a modern and efficient RNA-seq protocol. In parallel, endometrial stromal cells were cultured and global expression profiles were compared with uncultured cells. PARTICIPANTS/MATERIALS, SETTING, METHODS: For method validation, we used two endometrial biopsies, one from mid-secretory phase (Day 21, LH+8) and another from late-secretory phase (Day 25). The samples underwent single-cell FACS sorting, single-cell RNA-seq library preparation and Illumina sequencing. MAIN RESULTS AND THE ROLE OF CHANCE: Here we present a complete pipeline for single-cell gene-expression studies, from clinical sampling to statistical data analysis. Tissue manipulation, starting from disaggregation and cell-type-specific labelling and ending with single-cell automated sorting, is managed within 90 min at low temperature to minimize changes in the gene expression profile. The single living stromal and epithelial cells were sorted using CD13- and CD9-specific antibodies, respectively. Of the 8622 detected genes, 2661 were more active in cultured stromal cells than in biopsy cells. In the comparison of biopsy versus cultured cells, 5603 commonly expressed genes were detected, with 241 significantly differentially expressed genes. Of these, 231 genes were up- and 10 down-regulated in cultured cells, respectively. In addition, we performed a gene ontology analysis of the differentially expressed genes and found that these genes are mainly related to cell cycle, translational processes and metabolism. LIMITATIONS, REASONS FOR CAUTION: Although CD9-positive single epithelial cells sorting was successfully established in our laboratory, the amount of transcriptome data per individual epithelial cell was low, complicating further analysis. This step most likely failed due to the high dose of RNases that are released by the cells' natural processes, or due to rapid turnaround time or the apoptotic conditions in freezing- or single-cell solutions. Since only the cells from the late-secretory phase were subject to more focused analysis, further studies including larger sample size from the different time-points of the natural menstrual cycle are needed. The methodology also needs further optimization to examine different cell types at high quality. WIDER IMPLICATIONS OF THE FINDINGS: The symbiosis between clinical biopsy and the sophisticated laboratory and bioinformatic protocols described here brings together clinical diagnostic needs and modern laboratory and bioinformatic solutions, enabling us to implement a precise analytical toolbox for studying the endometrial tissue even at the single-cell level.

Counteracting foaming caused by lipids or proteins in biogas reactors using rapeseed oil or oleic acid as antifoaming agents.

Foaming is one of the major operational problems in biogas plants, and dealing with foaming incidents is still based on empirical practices. Various types of antifoams are used arbitrarily to combat foaming in biogas plants, but without any scientific support this action can lead to serious deterioration of the methanogenic process. Many commercial antifoams are derivatives of fatty acids or oils. However, it is well known that lipids can induce foaming in manure based biogas plants. This study aimed to elucidate the effect of rapeseed oil and oleic acid on foam reduction and process performance in biogas reactors fed with protein or lipid rich substrates. The results showed that both antifoams efficiently suppressed foaming. Moreover rapeseed oil resulted in stimulation of the biogas production. Finally, it was reckoned that the chemical structure of lipids, and more specifically their carboxylic ends, is responsible for their foam promoting or foam counteracting behaviour. Thus, it was concluded that the fatty acids and oils could suppress foaming, while salt of fatty acids could generate foam.

Association study of FUT2 (rs601338) with celiac disease and inflammatory bowel disease in the Finnish population.

Homozygosity for a nonsense mutation in the fucosyltransferase 2 (FUT2) gene (rs601338G>A) leads to the absence of ABH blood groups (FUT2 non-secretor status) in body fluids. As the secretor status has been shown to be a major determinant for the gut microbial spectrum, assumed to be important in the gut immune homeostasis, we studied the association of rs601338-FUT2 with celiac disease (CelD) and inflammatory bowel disease (IBD) in the Finnish population. Rs601338 was genotyped in CelD (n = 909), dermatitis herpetiformis (DH) (n = 116), ulcerative colitis (UC) (n = 496) and Crohn's disease (CD) (n = 280) patients and healthy controls (n = 2738). CelD showed significant genotypic [P = 0.0074, odds ratio (OR): 1.28] and recessive (P = 0.015, OR: 1.28) association with the rs601338-AA genotype. This was also found in the combined CelD+DH dataset (genotype association: P = 0.0060, OR: 1.28; recessive association: P < 0.011, OR: 1.28). The A allele of rs601338 showed nominal association with dominant protection from UC (P = 0.044, OR: 0.82) and UC+CD (P = 0.035, OR: 0.84). The frequency of non-secretors (rs601338-GG) in controls, CelD, DH, UC and CD datasets was 14.7%, 18%, 18.1%, 14.3% and 16.1%, respectively. No association was evident in the DH or CD datasets alone. In conclusion, FUT2 non-secretor status is associated with CelD susceptibility and FUT2 secretor status may also play a role in IBD in the Finnish population.

