Etiologic heterogeneity among non-Hodgkin lymphoma subtypes: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Non-Hodgkin lymphoma (NHL) comprises biologically and clinically heterogeneous subtypes. Previously, study size has limited the ability to compare and contrast the risk factor profiles among these heterogeneous subtypes.

METHODS

We pooled individual-level data from 17 471 NHL cases and 23 096 controls in 20 case-control studies from the International Lymphoma Epidemiology Consortium (InterLymph). We estimated the associations, measured as odds ratios, between each of 11 NHL subtypes and self-reported medical history, family history of hematologic malignancy, lifestyle factors, and occupation. We then assessed the heterogeneity of associations by evaluating the variability (Q value) of the estimated odds ratios for a given exposure among subtypes. Finally, we organized the subtypes into a hierarchical tree to identify groups that had similar risk factor profiles. Statistical significance of tree partitions was estimated by permutation-based P values (P NODE).

RESULTS

Risks differed statistically significantly among NHL subtypes for medical history factors (autoimmune diseases, hepatitis C virus seropositivity, eczema, and blood transfusion), family history of leukemia and multiple myeloma, alcohol consumption, cigarette smoking, and certain occupations, whereas generally homogeneous risks among subtypes were observed for family history of NHL, recreational sun exposure, hay fever, allergy, and socioeconomic status. Overall, the greatest difference in risk factors occurred between T-cell and B-cell lymphomas (P NODE < 1.0×10(-4)), with increased risks generally restricted to T-cell lymphomas for eczema, T-cell-activating autoimmune diseases, family history of multiple myeloma, and occupation as a painter. We further observed substantial heterogeneity among B-cell lymphomas (P NODE < 1.0×10(-4)). Increased risks for B-cell-activating autoimmune disease and hepatitis C virus seropositivity and decreased risks for alcohol consumption and occupation as a teacher generally were restricted to marginal zone lymphoma, Burkitt/Burkitt-like lymphoma/leukemia, diffuse large B-cell lymphoma, and/or lymphoplasmacytic lymphoma/Waldenström macroglobulinemia.

CONCLUSIONS

Using a novel approach to investigate etiologic heterogeneity among NHL subtypes, we identified risk factors that were common among subtypes as well as risk factors that appeared to be distinct among individual or a few subtypes, suggesting both subtype-specific and shared underlying mechanisms. Further research is needed to test putative mechanisms, investigate other risk factors (eg, other infections, environmental exposures, and diet), and evaluate potential joint effects with genetic susceptibility.

A multiplex PCR procedure for polymorphic analysis of GSTM1 and GSTT1 genes in population studies

A deletion polymorphism in glutathione S-transferase theta (GSTT1) gene was recently discovered in humans. Similar to the GSTM1 gene, GSTT1 is also recognized as a risk modifier in exposed populations. To evaluate the role of genetic polymorphism in health effects, the combined genetic polymorphism of different genes should be taken into consideration. In the present study, we have developed a multiplex PCR approach for simultaneous replication of both genes for molecular analysis. The multiplex PCR protocol was validated using donor DNA with different polymorphic combinations for both genes from two different ethnic populations (North Americans and Egyptians). The prevalence of the GSTM1 null genotype was 51% among North Americans and 44% among Egyptians. The prevalence of the GSTT1 null genotype was 15% among North Americans and 14.7% among Egyptians. Combined polymorphism analysis of both genes revealed that 6.3% of North Americans harbor the deleted genotype of both genes compared to 8.8% of the Egyptians. The data indicate that there is no major difference in allelic distribution of both genes between the ethnic populations. The multiplex PCR assay used in this study has the advantage of reducing the time, effort and cost required to carry out such analysis. It will also significantly enhance the ability to use genetic screening techniques as a potential tool for early detection of health outcomes in exposed populations.

