1
|
Mirmosayyeb O, Barzegar M, Afshari-Safavi A, Nehzat N, Heidari A, Emami P, Shaygannejad V. Evaluation of Month of Birth in Neuromyelitis Optica Spectrum Disorders (NMSOD) and Multiple Sclerosis (MS). Mult Scler Int 2021; 2021:8874999. [PMID: 34221508 PMCID: PMC8211531 DOI: 10.1155/2021/8874999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 03/13/2021] [Accepted: 06/04/2021] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMO) are chronic immune-mediated diseases in the central nervous system (CNS). Environmental factors such as month of birth can be a trigger for these diseases. Therefore, we conducted this study to compare the months of birth in MS and NMOSD patients with the control group. METHODS In this cross-sectional study, 2345 patients with MS, 220 NMOSD patients, and 2174 healthy subjects were enrolled. Demographic information such as age, sex, month of birth, and education in three groups was extracted from the database. The associations between month of birth and MS were studied by binary logistic regression with adjusting for the year of birth. RESULTS There was a reduced birth rate in September-October in NMOSD (OR = 0.309, 95% CI: 0.150-0.636; p < 0.001) and MS patients (OR = 0.470, 95% CI: 0.374-0.591; p < 0.001) compared to the general population. The birth rate in March-April in MS was higher than the control group (OR = 1.613, 95% CI: 1.324-1.964; p < 0.001). There was no difference in the birth month distribution between the NMOSD and MS patients. No significant difference in MOB among different MS types was found. CONCLUSION Our findings showed a decreasing risk of NMOSD and MS in individuals born in the autumn months and an increasing MS risk in spring. More studies are required to elucidate the association between the month of birth and risk of MS and NMOSD and the seasonality factors.
Collapse
Affiliation(s)
- Omid Mirmosayyeb
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Neurology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Universal Council of Epidemiology (UCE), Universal Scientific Education and Research Network (USERN), Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdi Barzegar
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Neurology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Alireza Afshari-Safavi
- Department of Biostatistics and Epidemiology, Faculty of Health, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Nasim Nehzat
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
- Universal Council of Epidemiology (UCE), Universal Scientific Education and Research Network (USERN), Tehran University of Medical Sciences, Tehran, Iran
| | - Afshin Heidari
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parisa Emami
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Vahid Shaygannejad
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Neurology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
2
|
Badihian N, Riahi R, Goli P, Badihian S, Poursafa P, Kelishadi R. Prenatal and perinatal factors associated with developing multiple sclerosis later in life: A systematic review and meta-analysis. Autoimmun Rev 2021; 20:102823. [PMID: 33866064 DOI: 10.1016/j.autrev.2021.102823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 02/06/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Both genetic and environmental factors play roles in Multiple Sclerosis (MS) etiopathogenesis. The relationship between prenatal/perinatal factors/exposures and future MS occurrence in the offspring remains controversial. Here, we aimed to review the available evidence on prenatal/perinatal factors associated with later MS occurrence. METHOD We performed systematic search of PubMed, Web of Science, and Scopus from inception to October 2020. We included original observational studies conducted on human participants addressing the association between prenatal/perinatal factors and MS occurrence. Data were extracted according to the PRISMA guideline. The adjusted odds ratio (OR) with 95% confidence interval (CI) was considered as the desired effect size. The heterogeneity was evaluated by Cochran's Q and I2 and the publication bias was assessed. We excluded gestational/neonatal vitamin D level, season of birth, and latitude because of recently published systematic reviews/meta-analyses on these subjects. RESULTS Overall, 2306 records were identified in the primary search. After excluding irrelevant studies, we evaluated 34 studies with contributing data on 100 prenatal/perinatal factors associated with an increased or decreased risk of MS occurrence. In the meta-analyses, we found no statistically significant associations between later MS occurrence in offspring and prenatal smoking exposure (OR = 1.01, 95% CI = 0.77-1.34), mode of delivery (OR = 0.90, 95% CI = 0.52-1.56), birth order (OR = 0.85, 95% CI = 0.72-1.00), and maternal age (OR = 1.34, 95% CI = 0.88-2.04). Paternal age and parents' marital status at the time of childbirth, maternal preeclampsia/ toxemia, forceps use, birth weight, plurality, and preterm birth were the other most studied factors, and none reported to affect MS risk. CONCLUSION We found that prenatal smoking exposure, mode of delivery, birth order, and maternal age do not affect risk of future MS development. Moreover, most of the other investigated factors were reported not to affect MS risk in the offspring.