Association of celiac disease genes with inflammatory bowel disease in Finnish and Swedish patients.

Some genetic loci may affect susceptibility to multiple immune system-related diseases. In the current study, we investigated whether the known susceptibility loci for celiac disease (CelD) also associate with Crohn's disease (CD) and/or ulcerative colitis (UC), the two main forms of inflammatory bowel disease (IBD), in Finnish patients. A total of 45 genetic markers were genotyped in a Finnish data set comprising 699 IBD patients and 2482 controls. Single-marker association with IBD and its subphenotypes was tested. A meta-analysis with a Swedish UC data set was also performed. A total of 12 single-nucleotide polymorphisms associated with CD and/or UC (P<0.05). In the subphenotype analysis, rs6974491-ELMO1 (P=0.0002, odds ratio (OR): 2.20) and rs2298428-UBE2L3 (P=5.44 × 10(-5), OR: 2.59) associated with pediatric UC and CD, respectively. In the meta-analysis, rs4819388-ICOSLG (P=0.00042, OR: 0.79) associated with UC. In the subphenotype meta-analysis, rs1738074-TAGAP (P=7.40 × 10(-5), OR: 0.61), rs6974491-ELMO1 (P=0.00052, OR: 1.73) and rs4819388-ICOSLG (P=0.00019, OR: 0.75) associated with familial UC, pediatric UC and sporadic UC, respectively. Multiple CelD risk loci also confer susceptibility for CD and/or UC in the Finnish and Swedish populations. Certain genetic risk variants may furthermore predispose an individual for developing a particular disease phenotype.

Genome-wide analysis of extended pedigrees confirms IL2-IL21 linkage and shows additional regions of interest potentially influencing coeliac disease risk.

Coeliac disease is a chronic inflammatory condition of the small intestine, triggered by dietary exposure to gluten in genetically susceptible individuals. Risk alleles at HLA-DQA1 and HLA-DQB1 are necessary for disease development, but are alone not sufficient for disease onset. We aimed to identify novel loci underlying susceptibility to coeliac disease through the use of extended Finnish and Hungarian families with multiple affected individuals. An initial whole-genome linkage approach yielded several loci that were followed up further using the Immunochip custom array. Loci with a parametric logarithm of odds (LOD) score of >1.3 were identified at 4q, 6p [human leukocyte antigen (HLA) region], 6q, 7p, 17p, 17q and at 22p. The 4q and 6q loci have been identified previously in coeliac disease risk, whereas follow-up analyses indicate that the 17p and 22p loci may be novel risk loci for coeliac disease. These loci harbour previously described risk variants for other autoimmune diseases, but their segregation patterns do not explain the linkage to coeliac disease. We followed up the linkage to the 4q region, containing the previously described interleukin (IL)2 and IL21 genes. The risk variants at 4q in the studied pedigrees are most likely distinct from previously described risk variants, indicating that the observed linkage may be due to rare high-risk variants of still unknown nature. The importance of this locus to coeliac disease risk was further shown by the finding that serum levels of IL21 were elevated in both untreated and treated coeliac patients compared to controls.

Influence of female hormonal factors, in relation to autoantibodies and genetic markers, on the development of rheumatoid arthritis in northern Sweden: a case-control study.