Historical analysis of participation in 161 km ultramarathons in North America

Participation trends in 100 m (161 km) ultramarathon running competitions in North America were examined from race results from 1977 through 2008. A total of 32, 352 finishes accounted for by 9815 unique individuals were identified. The annual number of races and number of finishes increased exponentially over the study period. This growth in number of finishes occurred through a combination of (1) an increase in participation among runners >40 years of age from less than 40% of the finishes prior to the mid-1980s to 65-70% of the finishes since 1996, (2) a growth (p < 0.0001) in participation among women from virtually none in the late 1970s to nearly 20% since 2004, and (3) an increase in the average annual number of races completed by each individual to 1.3. While there has been considerable growth in participation, the 161 km ultramarathon continues to attract a relatively small number of participants compared with running races of shorter distances.

Diabetes in American Indians and other native populations of the New World

This is a review of previous and more recent observations on the prevalence and manifestations of diabetes in aboriginal populations of the New World. Rates of diabetes have now been measured or estimated in more than eighty of these groups in the Americas, Greenland, Polynesia, Micronesia and Melanesia. Diabetes was probably uncommon in all these native populations prior to 1940. It is now rife in many of these groups, but still rare in many. Among certain of these populations, rates of diabetes in adults still differ more than tenfold. Among groups of diabetics there are probably significant intertribal differences in the susceptibility to certain manifestations and complications such as retinopathy and coronary disease. There appear to be peculiarities in the insulin secretion patterns of certain of these tribes.

The available evidence does not rule out the possibility that genetic factors play an important role in determining inter-tribal differences in prevalence and manifestations. But it is also clear that environmental factors exert powerful effects. Low rates of diabetes have been observed in Athapascan tribes and in some Shoshonean tribes. Diabetes was also rare prior to 1940 in Athapascan and Shoshonean Indians of Oklahoma. But diabetes has recently become common in these Oklahoma tribes. They were formerly lean and are now fat. The status of the many Oklahoma tribes is of particular interest because they represent seven of the eight major linguistic groups of North American Indians, having originated in very diverse parts of the Continent. Rates are now high in all Oklahoma tribes for which evidence is adequate to permit an estimate of prevalence. This includes fifteen tribes drawn from seven different linguistic groups. In seven additional Oklahoma tribes preliminary evidence, although less complete, suggests the probability that rates are also high.

Studies of the dramatic emergence of diabetes and its manifestations in these aboriginal groups has considerable potential for gaining a better understanding of the genetic and environmental factors which influence risk and pathophysiology of diabetes and its complications.

Cancer risks in first-generation immigrants to Sweden

We used the nationwide Swedish Family-Cancer Database to analyse cancer risks in 613,000 adult immigrants to Sweden. All the immigrants had become parents in Sweden and their median age at immigration was 24 years for men and 22 years for women. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for 18 cancer sites using native Swedes as a reference. Data were also available from compatriot marriages. All cancer was decreased by 5% and 8% for immigrant men and women, respectively. However, most of the male increase was due to lung cancer for which male immigrants showed a 41% excess. Among individual cancer sites and immigrant countries, 110 comparisons were significant, 62 showing protection and 48 an increased risk. Most of the differences between the rates in immigrants and Swedes could be ascribed to the variation of cancer incidence in the indigenous populations. Some high immigrant SIRs were 5.05 (n = 6, 95% CI 1.82-11.06) for stomach cancer in Rumanian women and 2.41 (41, 1.73-3.27) for lung cancer in Dutch men. At some sites, such as testis, prostate, skin (melanoma), kidney, cervix and nervous system, the SIRs for immigrants were decreased; in some groups of immigrants SIRs were about 0.20. The highest rates for testicular cancer were noted for Danes and Chileans. Women from Yugoslavia and Turkey had an excess of thyroid tumours. All immigrant groups showed breast, endometrial and ovarian cancers at or below the Swedish level but the differences were no more than 2-fold.

Incidence and severity of gestational diabetes mellitus according to country of birth in women living in Australia

Gestational diabetes mellitus (GDM) was diagnosed in 1928 of 35,253 (5.5%) tested pregnancies at the Mercy Maternity Hospital in Melbourne between 1979 and the end of 1988. Compared with women born in Australia and New Zealand, the incidence of GDM was significantly greater in women born on the Indian subcontinent (15%); in women born in Africa (9.4%), Vietnam (7.3%), Mediterranean countries (7.3%), and Egypt and Arabic countries (7.2%); and in Chinese (13.9%) and other Asian (10.9%) women. There was no significant difference for women born in the United Kingdom and northern Europe (5.2%), Oceania (5.7%), North America (4.0%), or South America (2.2%). With the World Health Organization criteria as a guide to the severity of hyperglycemia, compared with mothers born in Australia and New Zealand, there were significant increases in the incidences of the more severe grades of GDM in parturients born in the Mediterranean region, Asia, the Indian subcontinent, Egypt, and Arabic countries. The incidence of GDM increased significantly in all racial groups, rising from 3.3% during 1979-1983 to 7.5% during 1984-1988.

