POS0806 FINDINGS CONSISTENT WITH SUBCLINICAL VASCULITIS IN PATIENTS WITH NEW ONSET POLYMYALGIA: A SYSTEMATIC LITERATURE REVIEW AND A META-ANALYSIS OF COHORT DATA

Background:

GCA is characterized by cranial symptoms but imaging techniques show that patients with non-specific symptoms such as systemic inflammation or PMR may have undiagnosed large vessel (LV) GCA1. Although silent GCA in patients with clinically isolated PMR may have consequences for patients’ outcome, little is known about its prevalence and characteristics of affected patients.

Objectives:

To review data on the prevalence of silent GCA in newly diagnosed PMR patients without cranial GCA symptoms and to analyze which characteristics are associated with vascular involvement among PMR patients.

Methods:

We systematically screened PubMed, Embase and Web of Science databases and included studies screening for GCA in steroid naïve PMR patients without cranial symptoms consistent with GCA. Authors of the publications that used PET for vasculitis screening were invited to share their individual patient data (IPD) for a meta-analysis. We sought to define patient characteristics that were associated with vasculitis using univariable mixed effects logistic regression models with vascular involvement as the outcome, missing values were imputed using multilevel joint modeling multiple imputation. To fit a multivariable model with the candidate predictors we excluded variables that were hypothesized to have less medical relevance for the outcome and highly correlated inflammation markers (ESR, Lc).

Results:

Out of the 3047 studies screened independently by 2 authors (DG and TD), 13 fulfilled the inclusion criteria. These studies (published 1963-2019) reported on 543 PMR patients examined by temporal artery biopsy (n=175), ultrasound (n=110), PET or PET-CT (n=258). 115 PMR patients were diagnosed with GCA (21.2%), with prevalence ranging from 0-92%.

We collected IPD for 243 patients from 4 cohorts using PET and 3 using PET/CT for GCA diagnosis. The overall median age of patients was 72.3 years (IQR 66.4-78.0) and vasculitis was found in 65 patients (26.7%) (table 1).

Table 1.OverallPMRPMR+GCAn (%)243178 (73.3)65 (26.7)Female sex (%)146 (60.1)98 (55.1)48 (73.8)Shoulder girdle pain (%)236 (97.1)174 (97.8)62 (95.4)Pelvic girdle pain (%)174 (71.6)127 (71.3)47 (72.3)Inflammatory back pain (%)No107 (44.0)83 (46.6)24 (36.9)Yes106 (43.6)70 (39.3)36 (55.4)Lower limb pain (%)No87 (35.8)61 (34.3)26 (40.0)Yes81 (33.3)68 (38.2)13 (20.0)Weight loss (%)112 (46.1)78 (43.8)34 (52.3)CRP (mg/l) (median [IQR])46.0 [19.0, 77.7]44.0 [16.9, 74.2]52.0 [27.9, 85.0]ESR (mm/h) (mean (SD))65.2 (30.3)62.7 (30.2)72.3 (29.7)Hemoglobin (g/dl) (mean (SD))12.1 (1.5)12.2 (1.5)11.7 (1.6)Thrombocytes (1e+09/ml) (mean (SD))341.9 (106.3)323.9 (103.2)375.8 (104.6)

In the univariable analyses the following factors were most strongly associated with vasculitic PET findings: female sex (OR 2.31, CI 1.17-4.58), inflammatory back pain (OR 2.73, CI 1.32-5.64), temperature >37° (OR 1.83, CI 0.90-3.7), weight loss (OR 1.83, CI 0.96-3.51), thrombocytosis (i.e., patients with a thrombocyte count 1 SD above mean have an OR of 1.51, CI 1.05-2.18), anemia (i.e., 1 g/dl decrease in Hb below mean corresponds to an OR of 1.25, CI 1.00-1.56). Patients with lower limb pain were less likely to have vasculitis (OR 0.43, CI 0.19–0.95). The estimated ORs were very similar in the multivariable model although the 95%CIs became wider.

Conclusion:

Although the prevalence across published studies showed substantial variation, 6 out of 13 studies reported a prevalence of silent GCA in 18-40% of all PMR patients. The exploratory analysis of the collected IPD identified female sex, inflammatory back pain, fever, weight loss, absence of lower leg pain, thrombocytosis and anemia as factors associated with LV-GCA. These findings should be validated in future prospective cohort studies. The presence or absence of these factors may further aid in diagnosing LV-GCA in PMR patients.

References:

[1]Buttgereit F, Dejaco C, Matteson EL, Dasgupta B. Polymyalgia Rheumatica and Giant Cell Arteritis: A Systematic Review. JAMA. 2016 Jun 14;315(22):2442–58.

Acknowledgements:

The study is funded by the “Schweizerische Stiftung für die Erforschung der Muskelkrankheiten (SSEM)”.

Disclosure of Interests:

Daniele Silvio Gozzoli: None declared, Andrea Hemmig: None declared, Lars Hemkens: None declared, Laura Werlen: None declared, Hannah Ewald: None declared, Christoph Berger: None declared, Diego Kyburz Grant/research support from: DK reports personal fees from Abbvie, Gilead, Lilly, Novartis and Pfizer, outside of the submitted work, Stephan Imfeld: None declared, Markus Aschwanden: None declared, Mihaela Stegert: None declared, Dario Camellino: None declared, Marco Amedeo Cimmino: None declared, Corrado Campochiaro Grant/research support from: personal fees from Roche, Alessandro Tomelleri: None declared, Liesbet Henckaerts: None declared, Daniel Blockmans Speakers bureau: Paid speaker for Roche, Consultant of: Paid consultant for Roche, Patricia Moya: None declared, Hector Corominas: None declared, Russell Buchanan: None declared, Claire Owen Speakers bureau: CO has received speaking honoraria from Roche, Janssen, Novartis and Pfizer, and meeting sponsorship from Roche, UCB and Janssen, Yannick van Sleen: None declared, Elisabeth Brouwer Speakers bureau: E. Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017, 2018 which were paid to the UMCG, Consultant of: E. Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017, 2018 which were paid to the UMCG, Hiroyuki Ymashita: None declared, Thomas Daikeler: None declared

Systematic review and simulation study of ignoring clustered data in surgical trials

BACKGROUND

Multiple surgical procedures in a single patient are relatively common and lead to dependent (clustered) data. This dependency needs to be accounted for in study design and data analysis. A systematic review was performed to assess how clustered data were handled in inguinal hernia trials. The impact of ignoring clustered data was estimated using simulations.