Collapse
Affiliation(s)
- Negin Badihian
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Roya Riahi
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parvin Goli
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Shervin Badihian
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Parnian Poursafa
- Department of Cell and Molecular Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | - Roya Kelishadi
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
| |
Collapse
|
3
|
Lane M, Yadav V. Multiple Sclerosis. TEXTBOOK OF NATURAL MEDICINE 2020. [PMCID: PMC7348625 DOI: 10.1016/b978-0-323-43044-9.00199-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
4
|
Dobrakowski P, Bogocz M, Cholewa K, Rajchel M, Kapica-Topczewska K, Wawrzyniak S, Bartosik-Psujek H, Kułakowska A, Koziarska D, Adamczyk-Sowa M. Month of birth and level of insolation as risk factors for multiple sclerosis in Poland. PLoS One 2017; 12:e0175156. [PMID: 28384281 PMCID: PMC5383232 DOI: 10.1371/journal.pone.0175156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 03/21/2017] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Many studies have shown that people born in the spring are at a higher risk of developing multiple sclerosis (MS). This may be associated with lower levels of sun exposure, and consequently, lower levels of vitamin D3 during pregnancy. However, these relationships have not been verified thus far in any countries in Central Europe. OBJECTIVE The aim of our study was to determine the frequency distribution of births for each calendar month in patients suffering from MS in Poland. METHODS We analyzed data for 2574 patients diagnosed with MS (1758 women, 816 men) living in Poland for an extended period. We added corrections resulting from the frequency distribution of births for the years in which the patients were born. We applied the Hewitt test for seasonality with Rogerson modification for 3-, 4-, or 6-month pulses or periods. Moreover, we examined the average number hours of sunshine in every month of the year. RESULTS The rank-sums for successive 3- and 4-month segments indicated the period from September to December and from October to December as having a significantly lower incidence (p = 0.027 and p = 0.054, respectively). We did not find a correlation between with hours of sunshine in the first trimester of pregnancy, the child's birth month, and the child developing MS. CONCLUSIONS We were able to confirm a seasonal variation in the risk of MS in Poland. However, these findings did not correlate with hours of sunshine during the first trimester of pregnancy.
Collapse
Affiliation(s)
- Paweł Dobrakowski
- Department of Neurology in Zabrze, Medical University of Silesia, Zabrze, Poland
| | - Michał Bogocz
- Department of Neurology in Zabrze, Medical University of Silesia, Zabrze, Poland
| | - Kamil Cholewa
- Department of Neurology in Zabrze, Medical University of Silesia, Zabrze, Poland
| | - Mateusz Rajchel
- Department of Neurology in Zabrze, Medical University of Silesia, Zabrze, Poland
| | | | - Sławomir Wawrzyniak
- Department of Neurology, 10 Military Hospital with Policlinic, Bydgoszcz, Poland
| | | | - Alina Kułakowska
- Department of Neurology, Medical University of Białystok, Białystok, Poland
| | - Dorota Koziarska
- Department of Neurology, Pomeranian Medical University, Szczecin, Poland
| | - Monika Adamczyk-Sowa
- Department of Neurology in Zabrze, Medical University of Silesia, Zabrze, Poland
| |
Collapse
|
5
|
Season of birth and multiple sclerosis in Tunisia. Mult Scler Relat Disord 2015; 4:491-4. [DOI: 10.1016/j.msard.2015.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 11/18/2022]
|
6
|
Fragoso YD, Adoni T, Almeida SMGD, Alves-Leon SV, Arruda WO, Barbagelata-Aguero F, Brooks JBB, Carra A, Claudino R, Comini-Frota ER, Correa EC, Damasceno A, Damasceno BP, Díaz EC, Elliff DG, Fiore APP, Franco CMR, Giacomo MCB, Gomes S, Gonçalves MVM, Grzesiuk AK, Inojosa JL, Kaimen-Maciel DR, Lin K, Lopes J, Lourenço GA, Martínez AD, Melcon MO, Morales NDMO, Morales RR, Moreira M, Moreira SV, Oliveira CLDS, Oliveira FTMD, Ribeiro JB, Ribeiro SBF, Rodríguez CC, Russo L, Safanelli J, Shearer KD, Siquineli F, Vizcarra-Escobar D. Multiple sclerosis in South America: month of birth in different latitudes does not seem to interfere with the prevalence or progression of the disease. ARQUIVOS DE NEURO-PSIQUIATRIA 2014; 71:573-9. [PMID: 24141434 DOI: 10.1590/0004-282x20130098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 04/19/2013] [Indexed: 01/21/2023]
Abstract
OBJECTIVE To assess whether the month of birth in different latitudes of South America might influence the presence or severity of multiple sclerosis (MS) later in life. METHODS Neurologists in four South American countries working at MS units collected data on their patients' month of birth, gender, age, and disease progression. RESULTS Analysis of data from 1207 MS patients and 1207 control subjects did not show any significant variation in the month of birth regarding the prevalence of MS in four latitude bands (0-10; 11-20; 21-30; and 31-40 degrees). There was no relationship between the month of birth and the severity of disease in each latitude band. CONCLUSION The results from this study show that MS patients born to mothers who were pregnant at different Southern latitudes do not follow the seasonal pattern observed at high Northern latitudes.