Autoantibodies to fibrillarin in systemic sclerosis (scleroderma). An immunogenetic, serologic, and clinical analysis

OBJECTIVE

To determine the frequency, clinical associations, and any major histocompatibility complex correlations of antifibrillarin antibodies in patients with systemic sclerosis (SSc).

METHODS

Antifibrillarin antibodies were determined by indirect immunofluorescence, immunoblotting, and immunoprecipitation, and HLA class II alleles by DNA oligotyping, in a large cohort of SSc patients.

RESULTS

Antifibrillarin was found in 8% of 335 SSc sera and was significantly more common in blacks (16%) than whites (5%), in males (33%) than females (14%), and in patients with cardiac, renal, or gut involvement. The HLA class II haplotype DRB1*1302, DQB1*0604 was found significantly more frequently in SSc patients with antifibrillarin compared with race-matched normal controls and 260 SSc patients without antifibrillarin. In addition, 1 or more of the HLA-DQB1 alleles *0604, *0301, *0602, and/or *0302 was found in all antifibrillarin-positive patients, and 62% of the antifibrillarin-positive patients had 2 of these HLA-DQB1 alleles, a highly significant difference from both race-matched normal controls and antifibrillarin-negative SSc patients.

CONCLUSION

Antifibrillarin, although an infrequent nucleolar autoantibody, is a marker for severe SSc, especially in blacks and males, and is strongly associated with a unique HLA haplotype, as well as with combinations of certain HLA-DQB1 alleles.

Loiasis in endemic and nonendemic populations: immunologically mediated differences in clinical presentation

To define the clinical spectrum of loiasis more precisely and to begin to assess the immunologic basis for the difference in clinical manifestations between visitors to endemic areas and natives of these areas, 51 West African patients with loiasis were evaluated and compared with 42 infected expatriates. Microfilaremia was present in 90% and Calabar swellings in only 16% of the endemic patients. Conversely, only 10% of the expatriates were microfilaremic while 95% complained of Calabar swellings. The endemic population showed significantly decreased levels of peripheral blood eosinophils, parasite-specific IgG, and lymphocyte proliferation to parasite antigens compared with the nonendemic population. These findings support the hypothesis that differences in the modulation of the immune response to parasite antigen are responsible for the observed differences in clinical presentation between expatriate and endemic populations with loiasis.

Cancer risks in second-generation immigrants to Sweden

We used the nationwide Swedish Family-Cancer Database to analyze cancer risks in Sweden-born descendants of immigrants from European and North American countries. Our study included close to 600,000 0-66-year-old descendants of an immigrant father or mother. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for 17 cancer sites using native Swedes as a reference. All cancer was marginally below the Swedish incidence in offspring of immigrant origin. Decreased SIRs were observed for breast cancer among Norwegian descendants, melanoma among descendants of Hungarian fathers and ovarian and bladder cancer among descendents of Finnish mothers, all consistent with the difference in cancer incidence between Swedes and the indigenous populations. Cervical cancer was increased in daughters of Danish men, whereas thyroid cancer and non-Hodgkin's lymphoma were in excess in offspring of parents of Yugoslav and Asian descent. Even these results agreed with the high incidence rates in parents compared to Swedes, except that for non-Hodgkin's lymphoma other explanations are needed; these may be related to immune malfunction. Comparison of the results between the first- and the second-generation immigrants suggest that the first 2 decades of life are important in setting the pattern for cancer development in subsequent life. Birth in Sweden sets the Swedish pattern for cancer incidence, irrespective of the nationality of descent, while entering Sweden in the 20s is already too late to influence the environmentally imprinted program for the cancer destiny.