METHODS

PubMed, Embase and the Cochrane Library were reviewed systematically for RCTs published between 2004 and 2013, including patients undergoing unilateral or bilateral inguinal hernia repair. Study characteristics determining the appropriateness of handling clustered data were extracted. Using simulations, various statistical methods accounting for clustered data were compared with an analysis ignoring clustering by assuming 100 hernias, with a varying percentage of patients having bilateral hernias.

RESULTS

Of the 50 eligible trials including patients with bilateral hernias, 20 (40 per cent) did not provide information on how they dealt with clustered data and 18 (36 per cent) avoided clustering by assessing the outcome by patient and not by hernia. None of the remaining 12 trials (24 per cent) considered clustering in the design or analysis. In the simulations, ignoring clustering led to an increased type I error rate of up to 12 per cent and to a loss in power of up to 15 per cent, depending on whether the patient or the hernia was the randomization unit.

CONCLUSION

Clustering was rarely considered in inguinal hernia trials. The simulations underline the importance of considering clustering as part of the statistical analysis to avoid false-positive and false-negative results, and hence inappropriate study conclusions.

Der Astigmatismus des Toroidkondensators

Auf der Grundlage der ionenoptischen Berechnungen von Herzog. Marschall. Hachenbe r g und Svartholm werden die Abbildungseigenschaften eines Toroid-Sektorkondensators angegeben. Die experimentelle Erprobung eines solchen Kondensators ergab hinlängliche Übereinstimmung mit der Rechnung.

Die Bildfehler des Toroidkondensators

Die radialen und axialen Bahngleichungen von Ionenstrahlen, die in der Nähe der Mittelbahn von Toroid-Sektorkondensatoren verlaufen, werden in zweiter Näherung berechnet. Es werden die Ergebnisse für die neun auftretenden radialen Bildfehler angegeben.

Experimentelle Untersuchungen der Rückstreuung von U235-Spaltteilchen an Goldschichten

U 235 fission products of known mass number ( = 135) and energy ( = 74.35 MeV) are scattered from polycristalline gold layers of about 1000 Å and 0.4 mm thickness at different angles of incidence (5°, 10°, 15° and 20° towards the surface) The reflected particles are traced by glass plates and Si surface barrier detectors. From the numbers, the positions and the diameters of the etched traces in the glass plates the percentages of the backscattering, the angular distributions, and the energies of the reflected particles are obtained

Parent-only interventions in the treatment of childhood obesity: a systematic review of randomized controlled trials

BACKGROUND

An effective and cost-effective treatment is required for the treatment of childhood obesity. Comparing parent-only interventions with interventions including the child may help determine this.

METHODS

A systematic review of published and ongoing studies until 2013, using electronic database and manual searches.

INCLUSION CRITERIA

randomized controlled trials, overweight/obese children aged 5-12 years, parent-only intervention compared with an intervention that included the child, 6 months or more follow-up. Outcomes included measures of overweight.

RESULTS

Ten papers from 6 completed studies, and 2 protocols for ongoing studies, were identified. Parent-only groups are either more effective than or similarly effective as child-only or parent-child interventions, in the change in degree of overweight. Most studies were at unclear risk of bias for randomization, allocation concealment and blinding of outcome assessors. Two trials were at high risk of bias for incomplete outcome data. Four studies showed higher dropout from parent-only interventions. One study examined programme costs and found parent-only interventions to be cheaper.

CONCLUSIONS

Parent-only interventions appear to be as effective as parent-child interventions in the treatment of childhood overweight/obesity, and may be less expensive. Reasons for higher attrition rates in parent-only interventions need further investigation.

A genome-wide linkage search for bipolar disorder susceptibility loci in a large and complex pedigree from the eastern part of Cuba

We present results from a genome-wide scan of a six generation pedigree with 28 affected members with apparently dominant bipolar I disorder from eastern Cuba. Genotypes were obtained using the early access version of the Genechip Mapping 10K Xba array from AFFYMETRIX. Parametric and non-parametric linkage analyses under dominant and recessive models were performed using GENEHUNTER v2.1r5. Two phenotypic models were included in the analyses: bipolar I disorder and recurrent depressive disorder, or bipolar I disorder only. LOD scores were calculated for the entire family combined, and for four subdivisions of the family. For the entire family a suggestive parametric LOD score was obtained under the dominant model and the broader phenotype at 14q11.2-12 (LOD = 2.05). In the same region, a non-parametric LOD score close to genome-wide significance was also obtained, based on the entire family (NPL = 7.31, P-value = 0.07). For two individual branches of the pedigree, genome-wide significance (P < 0.005) was obtained with NPL scores of 8.71 and 12.99, respectively, also in the same region on chromosome 14. Chromosome 5q21.3-22.3 also showed close to genome-wide significant linkage for the complete pedigree (NPL = 7.26, P = 0.07), also supported by significant linkage in one individual branch (NPL = 9.86, P < 0.005). In addition, genome-wide significant nonparametric results (P-values <0.005) were obtained for individual branches at 5p13.1-q12.3, 6p22.3, 8q13.3-21.13, and 10q22.3-23.32. Finally, 2p25.1-25.3, 2p13.3-14, 3p14.2, 6p22.3-24.1, 7p14.1-14.2, 8q12.2-12.3, 10q21.1-21.2, 14q13.1-21.1, 15q15.1-21.2, and 22q12.3-13.32 showed suggestive linkage in the complete family. Most of these potential susceptibility loci overlap with, or are close, to previous linkage findings. The locus on 5q may, however, represent a novel susceptibility locus.