Collapse
|
7
|
Fiddes B, Wason J, Sawcer S. Confounding in association studies: month of birth and multiple sclerosis. J Neurol 2014; 261:1851-6. [PMID: 24413643 PMCID: PMC4192561 DOI: 10.1007/s00415-014-7241-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 01/02/2014] [Indexed: 11/28/2022]
Abstract
Association studies form the backbone of biomedical research, with almost every effort in the field ultimately boiling down to a comparison between groups, coupled with some form of statistical test intended to determine whether or not any observed difference is more or less than would be expected by chance. Unfortunately, although the paradigm is powerful and frequently effective, it is often forgotten that false positive association can easily arise if there is any bias or systematic difference in the way in which study subjects are selected into the considered groups. To protect against such confounding, researchers generally try to match cases and controls for extraneous variables thought to correlate with the exposures of interest. However, if seemingly homogenously distributed exposures are actually more heterogeneous than appreciated, then matching may be inadequate and false positive results can still arise. In this review, we will illustrate these fundamental issues by considering the previously proposed relationship between month of birth and multiple sclerosis. This much discussed but false positive association serves as a reminder of just how heterogeneous even easily measured environmental risk factors can be, and how easily case control studies can be confounded by seemingly minor differences in ascertainment.
Collapse
Affiliation(s)
- Barnaby Fiddes
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0QQ, UK
| | | | | |
Collapse
|
8
|
Við Streym S, Rejnmark L, Mosekilde L, Vestergaard P. No effect of season of birth on risk of type 1 diabetes, cancer, schizophrenia and ischemic heart disease, while some variations may be seen for pneumonia and multiple sclerosis. DERMATO-ENDOCRINOLOGY 2013; 5:309-16. [PMID: 24194971 PMCID: PMC3772919 DOI: 10.4161/derm.22779] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/26/2012] [Accepted: 11/05/2012] [Indexed: 12/29/2022]
Abstract
Background: The risk of type 1 diabetes (T1DM), infections, cancer, schizophrenia and multiple sclerosis (MS) has been associated with environmental factors including vitamin D status.
Materials and Methods: Data were obtained from all children born in Denmark in 1940 (n = 72,839), 1977 (n = 89,570), and 1996 (n = 74,015). Information on contacts to hospitals (1977–2009) was obtained from the National Hospital Discharge Register. The main exposure variable was season of birth as a proxy variable for vitamin D status (summer: April–September and winter: October–March).
Results: No associations between season of birth and risk of MS were seen in the 1940 cohort or the 1996 cohort. In the 1977 cohort, there was a borderline statistically significant decreased risk of MS in those born during wintertime compared with those born during summertime (HR = 0.70, 95% CI: 0.47–1.04, p = 0.07). There were no significant differences within the groups regarding season and risk of T1DM at any age, T1DM before 10 y, infection, any type of cancer, schizophrenia and myocardial infarction. In the 1977 cohort the risk of pneumonia was significantly lower among those born in the summer compared with the winter at any age (HR 0.91, 95% CI 0.85–0.97, p < 0.01) and at age < 10 y (HR 0.90, 95% CI 0.84–0.97, p < 0.01).
Conclusion: MS and pneumonia in young subjects may be related to season of birth and thus maternal vitamin D exposure. Low sunlight exposure in the winter time leading to low vitamin D levels during pregnancy may be a potential explanation.