Limited sequence variation in human T-lymphotropic virus type 1 isolates from North American and African patients

Nucleotide sequences were determined from the env genes of three HTLV-I clones derived from two North American patients and one African patient with adult T-cell leukemia/lymphoma (ATLL). In addition, sequences from the pX region, between env and the 3'LTR, were determined from one of these isolates. These data were compared to sequences derived from HTLV-I isolates of two Japanese ATLL patients, a Japanese patient with HTLV-I-associated myelopathy or tropical spastic paraparesis (HAM/TSP) and a Caribbean ATLL patient. Nucleotide sequence variation was found to be less than 6% in coding and noncoding regions. Predicted amino acid sequences varied between 0.6 and 1.8% in the envelope, 0-3.7% in rex, 0.8-2.5% in the tax gene product, and 3-14.0% in the pX-I open reading frame. Comparisons of the predicted amino acid sequences of the surface envelope protein (SU-gp46) suggest that the variation between isolates of different geographical origins is greater than that between isolates obtained from the same region of the world.

Virologic and genetic studies relate Amerind origins to the indigenous people of the Mongolia/Manchuria/southeastern Siberia region

A commonly held theory is that the first wave of migrants into the New World was derivative from the ethnic groups then inhibiting eastern Siberia. However, these ethnic groups lack a mtDNA haplogroup (B) that is well represented in Amerindian tribes. Also, the time depth of the other three mtDNA haplogroups found in Amerindians (A, C, and D) appears to be greater in the Amerindians than in the eastern Siberian ethnic groups. In this communication we demonstrate that the human T-cell lymphotrophic virus type II, present in 11 of the 38 Amerindian tribes thus far examined, is not present in any of the 10 ethnic groups of eastern Siberia that we have studied. However, the virus has just been reported in the indigenous population of Mongolia, and mtDNA haplogroup B is also represented in this region. On the basis of these facts, we propose that the ancestors of the first migrants to the New World were not derived from north and central Siberia but from populations to the south, inhabiting the regions of Mongolia, Manchuria, and/or the extreme southeastern tip of Siberia.

Medical history, lifestyle, family history, and occupational risk factors for chronic lymphocytic leukemia/small lymphocytic lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are two subtypes of non-Hodgkin lymphoma. A number of studies have evaluated associations between risk factors and CLL/SLL risk. However, these associations remain inconsistent or lacked confirmation. This may be due, in part, to the inadequate sample size of CLL/SLL cases.

METHODS

We performed a pooled analysis of 2440 CLL/SLL cases and 15186 controls from 13 case-control studies from Europe, North America, and Australia. We evaluated associations of medical history, family history, lifestyle, and occupational risk factors with CLL/SLL risk. Multivariate logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We confirmed prior inverse associations with any atopic condition and recreational sun exposure. We also confirmed prior elevated associations with usual adult height, hepatitis C virus seropositivity, living or working on a farm, and family history of any hematological malignancy. Novel associations were identified with hairdresser occupation (OR = 1.77, 95% CI = 1.05 to 2.98) and blood transfusion history (OR = 0.79, 95% CI = 0.66 to 0.94). We also found smoking to have modest protective effect (OR = 0.9, 95% CI = 0.81 to 0.99). All exposures showed evidence of independent effects.

CONCLUSIONS

We have identified or confirmed several independent risk factors for CLL/SLL supporting a role for genetics (through family history), immune function (through allergy and sun), infection (through hepatitis C virus), and height, and other pathways of immune response. Given that CLL/SLL has more than 30 susceptibility loci identified to date, studies evaluating the interaction among genetic and nongenetic factors are warranted.

The potato's contribution to population and urbanization: evidence from a historical experiment

We exploit regional variation in suitability for cultivating potatoes, together with time variation arising from their introduction to the Old World from the Americas, to estimate the impact of potatoes on Old World population and urbanization. Our results show that the introduction of the potato was responsible for a significant portion of the increase in population and urbanization observed during the eighteenth and nineteenth centuries. According to our most conservative estimates, the introduction of the potato accounts for approximately one-quarter of the growth in Old World population and urbanization between 1700 and 1900. Additional evidence from within-country comparisons of city populations and adult heights also confirms the cross-country findings.