A genome-wide search for alleles and haplotypes associated with autism and related pervasive developmental disorders on the Faroe Islands

The involvement of genetic factors in the etiology of autism has been clearly established. We undertook a genome-wide search for regions containing susceptibility genes for autism in 12 subjects with childhood autism and related pervasive developmental disorders (PDDs) and 44 controls from the relatively isolated population of the Faroe Islands. In total, 601 microsatellite markers distributed throughout the human genome with an average distance of 5.80 cM were genotyped, including 502 markers in the initial scan. The Faroese population structure and genetic relatedness of cases and controls were also evaluated. Based on a combined approach, including an assumption-free test as implemented in CLUMP, Fisher's exact test for specific alleles and haplotypes, and IBD(0) probability calculations, we found association between autism and microsatellite markers in regions on 2q, 3p, 6q, 15q, 16p, and 18q. The most significant finding was on 3p25.3 (P(T1)=0.00003 and P(T4)=0.00007), which was also supported by other genetic studies. Furthermore, no evidence of population substructure was found, and a higher degree of relatedness among cases could not be detected, decreasing the risk of inflated P-values. Our data suggest that markers in these regions are in linkage disequilibrium with genes involved in the etiology of autism, and we hypothesize susceptibility genes for autism and related PDDs to be localized within these regions.

Mutational screening and association study of glutamate decarboxylase 1 as a candidate susceptibility gene for bipolar affective disorder and schizophrenia

Recent evidence from postmortem studies suggests that GAD1 encoding the gamma-aminobutyric acid (GABA) synthetic enzyme GAD67 is a functional candidate susceptibility gene for both bipolar affective disorder (BPAD) and schizophrenia. Previous studies suggest linkage between D2S326 near GAD1 and BPAD. We systematically screened GAD1 exons, flanking intronic sequences, and the promoter sequence for polymorphisms in 16 BPAD patients and five controls from Denmark. We identified eight single nucleotide polymorphisms (SNPs) including two in the promoter sequence. An association study of SNPs covering GAD1 was performed in a Danish sample of 82 BPAD subjects and 120 controls and in a Scottish sample of 197 individuals with schizophrenia, 200 BPAD subjects and 199 controls. Linkage disequilibrium (LD) and haplotype frequencies were estimated from genotype data from eight SNPs. Strong pairwise LD was observed among all pairs of neighboring markers. In the Danish sample, we found weak association between BPAD and two promoter SNPs spaced 1 kb apart. Furthermore, one, two, and three loci haplotype analysis showed weak association with BPAD in the Danish sample. The results from the association studies indicate that promoter variants are of importance for the Danish BPAD cases and we cannot reject the hypothesis of GAD1 as a functional candidate gene for BPAD. No association was observed between BPAD or schizophrenia and any of the investigated SNPs in the Scottish sample set. Thus the results obtained from the Scottish sample suggest that the GAD1 gene variants do not play a major role in the predisposition to schizophrenia.

Joint multi-population analysis for genetic linkage of bipolar disorder or "wellness" to chromosome 4p

To test the hypothesis that the same genetic loci confer susceptibility to, or protection from, disease in different populations, and that a combined analysis would improve the map resolution of a common susceptibility locus, we analyzed data from three studies that had reported linkage to bipolar disorder in a small region on chromosome 4p. Data sets comprised phenotypic information and genetic marker data on Scottish, Danish, and USA extended pedigrees. Across the three data sets, 913 individuals appeared in the pedigrees, 462 were classified, either as unaffected (323) or affected (139) with unipolar or bipolar disorder. A consensus linkage map was created from 14 microsatellite markers in a 33 cM region. Phenotypic and genetic data were analyzed using a variance component (VC) and allele sharing method. All previously reported elevated test statistics in the region were confirmed with one or both analysis methods, indicating the presence of one or more susceptibility genes to bipolar disorder in the three populations in the studied chromosome segment. When the results from both the VC and allele sharing method were considered, there was strong evidence for a susceptibility locus in the data from Scotland, some evidence in the data from Denmark and relatively less evidence in the data from the USA. The test statistics from the Scottish data set dominated the test statistics from the other studies, and no improved map resolution for a putative genetic locus underlying susceptibility in all three studies was obtained. Studies reporting linkage to the same region require careful scrutiny and preferably joint or meta analysis on the same basis in order to ensure that the results are truly comparable.

A genome-wide search for risk genes using homozygosity mapping and microarrays with 1,494 single-nucleotide polymorphisms in 22 eastern Cuban families with bipolar disorder

Homozygosity mapping is a very powerful method for finding rare recessive disease genes in monogenic disorders and may also be useful for locating risk genes in complex disorders, late onset disorders where parents often are not available, and for rare phenotypic subgroups. In the present study, homozygosity mapping was applied to 24 persons with bipolar disorder from 22 inbred families. The families were selected irrespective of whether other affected family members were present or not. A genome wide screen using genotypes from only a single affected person in each family was performed using the AFFYMETRIX GeneChip HuSNP Mapping Assay, which contains 1,494 single nucleotide polymorphisms. At chromosome 17q24-q25 a parametric multipoint LOD score of 1.96 was found at WIAF-2407 and WIAF-2405. When analyzing 19 additional microsatellite markers on chromosome 17q the maximum parametric multipoint LOD score was 2.08, 1.5 cM proximal to D17S668. The present study replicates a recent significant linkage finding.

Possible evidence for a common risk locus for bipolar affective disorder and schizophrenia on chromosome 4p16 in patients from the Faroe Islands

Patients with schizophrenia (n=11) and bipolar affective disorder (n=17) from the relatively isolated population of the Faroe Islands were genotyped for 34 polymorphic markers on chromosome 4 in a search for allelic association and haplotype sharing among distantly related patients. When considering bipolar patients only, there was no clearcut support for any region on chromosome 4. The two-marker segment D4S394-D4S2983 at 4p16.1 was, however, supported by a P-value of 0.0162. For patients with schizophrenia, there was reasonable support for 4p16.1 as marker D4S2281 (P=0.0019), a two-marker segment (D4S2281-D4S1605, P=0.0009) and a three-marker segment (D4S2923-D4S2928-D4S1582, P-0.0005) appeared to be associated with schizophrenia, with some alleles/haplotypes occurring with different frequencies in patients compared to controls. When combining both psychiatric disorders, chromosome 4p16.1 received further support from five partially overlapping two- and three-marker segments (D4S394-D4S2983, P=0.0039; D4S2281-D4S1605, P=0.0027 and D4S394-D4S2983-D4S2923, P=0.006; D4S2923-D4S2928-D4S1582, P=0.00007; D4S1582-D4S1599-D4S2281, P=0.005). Increased haplotype sharing in patients with schizophrenia and in the combined data set was partly supported by Fisher's exact test and tests based on the genealogy. Our study yields support for a common risk gene for schizophrenia and bipolar affective disorder on the short arm of chromosome 4, as suggested by previous findings in the neighbouring Scottish population.