OBJECTIVES: To study the influence of female hormonal factors on the development of rheumatoid arthritis (RA) in relation to the human leucocyte antigen (HLA)-DRB1 shared epitope (SE), the protein tyrosine phosphatase (PTPN22) 1858T variant, anti-citrullinated protein antibodies (ACPAs), and immunoglobulin (Ig)M-rheumatoid factor (IgM-RF). METHODS: A case-control study (1:4) was nested within the Medical Biobank of northern Sweden. Females who had subsequently developed RA (n = 70), median of 2.7 years before the onset of symptoms, and matched controls (n = 280) were identified from among the blood donors. A questionnaire concerning previous exposures until disease onset, including hormonal and reproductive factors, and smoking habits was distributed. RESULTS: Breastfeeding was significantly associated with the development of RA [odds ratio (OR) 4.8, 95% confidence interval (CI) 1.43-15.8]. Increasing time of breastfeeding increased the risk of RA (OR 5.7, 95% CI 1.83-17.95) for breastfeeding ≥ 17 months. In a multiple logistic regression analysis, increasing time of breastfeeding (OR 9.5, 95% CI 2.14-42.43 for ≥ 17 months), seropositivity for ACPAs (OR 19.5, 95% CI 4.47-84.81), and carriage of the PTPN22 1858T variant (OR 3.2, 95% CI 1.36-7.54) remained significant predictors of RA. Users of oral contraceptives (OC) for ≥ 7 years had a decreased risk for development of RA (OR 0.37, 95% CI 0.15-0.93). CONCLUSIONS: A longer duration of breastfeeding increased the risk of developing RA, especially among individuals seropositive for ACPA or IgM-RF or carrying the PTPN22 1858T variant. Use of OC for ≥ 7 years was associated with a decreased risk.

Fine mapping of the CELIAC2 locus on chromosome 5q31-q33 in the Finnish and Hungarian populations.

Celiac disease is a chronic inflammation of the small intestine, arising in genetically predisposed individuals as a result of ingestion of dietary gluten. The only confirmed and functionally characterised genetic risk factors for celiac disease are the DQ2 or DQ8 heterodimers at the major histocompatibility complex (MHC) class II locus (CELIAC1). These genes are necessary but alone not sufficient for disease onset. Genome-wide linkage scans have suggested chromosome 5q31-q33 (CELIAC2) as an important risk locus for celiac disease. This region has also been associated to other inflammatory disorders, although as yet, no clear gene associations have been found. In the current study, 11 celiac disease candidate loci were screened for genetic linkage in the Hungarian population. As the CELIAC2 locus showed the strongest evidence for linkage, this locus was selected for follow-up. Seventeen candidate genes were selected from the CELIAC2 locus, and genotyped using 48 haplotype tagging single nucleotide polymorphisms (SNPs) in large Finnish and Hungarian family materials. A subset of these, 40 tagging SNPs in 15 genes, were genotyped in an independent set of Finnish and Hungarian cases and controls. We confirmed linkage of this region with celiac disease and report strong linkage in both the Finnish and Hungarian populations. The association analysis showed modest associations throughout the whole region. These association findings were not replicated in the case-control datasets. Our study strongly supports the role of the CELIAC2 locus in celiac disease, but it also highlights the need for a more powerful study design in the region, to locate the true disease risk variants.

Linkage and association study of FcgammaR polymorphisms in celiac disease.

The Fcgamma receptor cluster on chromosome 1q23 contains a number of genes that may affect susceptibility to celiac disease, but previous studies have yielded contradictory results. We studied the FcgammaRIIa*A519G (rs1801274) and FcgammaRIIIa*A559C (rs396991) single nucleotide polymorphisms in celiac disease families from Hungary and Finland and in celiac disease case-control materials from Hungary and Italy. Neither the Hungarian nor the Italian case-control material or a meta-analysis of the combined case-control material showed significant single-marker or haplotype association. In addition, neither linkage nor family-based association tests showed evidence for association in the Finnish or Hungarian family material. This study thus does not support a previous publication showing FcgammaR association with celiac disease.

The shared CTLA4-ICOS risk locus in celiac disease, IgA deficiency and common variable immunodeficiency.