Medical history, lifestyle, family history, and occupational risk factors for follicular lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Follicular lymphoma (FL) has been linked with cigarette smoking and, inconsistently, with other risk factors.

METHODS

We assessed associations of medical, hormonal, family history, lifestyle, and occupational factors with FL risk in 3530 cases and 22639 controls from 19 case-control studies in the InterLymph consortium. Age-, race/ethnicity-, sex- and study-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression.

RESULTS

Most risk factors that were evaluated showed no association, except for a few modest or sex-specific relationships. FL risk was increased in persons: with a first-degree relative with non-Hodgkin lymphoma (OR = 1.99; 95% CI = 1.55 to 2.54); with greater body mass index as a young adult (OR = 1.15; 95% CI = 1.04 to 1.27 per 5 kg/m(2) increase); who worked as spray painters (OR = 2.66; 95% CI = 1.36 to 5.24); and among women with Sjögren syndrome (OR = 3.37; 95% CI = 1.23 to 9.19). Lower FL risks were observed in persons: with asthma, hay fever, and food allergy (ORs = 0.79-0.85); blood transfusions (OR = 0.78; 95% CI = 0.68 to 0.89); high recreational sun exposure (OR = 0.74; 95% CI = 0.65 to 0.86, fourth vs first quartile); who worked as bakers or millers (OR = 0.51; 95% CI = 0.28 to 0.93) or university/higher education teachers (OR = 0.58; 95% CI = 0.41 to 0.83). Elevated risks specific to women included current and longer duration of cigarette use, whereas reduced risks included current alcohol use, hay fever, and food allergies. Other factors, including other autoimmune diseases, eczema, hepatitis C virus seropositivity, hormonal drugs, hair dye use, sun exposure, and farming, were not associated with FL risk.

CONCLUSIONS

The few relationships observed provide clues suggesting a multifactorial etiology of FL but are limited in the extent to which they explain FL occurrence.

Mutation analyses of North American APS-1 patients

Autoimmune polyendocrinopathy syndrome type 1 (APS-1; MIM# 240300) is a rare autosomal recessively inherited disease characterised by destructive autoimmune diseases of endocrine glands. The gene responsible for APS-1, known as AIRE (for autoimmune regulator), was recently identified and contains motifs suggestive of a transcription regulator. To date, nine APS-1-associated mutations have been identified in the AIRE gene, including two common mutations R257X and 1094-1106del. In addition to these two mutations, we report seven novel mutations in 16 APS-1 patients from North America. We found that 1094-1106del and R257X were the most common mutations in this population of mixed geoethnic origin, accounting for 17/32 and 4/32 alleles, respectively. Haplotype analyses suggest that both are recurrent mutations, occurring on several different haplotypes with closely linked markers. All the novel mutations appear to be rare, occurring in only single APS-1 families. After examining all coding sequences and exon/intron boundaries of the AIRE gene, the other APS-1 allele remained unidentified in three patients. Genotype-phenotype correlations for APS-1 remain difficult, suggesting that other genetic or environmental factors, or both, influence the clinical presentation and disease progression in individual APS-1 patients.

Non-random association between alleles detected at D4S95 and D4S98 and the Huntington's disease gene

Analysis of many families with linked DNA markers has provided support for the Huntington's disease (HD) gene being close to the telomere on the short arm of chromosome 4. However, analysis of recombination events in particular families has provided conflicting results about the precise location of the HD gene relative to these closely linked DNA markers. Here we report an investigation of linkage disequilibrium between six DNA markers and the HD gene in 75 separate families of varied ancestry. We show significant non-random association between alleles detected at D4S95 and D4S98 and the mutant gene. These data suggest that it may be possible to construct high and low risk haplotypes, which may be helpful in DNA analysis and genetic counselling for HD, and represent independent evidence that the gene for HD is centromeric to more distally located DNA markers such as D4S90. This information may be helpful in defining a strategy to clone the gene for HD based on its location in the human genome.