Individual and familial risk factors for bipolar affective disorders in Denmark

BACKGROUND

Few population-based studies have addressed risk factors for bipolar affective disorder.

OBJECTIVE

To study the possible association between bipolar affective disorder and history of mental illness in a parent or sibling; urbanicity of birth place; season of birth; sibship characteristics, including birth order; influenza epidemics during pregnancy; and early parental loss.

DESIGN

We used a population-based cohort of 2.1 million individuals based on data from the Danish Civil Registration System linked with the Danish Psychiatric Central Register.

SETTING

Nationwide population-based sample of all individuals hospitalized or in outpatient clinic contact for the first time with bipolar affective disorder. Patients Overall, 2299 individuals were first diagnosed with bipolar affective disorder during the 31.8 million person-years of follow-up.

RESULTS

Risk of bipolar affective disorder was associated with a history of bipolar affective disorder as well as other psychiatric disorders, including schizophrenia and schizoaffective disorder, in parents or siblings. People with a first-degree relative with bipolar affective disorder had a 13.63-fold (95% confidence interval, 11.81-15.71) increased risk of bipolar affective disorder. No other consistent associations were found with the exception of an association between early parental loss, in particular maternal, and bipolar affective disorder. Children who experienced maternal loss before their fifth birthday had a 4.05 (95% confidence interval, 1.68-9.77) increased risk of bipolar affective disorder.

CONCLUSIONS

Early parental loss may represent both environmental and genetic risk factors for bipolar affective disorder. Most of the risk factors included in our study that previously have been associated with schizophrenia were not associated with bipolar affective disorder, supporting that the 2 disorders may be at least partially separate etiological entities.

Head injury as a risk factor for bipolar affective disorder

BACKGROUND

Case reports have associated head injury with psychoses including affective disorders, but little is known regarding head injury as a risk factor for the onset of bipolar affective disorder.

METHODS

The Danish Psychiatric Case Register and the Danish National Patients Register were linked together with the Danish Population Register, thus identifying 10,242 patients with bipolar affective disorder, and 102,420 matched controls. History regarding head injury was recorded from the National Patients Register data. Data were analysed using conditional logistic regression.

RESULTS

Bipolar affective disorder was associated with an increased risk of a history of head injury (IRR=1.55; 95% CI 1.36-1.77). The increased risk was confined to head injury occurring less than 5 years before the first psychiatric admission. The finding could not be ascribed to increased accident proneness (as evaluated through the occurrence of other fractures not involving the skull).

LIMITATIONS

In studies based on clinical diagnoses only and limited to patients who were hospitalised for psychiatric disorder, exposure was limited to injuries leading to admission to hospital.

CONCLUSIONS

Head injury may be a contributing factor to the onset of bipolar affective illness. However, this factor is probably only relevant to a relatively small minority of cases.

Novel polymorphisms in the somatostatin receptor 5 (SSTR5) gene associated with bipolar affective disorder

The somatostatin receptor 5 (SSTR5) gene is a candidate gene for bipolar affective disorder (BPAD) as well as for other neuropsychiatric disorders. The gene is positioned on chromosome 16p13.3, a region that has been implicated by a few linkage studies to potentially harbor a disease susceptibility gene for BPAD. Recent evidence shows that the dopamine D2 receptor (DRD2) and SSTR5 interact physically to form heterodimers with enhanced functional activity. Brain D2 dopamine receptors are one of the major targets of neuroleptic treatments in psychiatric disorders. In this study we systematically screened the promoter and coding region of the SSTR5 gene for genetic variation that could contribute to the development of neuropsychiatric disorders. Eleven novel single nucleotide polymorphisms (SNPs) were identified including four missense SNPs, Leu48Met, Ala52Val, Pro109Ser and Pro335Leu. We carried out an association study of BPAD using 80 Danish cases and 144 control subjects, and replication analysis using 55 British cases and 88 control subjects. For the Danish population, association was suggested between silent SNP G573A and BPAD (P = 0.008). For the British population we found association to BPAD with missense mutation Leu48Met (P = 0.003) and missense mutation Pro335Leu (P = 0.004). The statistical significance of the association was, however, greatly reduced after correcting for multiple testing. When combining genotypes from Leu48Met and Pro335Leu into haplotypes, association to BPAD was found in the British population (P = 0.0007). This haplotype association was not replicated in the Danish population. Our results may indicate that the SSTR5 gene is involved in the etiology of BPAD or may exist in linkage disequilibrium with a susceptibility gene close to SSTR5. However, given the marginal statistical significance and the potential for false-positive results in association studies with candidate genes, further studies are needed to clarify this hypothesis.

A genome-wide scan shows significant linkage between bipolar disorder and chromosome 12q24.3 and suggestive linkage to chromosomes 1p22-21, 4p16, 6q14-22, 10q26 and 16p13.3

The present study reports a genomewide scan using linkage analysis for risk genes involved in bipolar disorder with 613 microsatellite markers including additional testing of promising regions. As previously published significant linkage was obtained at chromosome 12q24.3 with a two-point parametric lod score of 3.42 at D12S1639 including all members in both families (empirical P-value 0.00004, genome-wide P-value 0.0417). The multipoint parametric lod score at D12S1639 was 3.63 (genome-wide P-value 0.0265). At chromosome 1p22-p21 a parametric, affecteds-only two-point lod score of 2.75 at marker D1S216 was found (empirical P-value 0.0002, genome-wide P-value 0.1622). A three-point lod score of 2.98 (genome-wide P-value 0.1022) at D1S216, and a multipoint non-parametric analysis with a maximum NPL-all score of 17.60 (P-value 0.00079) at D1S216 further supported this finding. A number of additional loci on chromosomes 4p16, 6q14-q22, 10q26 and 16p13.3 yielded parametric lod scores around or above 2.