IgA deficiency (IgAD) and common variable immunodeficiency (CVID) often co-occur in families, associating with chronic inflammatory diseases such as celiac disease (CD). ICOS (inducible co-stimulator) and CTLA4 (cytotoxic T-lymphocyte-associated protein-4) may be important in both disorders, as ICOS is necessary for Ig class-switching and CTLA4 negatively regulates T-cell activation. Linkage and association of CD with CTLA4-ICOS is well documented, we thus aimed to further pinpoint CD susceptibility by haplotype-tagging analysis. We genotyped 663 CD families from Finland and Hungary, 575 additional CD patients from Finland, Hungary and Italy; 275 Swedish and Finnish IgAD individuals and 87 CVID individuals for 14-18 genetic markers in CTLA4-ICOS. Association was found between CTLA4-ICOS and both IgAD (P=0.0015) and CVID (P=0.0064). We confirmed linkage of CTLA4-ICOS with CD (LOD 2.38, P=0.0005) and found association of CTLA4-ICOS with CD (P=0.0009). Meta-analysis of the IgAD, CVID and CD materials revealed intergenic association (P=0.0005). Disease-associated markers were associated with lower ICOS and higher CTLA4 expression, indicating that the risk haplotypes contain functional variants. In summary, we identified a novel shared risk locus for IgAD, CVID and CD, the first report of association between CTLA4-ICOS and IgAD. Association between CD and CTLA4-ICOS was also confirmed in a large European data set.

Myosin IXB gene region and gluten intolerance: linkage to coeliac disease and a putative dermatitis herpetiformis association.

BACKGROUND: Coeliac disease is caused by dietary gluten, which triggers chronic inflammation of the small intestine in genetically predisposed individuals. In one quarter of the patients the disease manifests in the skin as dermatitis herpetiformis. Recently, a novel candidate gene, myosin IXB on chromosome 19p13, was shown to be associated with coeliac disease in the Dutch and Spanish populations. The same gene has previously been associated with inflammatory bowel disease, systemic lupus erythematosus and rheumatoid arthritis risk, making myosin IXB a potential shared risk factor in these inflammatory disorders. METHODS: In this study, previously reported myosin IXB variants were tested for genetic linkage and association with coeliac disease in 495 Hungarian and Finnish families and in an additional 270 patients and controls. RESULTS AND CONCLUSION: The results show significant linkage (logarithm of odds (LOD) 3.76, p = 0.00002) to 19p13 which supports the presence of a genuine risk factor for coeliac disease in this locus. Myosin IXB variants were not associated with coeliac disease in this study; however, weak evidence of association with dermatitis herpetiformis was found. The association could not explain the strong linkage seen in both phenotypes, indicating that the role of other neighbouring genes in the region cannot be excluded. Therefore, more detailed genetic and functional studies are required to characterise the role of the myosin IXB gene in both coeliac disease and dermatitis herpetiformis.

Short term changes in lung function, leukocytosis in blood, and lachrymal fluid among bacterial single cell protein workers after an episode with high exposure to endotoxins.

AIMS: To study possible effects of endotoxin exposure among bacterial single cell protein workers on pulmonary function, blood parameters, and lachrymal fluid before and after a work shift. METHODS: The study included 23 men and five women who were examined at the start and at the end of a work shift. Most workers performed a task with unusually high exposure levels. Twelve of the workers were re-examined the day after. The workers were divided into three exposure groups: production workers with the highest assumed exposure levels (n = 18), engineers (n = 5), and clerks (n = 2). The median endotoxin level during a work shift was 34000 EU/m3 in the high exposure group (range 3300-89000 EU/m3 ), 11000 EU/m3 (range 350-27000 EU/m3) among the engineers, and 180 EU/m3 (range 60-300 EU/m3) for the clerks. The workers answered a questionnaire about work related symptoms. Assessment of lung function included dynamic lung volumes and flows. The blood analysis included cell count of leukocytes and mediators of inflammation, fibrinogen, interleukin-6 (IL-6), D-dimer, and C-reactive protein (CRP). Cells in lachrymal fluid were counted with a microscope. RESULTS: The forced vital capacity (FVC) changed significantly (p<0.05) from 5.34 l (SD 0.9) to 5.25 l (SD 0.9) and forced expired volume in one second (FEV1) from 4.15 l (SD 0.7) to 4.07 l (SD 0.7) during the work shift. The leukocytes increased significantly (p<0.05) from 6.9 10(9)/l (SD 1.2) to 7.7 10(9)/l (SD 1.5) and IL-6 from 1.5 ng/l (SD 0.6) to 3.31 ng/l (SD 2.7). Except for fibrinogen, which had a borderline increase and PEF that decreased, the parameters were normalised the day after. Four of the workers had an increase of neutrofile granulocytes in the lachrymal fluid during the shift. There was a significant association between the endotoxin concentration and decrease of FEV1 despite the use of powered respirators. CONCLUSIONS: During a work shift with unusual high levels of endotoxins at a plant manufacturing bacterial single cell protein the results show that FVC and FEV1 were reduced. Mediators of inflammation increased along with leucocytosis in blood and lachrymal fluid among the workers.