Screening for Lrrk2 G2019S and clinical comparison of Tunisian and North American Caucasian Parkinson's disease families

Mutations in the leucine-rich repeat kinase-2 gene (LRRK2) are responsible for some forms of familial as well as sporadic Parkinson's disease (PD). The purpose of this study was to examine the frequency of a single pathogenic mutation (6055G > A) in the kinase domain of this gene in United States and Tunisian familial PD and to compare clinical characteristics between patients with and without the mutation. Standardized case report forms were used for clinical and demographic data collection. We investigated the frequency of the most common substitution of LRRK2 (G2019S, 6055G>A) and its impact on epidemiological and phenotypic features. The frequency of mutations in Tunisian families was 42% (38/91) and in U.S. families 2.6% (1/39), with the unique opportunity to compare homozygous (n = 23) and heterozygous (n = 109) Tunisian carriers of G2019S substitutions. Individuals with G2019S substitutions had an older age at onset but few other differences compared with families negative for the substitution. Patients with LRRK2 mutations had typical clinical features of PD. Comparisons between individuals with heterozygous and homozygous LRRK2 mutations suggested that gene dosage was not correlated with phenotypic differences; however, the estimated penetrance was greater in homozygotes across all age groups.

Medical history, lifestyle, family history, and occupational risk factors for marginal zone lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Marginal zone lymphoma (MZL), comprised of nodal, extranodal, and splenic subtypes, accounts for 5%-10% of non-Hodgkin lymphoma cases. A detailed evaluation of the independent effects of risk factors for MZL and its subtypes has not been conducted.

METHODS

Data were pooled from 1052 MZL cases (extranodal [EMZL] = 633, nodal [NMZL] = 157, splenic [SMZL] = 140) and 13766 controls from 12 case-control studies. Adjusted unconditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Novel findings for MZL subtypes include increased risk for B-cell activating autoimmune conditions (EMZL OR = 6.40, 95% CI = 4.24 to 9.68; NMZL OR = 7.80, 95% CI = 3.32 to 18.33; SMZL OR = 4.25, 95% CI = 1.49 to 12.14), hepatitis C virus seropositivity (EMZL OR = 5.29, 95% CI = 2.48 to 11.28), self-reported peptic ulcers (EMZL OR = 1.83, 95% CI = 1.35 to 2.49), asthma without other atopy (SMZL OR = 2.28, 95% CI = 1.23 to 4.23), family history of hematologic cancer (EMZL OR = 1.90, 95% CI = 1.37 to 2.62) and of non-Hodgkin lymphoma (NMZL OR = 2.82, 95% CI = 1.33 to 5.98), permanent hairdye use (SMZL OR = 6.59, 95% CI = 1.54 to 28.17), and occupation as a metalworker (NMZL OR = 3.56, 95% CI = 1.67 to 7.58). Reduced risks were observed with consumption of any alcohol (EMZL fourth quartile OR = 0.48, 95% CI = 0.28 to 0.82) and lower consumption of wine (NMZL first to third quartile ORs < 0.45) compared with nondrinkers, and occupation as a teacher (EMZL OR = 0.58, 95% CI = 0.37 to 0.88).

CONCLUSION

Our results provide new data suggesting etiologic heterogeneity across MZL subtypes although a common risk of MZL associated with B-cell activating autoimmune conditions was found.

The Network Structure of Schizotypal Personality Traits

Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.

Attitudes to deceased organ donation and registration as a donor among minority ethnic groups in North America and the U.K.: a synthesis of quantitative and qualitative research

OBJECTIVES

A systematic review and synthesis of quantitative and qualitative research were undertaken to examine attitudes to deceased donation and registration as an organ donor among ethnic minorities in the U.K. and North America.

DESIGN

A systematic search and assessments of relevance and quality were conducted. Parallel syntheses were then undertaken of 14 quantitative and 12 qualitative papers followed by their integration. The synthesis was organised around five barriers that emerged as key issues: (1) knowledge regarding deceased donation and registration as a donor; (2) discussion of donation/registration with family members; (3) faith and cultural beliefs; (4) bodily concerns including disfigurement and intactness; and (5) trust in doctors and the health care system.