Possible parent-of-origin effect of Dopa decarboxylase in susceptibility to bipolar affective disorder

Dopa decarboxylase (DDC) catalyses the synthesis of both dopamine and serotonin as well as trace amines suggested to possess neuromodulating capabilities. We have previously reported evidence suggesting an association between DDC and bipolar affective disorder (BPAD) [Børglum et al., 1999]. To further investigate the possible role of DDC in BPAD, we analyzed a 1- and a 4-bp deletion variant-both of putative functional significance-in two new samples: a case-control sample with 140 cases and 204 controls, and 100 case-parents trios. We also tested for association in subjects with familial disease in both the new and the previously investigated samples. The previously reported association was not replicated in either of the new samples. However, a preponderance of the 1-bp deletion was increased by analysis of the familial cases separately for all case-control samples investigated, indicating a possible association with familial disease (combined analysis, P = 0.02). In the trio sample, a preferential paternal transmission of the 4-bp deletion was observed (P = 0.006). DDC is located next to the imprinted gene GRB10, which is expressed specifically from the paternal allele in fetal brains. Increased transmission of paternal DDC alleles has also been suggested in attention deficit hyperactivity disorder. We suggest that DDC might confer susceptibility to BPAD predominantly when paternally transmitted.

Is head injury a risk factor for schizophrenia?

BACKGROUND

The few studies that have examined whether head injury is a risk factor for later schizophrenia have had important methodological problems.

METHOD

We examined the rates of head injury among 8288 persons in the 15 years up to their first admission with schizophrenia and compared them with 82880 age- and gender-matched controls. We used hospitalization for concussion or severe head injury as a definition of head injury. We controlled for any generally altered accident proneness prior to schizophrenia by also comparing the groups with respect to exposition to fractures not involving the skull or spine.

RESULTS

Males with schizophrenia had significantly reduced exposure to concussion (OR = 0.864, p = 0.024), whereas females had significantly increased exposure (OR = 1.322, p = 0.025). No differences were found as regards severe head injury. Males had significantly reduced risk of other fractures (OR = 0.616, p < 0.0001), whereas the risk in females did not differ from controls (OR = 1.154, p = 0.189). After adjusting head injury with the risk for other fractures, both concussion and severe head injury were significantly increased in males (OR = 1.501, p < 0.001 and OR = 1.516. p < 0.001, respectively) but not in females (OR = 1.15, p = 0.413 and OR = 0.819, p = 0.442, respectively).

CONCLUSION

Our results do not exclude that for males, head injury may contribute to the risk for schizophrenia in a limited number of cases. This relation may also exist for females, but it is paralleled by an increased liability to traumas in general. Premorbid general accident proneness requires consideration when studying this association.

Search for common haplotypes on chromosome 22q in patients with schizophrenia or bipolar disorder from the Faroe Islands

Chromosome 22q may harbor risk genes for schizophrenia and bipolar affective disorder. This is evidenced through genetic mapping studies, investigations of cytogenetic abnormalities, and direct examination of candidate genes. Patients with schizophrenia and bipolar affective disorder from the Faroe Islands were typed for 35 evenly distributed polymorphic markers on 22q in a search for shared risk genes in the two disorders. No single marker was strongly associated with either disease, but five two-marker segments that cluster within two regions on the chromosome have haplotypes occurring with different frequencies in patients compared to controls. Two segments were of most interest when the results of the association tests were combined with the probabilities of identity by descent of single haplotypes. For bipolar patients, the strongest evidence for a candidate region harboring a risk gene was found at a segment of at least 1.1 cM including markers D22S1161 and D22S922 (P=0.0081 in the test for association). Our results also support the a priori evidence of a susceptibility gene to schizophrenia at a segment of at least 0.45 cM including markers D22S279 and D22S276 (P=0.0075). Patients were tested for the presence of a missense mutation in the WKL1 gene encoding a putative cation channel close to segment D22S1161--D22S922, which has been associated with schizophrenia. We did not find this mutation in schizophrenic or bipolar patients or the controls from the Faroe Islands.

Dopa decarboxylase genotypes may influence age at onset of schizophrenia

Several lines of evidence implicate dopa decarboxylase (DDC) with schizophrenia. By analysis of two putative functional DDC variants in 173 schizophrenic patients and 204 controls we tested the hypotheses that DDC is involved in: (1) predisposition to schizophrenia; and (2) modulation of age at disease onset. No association was observed with schizophrenia as a whole, whereas an association between DDC genotypes and age at disease onset was suggested in males (P = 0.03). This association was most pronounced in relation to genotypes of haplotypes comprising both variants, suggesting an additive model where one variant mediates early and the other late onset. Accordingly, the haplotype-based genotypes could be assigned into three groups by their possible relative effect on age at onset: an "early", "neutral" and "late" group. Dividing the male schizophrenics into four groups with increasing age at onset, the "early" genotypes were seen to decrease in frequency from 51.5% to 16.7% while the "late" genotypes increased from 12.1% to 33.3% (P = 0.02). The difference in mean age at onset between male patients with "early" genotypes vs patients with "late" genotypes was close to 5 years (95% CI: 0.7-8.8). Thus, DDC may possibly act as a modulator of age at onset in male schizophrenics.

An optical fibre sensor for in situ measurement of external species in fluids based on artificial neural network pattern recognition

An optical fibre sensor system capable of detecting contaminants (e.g. particles, inorganic or organic species) in water and other fluids is reported. In this article experimental results are presented for a single optical fibre sensor located at a distance of 150 m from the transmitter/receiver of the system. The fibre is addressed using an optical time domain reflectometer (OTDR) in order to achieve the spatial resolution (along the fibre length) necessary for this investigation. Novel signal processing techniques involving artificial neural networks and pattern recognition have been applied to the signals arising from the sensor in order to allow cross-sensitivity effects, e.g. from fouling due to calcification, to be extracted from the real measurand, e.g. alcohol content.