Growth of human lung adenocarcinoma in nude mice is influenced by various types of dietary fat and vitamin E.

Studies have shown effects of dietary lipids on carcinogenesis and tumour progression. Different mechanisms for the inhibitory effect of n-3 fatty acids (FA) have been proposed. The inhibition of the growth of subcutaneously transplanted A427 lung adenocarcinoma cells in athymic nude mice may occur due to an increased level of lipid peroxidation products and is the object of this study. The nude mice were fed diets supplemented with corn oil (CO), olive oil (OO) or K85, a mixture of ethyl esters of n-3 FAs, mainly eicosapentaenoic acid (EPA, 20:5, n-3) and docosahexaenoic acid (DHA, 22:6, n-3). Tumours of the n-3 FA group showed reduced growth. Peroxidation products measured by the thiobarbituric acid reactive substances (TBARS) test showed higher levels in tumours from n-3 FA fed mice than in the other diet groups. The growth inhibitory effects and the elevated level of TBARS in the n-3 FA diet group were counteracted by vitamin E supplement in the diet. Cu/Zn-superoxide dismutase (SOD) activity in liver did not differ greatly among the diet groups. The Ki-67 labelling index (LI), indicating cell proliferation rate was significantly lower in the K85 diet group compared to the other diet groups.

Fertility in mice after prenatal exposure to benzo[a]pyrene and inorganic lead.

Experimental evidence suggests that inorganic lead and benzo[a]pyrene (BaP) suppress the development of primordial oocytes during fetal life. We examined the single and combined effects of prenatal exposure to BaP and moderate doses of lead. The fertility and ovarian morphology of F1 female NMRI mice in four treatment groups (nine mice per group) were investigated: control; lead (F0 given 1 g PbCl2/L in drinking water until mating); BaP (10 mg/kg body weight daily by oral intubation on days 7-16 of F0 pregnancy); and combined lead and BaP. F1 groups exposed prenatally to BaP either alone or in combination with inorganic lead showed markedly reduced fertility with few ovarian follicles compared to controls, whereas the group exposed to lead only had measures comparable to the controls. Mice exposed to both lead and BaP had a significantly longer gestation period (days to litter) compared to mice exposed only to BaP, lead, or controls. There is a nonsignificant indication that the compounds together further reduce number of offspring, number of litters, and litter size. These results suggest that lead and BaP have synergistic effects on impairment of fertility. The possibility of synergism may be of human relevance as inorganic lead and BaP are ubiquitous environmental pollutants.

Effect modification by inorganic lead in the dominant lethal assay.

Experimental evidence suggests that inorganic lead may modify mutagenic events. We examined the modifying effect of lead on mutagenic events in late spermatogenesis in the dominant lethal assay. Twelve NMRI male mice were given lead chloride in the drinking water and 12 male mice received tap water without lead chloride. Cyclophosphamide (120 mg/kg b.w., i.p.) was given to six males in the lead treatment group and six males in the tap water group 1 week before mating. This resulted in four treatment groups: control, lead, cyclophosphamide, and lead plus cyclophosphamide. Cyclophosphamide given to the males (with or without lead treatment) reduced the numbers of live implants in mated females. The most prominent effect of cyclophosphamide was an increase of resorbed implants. Females mated to lead exposed male mice showed a nonsignificantly lower frequency of resorptions compared to controls. The results give no support to the hypothesis that inorganic lead may influence the mutagenicity of cyclophosphamide in the dominant lethal test.