RESULTS

In all countries, knowledge of organ donation and registration remained low despite public campaigns, with African-Americans and Black African and Black Caribbean populations in the U.K. often regarding organ donation as a 'white' issue. Each of the four attitudinal barriers was also more prevalent among ethnic minorities compared with the majority population. However, the significance of trust and uncertainties regarding religion/faith differed between groups, reflecting salient aspects of ethnic identity and experiences. Differences were also identified within ethnic groups associated with age and generation, although respect for the views of elders often influenced younger peoples' willingness to donate.

CONCLUSION

There is a need for a more nuanced understanding of ethnicity and of variations in attitudes associated with country of origin, age/generation, socio-economic status and area of residence, to inform public campaigns and promote sensitive discussions with bereaved ethnic minority families. The traditional focus on knowledge and attitudes also requires to be complemented by a greater emphasis on organisational and service-related barriers and changes required to enhance ethnic minorities' access to registration as a donor and consent to deceased donation.

Characterization of the human skin resistome and identification of two microbiota cutotypes

BACKGROUND

The human skin microbiota is considered to be essential for skin homeostasis and barrier function. Comprehensive analyses of its function would substantially benefit from a catalog of reference genes derived from metagenomic sequencing. The existing catalog for the human skin microbiome is based on samples from limited individuals from a single cohort on reference genomes, which limits the coverage of global skin microbiome diversity.

RESULTS

In the present study, we have used shotgun metagenomics to newly sequence 822 skin samples from Han Chinese, which were subsequently combined with 538 previously sequenced North American samples to construct an integrated Human Skin Microbial Gene Catalog (iHSMGC). The iHSMGC comprised 10,930,638 genes with the detection of 4,879,024 new genes. Characterization of the human skin resistome based on iHSMGC confirmed that skin commensals, such as Staphylococcus spp, are an important reservoir of antibiotic resistance genes (ARGs). Further analyses of skin microbial ARGs detected microbe-specific and skin site-specific ARG signatures. Of note, the abundance of ARGs was significantly higher in Chinese than Americans, while multidrug-resistant bacteria ("superbugs") existed on the skin of both Americans and Chinese. A detailed analysis of microbial signatures identified Moraxella osloensis as a species specific for Chinese skin. Importantly, Moraxella osloensis proved to be a signature species for one of two robust patterns of microbial networks present on Chinese skin, with Cutibacterium acnes indicating the second one. Each of such "cutotypes" was associated with distinct patterns of data-driven marker genes, functional modules, and host skin properties. The two cutotypes markedly differed in functional modules related to their metabolic characteristics, indicating that host-dependent trophic chains might underlie their development.

CONCLUSIONS

The development of the iHSMGC will facilitate further studies on the human skin microbiome. In the present study, it was used to further characterize the human skin resistome. It also allowed to discover the existence of two cutotypes on the human skin. The latter finding will contribute to a better understanding of the interpersonal complexity of the skin microbiome. Video abstract.

Adult cephalometric norms for Saudi Arabians with a comparison of values for Saudi and North American Caucasians

When considering orthognathic surgery for adult Saudi Arabians, there are as yet no cephalometric norms available for use during treatment planning. Lateral cephalometric radiographs were taken for 48 Saudi adult patients (24 males, 24 females). All showed reasonably normal dental relationship, with no severe antero-posterior, vertical or transverse skeletal discrepancies. The age range was from 20 to 46 years. Angular and linear measurements were recorded and compared to a similar sample of North American caucasians. A set of cephalometric values for male and female Saudis were established and the differences between these and a North American sample are highlighted.

Medical history, lifestyle, family history, and occupational risk factors for peripheral T-cell lymphomas: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Accounting for 10%-15% of all non-Hodgkin lymphomas in Western populations, peripheral T-cell lymphomas (PTCL) are the most common T-cell lymphoma but little is known about their etiology. Our aim was to identify etiologic risk factors for PTCL overall, and for specific PTCL subtypes, by analyzing data from 15 epidemiologic studies participating in the InterLymph Consortium.

METHODS

A pooled analysis of individual-level data for 584 histologically confirmed PTCL cases and 15912 controls from 15 case-control studies conducted in Europe, North America, and Australia was undertaken. Data collected from questionnaires were harmonized to permit evaluation of a broad range of potential risk factors. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression.