Further evidence for a bipolar risk gene on chromosome 12q24 suggested by investigation of haplotype sharing and allelic association in patients from the Faroe Islands

A number of studies have strongly suggested a susceptibility locus for bipolar affective disorder on chromosome 12q24. The present study investigates for a shared chromosomal segment among distantly related patients with bipolar affective disorder from the Faroe Islands, using 17 microsatellite markers covering 24 cM in the previously suggested region on chromosome 12q24. D12S342 showed possible allelic association to bipolar affective disorder (P-value using CLUMP below 0.01). Increased sharing among cases of two-marker haplotypes were suggested at D12S1614--D12S342 (P-values using CLUMP below 0.01), and D12S2075--D12S1675 (P-values using CLUMP around 0.001). The region of most interest is around 6 cM and bounded by markers D12S1614 and D12S1675 as suggested by the interesting two-marker haplotypes. This area contains the minimum interesting region between D12S342 and D12S1658 suggested by the previously reported haplotypes in the two Danish families with bipolar affective disorder.

The genetics of autism

OBJECTIVE

To review systematically the empirical evidence for the involvement of genetic risk factors in infantile autism.

METHOD

We aimed at including all relevant papers written in English. We conducted a Medline search in September 2000. In addition we searched the reference lists of related papers.

RESULTS

A relatively small number of reports including family and twin studies, comorbidity, cytogenetic and molecular genetic studies were reviewed.

CONCLUSION

As well family, twin, cytogenetic and molecular genetic studies supported the importance of genetic risk factors in infantile autism. In most individual cases probably at least a few gene variants simultaneously determine the genetic risk. Presently the most interesting chromosome regions concerning the aetiology of autism are chromosomes 7q31-35, 15q11-13 and 16p13.3 which have been suggested by different lines of genetic research.

The schizophrenic patient in the somatic hospital

OBJECTIVE

There is an increased risk in schizophrenia for premature death from illnesses in almost all organic systems. The present study analyses the Rate Ratio (RR) for schizophrenic patients' admissions to somatic departments in Denmark.

METHOD

20000 schizophrenic patients were identified in the Danish Psychiatric Central Register and 200000 sex- and age-matched controls were identified in the Danish Central Person Register. Both groups were searched for in the Danish National Patient Register in which admissions to all somatic departments are registered. Pulmonary and cardiovascular diseases are used as examples.

RESULTS

RR is increased for several diseases, especially infectious, up to a maximum of RR = 4.15 for severe heart failures and decreased to as low as RR = 0.35 for atherosclerotic diseases of the brain vessels.

CONCLUSION

It seems that individuals with schizophrenia are rarely treated for their physical illness in its early, less severe phases, but more likely in its acute phases when the disease is severe, life-threatening or painful.

Decreased risk of acute appendicitis in patients with schizophrenia or manic-depressive psychosis

The present study tests the hypothesis of a negative association between patients with schizophrenia, manic-depressive psychosis and acute appendicitis. Using the nation-wide Danish case registers the occurrence of acute appendicitis among up to 20,402 inpatients with schizophrenia and up to 10,281 inpatients with manic-depressive psychosis and ten individually matched control persons for each psychiatric patient was investigated. A case-control and follow-up design was applied. Persons who developed schizophrenia had a significantly decreased relative risk of acute appendicitis of 0.49 before and of 0.59 after first psychiatric admission. Similarly the occurrence of manic-depressive psychosis was associated with a decreased relative risk of acute appendicitis of 0.50 before and of 0.70 after first psychiatric admission. One or more unknown factors inversely affect the risk for the subsequent development of psychoses and acute appendicitis. Further studies of this relationship may help to clarify etiological or pathophysiological aspects of schizophrenia and manic-depressive psychosis.

Epidemiology in neurobiological research: exemplified by the influenza-schizophrenia theory

BACKGROUND

During recent years the strategy for aetiological research in schizophrenia has been to concentrate on two closely connected directions: the search for the genetic element and the search for environmental factors. Damage to the immature brain during pregnancy and delivery has given us the most interesting results from recent environmental research.

AIMS

To examine the validity of the influenza-schizophrenia hypothesis.

METHOD

A review of register-based epidemiological studies in Denmark conducted over a 10-year period.

RESULTS

The studies reviewed provided strong inferential evidence in favour of the hypothesis, but some methodological problems are unresolved and not all replication studies have been positive.

CONCLUSIONS

The brain-damage hypothesis points to possibilities for identifying high-risk individuals at an early stage of life and perhaps establishing specific preventive programmes. There is, however, a great need for closer international collaboration in future research.

No evidence of increased risk for schizophrenia or bipolar affective disorder in persons with aneuploidies of the sex chromosomes

BACKGROUND

Several case reports and reviews have suggested an increased incidence of schizophrenia or bipolar disorder among persons with sex chromosome aneuploidies, but this observation may have been caused by biased sampling.

METHODS

The 1122 individuals with sex chromosome aneuploidies registered in the Danish Cytogenetic Central Register were screened in the Danish Psychiatric Central Register for admissions with schizophrenia or bipolar affective disorder. Both registers are population based and have existed since 1968 and 1969 respectively. Relative risks were calculated for schizophrenia, bipolar affective disorder and either schizophrenia or bipolar disorder combined as one phenotype. Since hospitalization for a psychiatric disorder increases the probability that a cytogenetic examination is performed, the relative risks could be inflated, and they were therefore adjusted accordingly.

RESULTS

Aneuploidies of the X or Y chromosomes were not associated with an increased risk of schizophrenia or bipolar disorder. The occurrence of the combined phenotype including both schizophrenia and bipolar disorder was significantly reduced among persons with Turner's syndrome and significantly increased among individuals with the 47, XYY karyotype.