RESULTS

Risk factors associated with increased overall PTCL risk with a P value less than .05 included: a family history of hematologic malignancies (OR = 1.92, 95% CI = 1.30 to 2.84); celiac disease (OR = 17.8, 95% CI = 8.61 to 36.79); eczema (OR = 1.41, 95% CI = 1.07 to 1.85); psoriasis (OR = 1.97, 95% CI = 1.17 to 3.32); smoking 40 or more years (OR = 1.92, 95% CI = 1.41 to 2.62); and employment as a textile worker (ever) (OR = 1.58, 95% CI = 1.05 to 2.38) and electrical fitter (ever) (OR = 2.89, 95% CI = 1.41 to 5.95). Exposures associated with reduced overall PTCL risk included a personal history of allergies (OR = 0.69, 95% CI = 0.54 to 0.87), alcohol consumption (ever) (OR = 0.64, 95% CI = 0.49 to 0.82), and having ever lived or worked on a farm (OR = 0.72, 95% CI = 0.55% to 0.95%). We also observed the well-established risk elevation for enteropathy-type PTCL among those with celiac disease in our data. Conclusions Our pooled analyses identified a number of new potential risk factors for PTCL and require further validation in independent series.

Immunogenicity of Vibrio cholerae O1 toxin-coregulated pili in experimental and clinical cholera

A functional tcpA gene, encoding the major subunit of toxin-coregulated pili (TCP), is necessary for Vibrio cholerae O1 Ogawa strain 395 to colonize the human intestine and confer protective immunity to virulent challenge. The immunogenicity of TCP and other antigens in experimental and naturally acquired cholera was determined. Seroconversion to cholera toxin (CT), whole cell preparations, and to Ogawa lipopolysaccharide but not to purified native TCP or to a TcpA mimiotope was found in volunteers. Local intestinal secretory immunoglobulin A from volunteers showed conversions to cholera toxin and lipopolysaccharide but not to TCP. Cholera patients in Indonesia showed a seroconversion rate to TCP of 3 of 6 and a seroconversion to a TcpA mimiotope of 1 of 6. Volunteer and patient sera showed similar vibriocidal seroconversions when assayed against either TCP-positive and TCP-negative V. cholerae O1 strains, suggesting that TCP do not contribute demonstrably to the vibriocidal antigen. We conclude that although seroconversion to TCP can occur in naturally acquired cholera, solid long-term protection can be engendered in the absence of a detectable anti-TCP immune response.

Medical history, lifestyle, family history, and occupational risk factors for mycosis fungoides and Sézary syndrome: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Mycosis fungoides and Sézary syndrome (MF/SS) are rare cutaneous T-cell lymphomas. Their etiology is poorly understood.

METHODS

A pooled analysis of 324 MF/SS cases and 17217 controls from 14 case-control studies from Europe, North America, and Australia, as part of the International Lymphoma Epidemiology Consortium (InterLymph) Non-Hodgkin Lymphoma (NHL) Subtypes Project, was carried out to investigate associations with lifestyle, medical history, family history, and occupational risk factors. Multivariate logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

We found an increased risk of MF/SS associated with body mass index equal to or larger than 30 kg/m(2) (OR = 1.57, 95% CI = 1.03 to 2.40), cigarette smoking for 40 years or more (OR = 1.55, 95% CI = 1.04 to 2.31), eczema (OR = 2.38, 95% CI = 1.73 to 3.29), family history of multiple myeloma (OR = 8.49, 95% CI = 3.31 to 21.80), and occupation as crop and vegetable farmers (OR = 2.37, 95% CI = 1.14 to 4.92), painters (OR = 3.71, 95% CI = 1.94 to 7.07), woodworkers (OR = 2.20, 95% CI = 1.18 to 4.08), and general carpenters (OR = 4.07, 95% CI = 1.54 to 10.75). We also found a reduced risk of MF/SS associated with moderate leisure time physical activity (OR = 0.46, 95% CI = 0.22 to 0.97).

CONCLUSIONS

Our study provided the first detailed analysis of risk factors for MF/SS and further investigation is needed to confirm these findings in prospective data and in other populations.