CONCLUSIONS

This population-based study did not find evidence supporting the presence of risk alleles for schizophrenia or bipolar disorder on the X chromosome or the pseudoautosomal region on the Y chromosome. The findings of an increased risk for the combined phenotype to XYY males and the reduced risk for persons with Turner's syndrome are interesting but difficult to explain with present neurobiological knowledge and inconsistent with the other findings of the study.

A population-based register study of the association between schizophrenia and rheumatoid arthritis

The authors investigated the association between schizophrenia and rheumatoid arthritis. The design is a population-based case-control and follow-up study. The cases were 20495 patients admitted for schizophrenia and registered in the Danish Psychiatric Case Register. A total of 204912 persons matched on age and gender and chosen from the general population served as controls. Admissions for rheumatoid arthritis and other non-autoimmune, musculoskeletal disorders were checked in the Danish National Patient Register. Odds ratios and relative risks were estimated by the Mantel-Haenszel estimator and Poisson regression. The same analyses were carried out for 10242 patients with bipolar affective disorder and 102420 controls for comparison. Individuals with schizophrenia had a reduced risk for being admitted with rheumatoid arthritis [odds ratio 0.44 (CI 0.24-0.81)] in the case-control study. A similar result was found in the follow-up study, but the incidence of the degenerative disorders in the musculoskeletal system was equally significantly lower in both studies. The incidence of rheumatoid arthritis among the bipolar patients was the same as in the control population. The negative association between schizophrenia and rheumatoid arthritis may thus be the result of ascertainment bias and selection due to under reporting and treatment of the medical illness. Clinicians are reminded of the difficulties in detecting medical illness among individuals with schizophrenia.

Two novel variants in the DOPA decarboxylase gene: association with bipolar affective disorder

DOPA decarboxylase (DDC), also known as aromatic L-amino acid decarboxylase (AADC), is an enzyme involved in the synthesis of the important neurotransmitters dopamine, norepinephrine, and serotonin. In addition, it participates in the synthesis of trace amines; compounds suggested to act as endogenous modulators of central neurotransmission. Thus, DDC is regarded as a potential susceptibility gene for a variety of neuropsychiatric disorders. The aim of the present study was to examine the role of DDC in bipolar affective disorder (BPAD). By screening 10 individuals for sequence variations in the coding region of the DDC gene as well as in the neuron-specific promoter and 5' untranslated regions we were able to identify two fairly frequent variants: a 1-bp deletion in the promoter and a 4-bp deletion in the untranslated exon 1. Both deletions affect putative binding sites for known transcription factors, suggesting a possible functional impact at the level of expression. The two variants were applied in an association study including 80 Danish bipolar patients, 112 English bipolar patients, 223 Danish controls, and 349 English controls. Analyzing the combined material, a significant association was found between the 1-bp deletion and BPAD with P-values of 0.037 (allelic) and 0.021 (genotypic). The frequency of the 1-bp deletion was 13.3% in patients and 9.4% in controls with a corresponding odds ratio of 1. 48 (95% CI: 1.02-2.15). The results presented suggest that DDC may act as a minor susceptibility gene for bipolar affective disorder.

Mapping studies on a pericentric inversion (18) (p11.31 q21.1) in a family with both schizophrenia and learning disability

Chromosomal abnormalities that co-occur with psychiatric disorders can be useful direct pointers to the locus of susceptibility genes. Two families with pericentric inversions of chromosome 18, inv 18(p11.3 q21.1) and psychiatric illness have previously been described. We have fine mapped the chromosomal breakpoints of the rearrangement in a clinically well, inversion carrier from one of these families where other inversion carriers suffered from chronic schizophrenia or severe learning disability. Yeast artificial chromosomes (YACs) from the Whitehead/MIT physical maps of human chromosome 18 have been positioned relative to the chromosomal breakpoints and a number of YACs that span these breakpoints have been identified. Linkage and association studies have previously suggested these regions of chromosome 18q and 18p as candidate loci harbouring genes involved in bipolar disorder and schizophrenia.

Screening for somatization and hypochondriasis in primary care and neurological in-patients: a seven-item scale for hypochondriasis and somatization

The aim of this study was to investigate the internal and external validity of the Whiteley Index as a screening instrument for somatization illness. A 14-item version of the Whiteley Index for hypochondriacal traits was given to 99 of 191 consecutive primary care patients, aged 18-65 years, and to 100 consecutive patients, aged 18-60 years, admitted for the first time to a neurological ward. The primary care sample was, in addition, interviewed by means of the SCAN (Schedules for Clinical Assessment in Neuropsychiatry) psychiatric interview. The GPs and the neurologists were asked to rate various characteristics of the patients that might indicate somatization. The internal validity of the Whiteley Index was tested by means of latent structure analysis. On this basis, a reduced seven-item scale (Whiteley-7 scale) and two subscales (i.e., an Illness Conviction and Illness Worrying scale, each with three items) were constructed. All three had a high internal validity fitting into the very restricted Rasch statistical model (p>0.05) and an acceptable transferability between most of the subpopulations investigated. In the primary care population, the Whiteley-7 and the Illness Conviction scales at cut-point 0/1 showed 1.00 and 0.87 sensitivity and 0.65 and 0.87 specificity, respectively, using as "gold standard" the fulfillment of criteria for at least one ICD-10 somatoform disorder, and 0.71 and 0.63 sensitivity and 0.62 and 0.87 specificity, respectively, as gold standard for the fulfillment of criteria for at least one DSM-IV somatoform disorder, excluding the NOS diagnostic group. The Illness Worrying subscale showed less impressive performance in this respect. The agreement between the Whiteley-7 scale including the two subscales and neurologists' rating and the GPs' rating and the somatization subscale on the SCL-90 was modest or worse. It may be concluded that the Whiteley-7 scale and the Illness Conviction subscale had acceptable psychometric profiles, and both seem to be promising screening tools for not only hypochondriasis but also for somatoform disorders in general.

A haplotype-based study of lithium responding patients with bipolar affective disorder on the Faroe Islands

The Faroe Islands are a small group of islands in the North Atlantic Ocean, situated between Norway, Iceland and Scotland. The origin of the population is thought to be a mixture of Norwegian, Danish and British. The islands were populated at the same time as Iceland, i.e. around 1100 years ago, and the size of the population was around, and occasionally below, 4000 inhabitants until 1800, after which it increased to its present-day level of around 45,000. The population is descended from Scandinavian and British ancestors. Because of the low number of founders and small size for many centuries, the Faroese population is perhaps the most valuable European population for genetic mapping of complex disease genes. The present study searched for haplotype sharing on chromosome 18 among eight lithium responding patients with bipolar affective disorder related, on average, 6.2 generations ago, using 30 DNA markers. In order to obtain as homogeneous a sample as possible, strict inclusion criteria based on severity of phenotype, geography and treatment response, were applied. Evidence suggestive of increased haplotype sharing on the distal part of chromosome 18q23 in the region implicated by Freimer and co-workers was found. However, methods of genetic analysis which might provide a conclusive result are not yet available.

Infantile autism and associated autosomal chromosome abnormalities: a register-based study and a literature survey

Infantile autism is a heterogenous disorder with unknown aetiology. Evidence from the relatively few family and twin studies suggests a genetic component. Co-occurrence or cosegregation between infantile autism and chromosomal abnormalities may identify candidate regions, which could be tested in linkage or association studies. The purpose of this study was to use the Danish Cytogenetic Central Register in order to detect autosomal chromosome abnormalities associated with infantile autism, and to review the literature for cases of autism associated with autosomal chromosome abnormalities to identify candidate chromosomal regions. The register-based study identified possible candidate regions on chromosome 7q21 and 10q21.2, which have not previously been reported. A few interesting candidate regions, 15q11-13, 16q23, and 17p11.2 were found in the literature survey.

Effects of family history and place and season of birth on the risk of schizophrenia

BACKGROUND

Although a family history of schizophrenia is the best-established risk factor for schizophrenia, environmental factors such as the place and season of birth may also be important.

METHODS

Using data from the Civil Registration System in Denmark, we established a population-based cohort of 1.75 million persons whose mothers were Danish women born between 1935 and 1978. We linked this cohort to the Danish Psychiatric Central Register and identified 2669 cases of schizophrenia among cohort members and additional cases among their parents.

RESULTS

The respective relative risks of schizophrenia for persons with a mother, father, or sibling who had schizophrenia were 9.31 (95 percent confidence interval, 7.24 to 11.96), 7.20 (95 percent confidence interval, 5.10 to 10.16), and 6.99 (95 percent confidence interval, 5.38 to 9.09), as compared with persons with no affected parents or siblings. The risk of schizophrenia was associated with the degree of urbanization of the place of birth (relative risk for the capital vs. rural areas, 2.40; 95 percent confidence interval, 2.13 to 2.70). The risk was also significantly associated with the season of birth; it was highest for births in February and March and lowest for births in August and September. The population attributable risk was 5.5 percent for a history of schizophrenia in a parent or sibling, 34.6 percent for urban place of birth, and 10.5 percent for the season of birth.

CONCLUSIONS

Although a history of schizophrenia in a parent or sibling is associated with the highest relative risk of having the disease, the place and season of birth account for many more cases on a population basis.

Significant linkage between bipolar affective disorder and chromosome 12q24

Chromosome 12q23-q24.1 has been implied by a few linkage and association studies as a candidate region for affective disorder. The present study investigated for linkage between bipolar affective disorder and 16 microsatellite markers covering chromosome 12q22-q24 in two Danish families. Assuming homogeneity and a dominant mode of inheritance, a significant two-point lod score of 3.37 was found at D12S1639, when only bipolar patients were considered as affected. The lod score was supported by neighbouring markers. The empirical P-value for this lod score was 0.00002. Non-parametric analyses using SimIBD supported this finding, with P-values of 0.00003 and 0.005 at D12S1639. An overlapping segment of chromosome 12q24 was shared among all except one of the bipolar patients, with apparently different haplotypes in each family.

Support for the possible locus on chromosome 4p16 for bipolar affective disorder

Significant evidence for linkage between bipolar affective disorder and markers on chromosome 4p16 has been reported in Scottish families. Linkage analyses using 16 DNA markers covering more than 50 cM from chromosome 4pter-4p12, including candidate genes encoding the dopamine D5 receptor and an adrenergic receptor (2C), were performed in two Danish families with bipolar affective disorder. Assuming homogeneity in the two families, the highest lod score found in the two-point linkage analyses was 2.00 at 0.03 recombination fraction for D4S394, i.e. the marker which also was most significant in the original Scottish study. Simulation showed that such a lod score would only occur six out of 10,000 times with an unlinked marker. Though the present study thus replicates the Scottish findings according to the criteria suggested by Lander and Kruglyak, caution is warranted as the mode of inheritance which yielded the highest lod score in the two studies was different. Final proof of a disease locus in the Scottish and our study has to await the identification of a DNA sequence of functional significance for bipolar disorder.

A functional variant of the serotonin transporter gene in families with bipolar affective disorder

BACKGROUND

The serotonin transporter protein (SERT) reuptakes serotonin from synapses and has been implied as the site of therapeutic action of many antidepressant drugs. SERT is one of the most relevant candidate genes for bipolar affective disorder. Recently a functionally important 44 basepair deletion in the regulatory region of the SERT gene was described. Association between this variant and affective disorder has been suggested.

METHODS

The present study analysed this variation and another variation in the SERT gene and nearby DNA markers in order to test for linkage between SERT and bipolar affective disorder in two Danish families.

RESULTS AND CONCLUSION

There was no evidence that variants in the SERT gene were a stronger dominant disease gene for the development of affective disorder in the families. The possibility of a recessive disease gene at or near SERT could not be excluded.

LIMITATIONS

The present study cannot exclude if variations at or near the SERT gene were weak susceptibility genes or determine if they are important for other characteristics than presence or absence of disease.

CLINICAL RELEVANCE

Further studies of the SERT gene in affective and other disorders, as well as in relation to treatment response to antidepressants are needed.