Collapse
Affiliation(s)
- Susanna Við Streym
- Department of Medicine and Endocrinology; MEA; THG; Aarhus University Hospital; Denmark
| | | | | | | |
Collapse
|
9
|
Torkildsen O, Grytten N, Aarseth J, Myhr KM, Kampman MT. Month of birth as a risk factor for multiple sclerosis: an update. Acta Neurol Scand 2013:58-62. [PMID: 23278658 DOI: 10.1111/ane.12040] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several studies have indicated month of birth as a risk factor for multiple sclerosis (MS) susceptibility and disease progression. METHODS We performed a systematic search on PubMed and Medline up to May 2012 using the search string 'multiple sclerosis' and 'month of birth' or 'season of birth'. In addition, congress abstracts and the reference lists of the publications identified were examined for further citations of relevance. RESULTS A total of fifteen published studies and two congress abstracts were found on the effect of month or season of birth on MS risk (sixteen in the northern and one in the southern hemisphere). Most studies in the northern hemisphere detected an excess of MS births in spring and a decrease in autumn. In the southern hemisphere, a reverse pattern was detected, with an excess in November and a decrease in April. Only three studies did not report any month of birth effect, all in low-risk areas for MS. Five studies have analysed a possible effect on disease course by month of birth. Of these, two studies reported an association between month of birth and age at onset of relapsing-remitting MS, with a younger disease onset for those born in the winter months. No consistent findings have been detected on the association between month of birth and disease progression. DISCUSSION The month of birth effect is consistently found to influence the risk of MS, and the effect seems to be most prominent in high-risk areas of the disease, especially in areas with low sunlight exposure. There seems to be little or no month of birth effects in areas with high sunlight exposure. These findings indicate a possible role for vitamin D concentrations during pregnancy or early life of the newborn. A possible effect of vitamin D supplementation needs to be further investigated.
Collapse
Affiliation(s)
- O Torkildsen
- Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway.
| | | | | | | | | |
Collapse
|
10
|
Pimentel MLV. Multiple sclerosis in the Southern and Northern hemispheres: the month of birth at different latitudes has the same influence on the prevalence and progression of the disease in the Northern and Southern hemispheres? ARQUIVOS DE NEURO-PSIQUIATRIA 2013; 71:569-70. [DOI: 10.1590/0004-282x20130114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 07/15/2013] [Indexed: 11/22/2022]
|
11
|
Araki Y, Kinoshita M, Motoyama R, Matsushita T, Nakagawa M, Kira JI, Tanaka M. Month of birth in multiple sclerosis with and without longitudinally extensive spinal cord lesions: A study of a Japanese national survey. J Neurol Sci 2013; 330:67-70. [DOI: 10.1016/j.jns.2013.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 04/07/2013] [Accepted: 04/10/2013] [Indexed: 11/30/2022]
|
12
|
Becker J, Callegaro D, Lana-Peixoto MA, Ferreira MLB, Melo A, Diniz da Gama P, Souza DG, Teixeira CA, Kaimen-Maciel DR, Gonçalves MV, Matta AP, Abraham R, Furtado LET, Lino A, Hauck L, Barreira AA, Gomes I. Season of birth as a risk factor for multiple sclerosis in Brazil. J Neurol Sci 2013; 329:6-10. [DOI: 10.1016/j.jns.2013.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 02/01/2013] [Accepted: 03/05/2013] [Indexed: 11/25/2022]
|
13
|
Verheul F, Smolders J, Trojano M, Lepore V, Zwanikken C, Amato MP, Grand'Maison F, Butzkueven H, Marrosu M, Duquette P, Comi G, Izquierdo G, Grammond P, Lus G, Petersen T, Bergamaschi R, Giuliani G, Boz C, Coniglio G, Van Pesch V, Lechner-Scott J, Cavalla P, Granella F, Avolio C, Fiol M, Poehlau D, Saladino ML, Gallo P, Deri N, Oleschko Arruda W, Paine M, Ferro M, Barnett M, Cabrera-Gomez JA, Slee M, Moore F, Shaw C, Petkovska-Boskova T, Rutherford M, Engelsen O, Damoiseaux J, Hupperts R. Fluctuations of MS births and UV-light exposure. Acta Neurol Scand 2013; 127:301-8. [PMID: 22970985 DOI: 10.1111/ane.12007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Patients with multiple sclerosis (MS) are more frequently born in spring when compared to autumn. Fluctuation of UV-light has been hypothesized to drive this phenomenon. AIM To assess the correlation between fluctuation of sunlight and birth season in persons with MS. METHODS For this record-linkage study, we collected from the international MSBase and the Italian MS iMed-web databases the dates of birth of 11,415 patients with MS from 36 centres from 15 countries worldwide and compared these to dates of live-births from national registries. From all participating sites, we collected data on UV-light fluctuation and assessed its correlation with seasonal fluctuation in MS births. RESULTS Compared with the reference cohort, an increased proportion of persons with MS were born in spring and a decreased proportion in autumn (odds ratio (OR) to be born in spring versus autumn = 1.158, χ² = 36.347, P < 0.001). There was no significantly increased fluctuation of MS births with increased quartile of ambient UV-light fluctuation (Ptrend = 0.086). CONCLUSION Seasonal fluctuation of MS births as found in this worldwide cohort of patients with MS did not correlate with variation in seasonal fluctuation of UV-light. Most likely, it results from a complex interplay between fluctuation of sunlight, behavioural factors, other environmental factors and (epi)genetic factors.
Collapse
Affiliation(s)
- F. Verheul
- Groene Hart Ziekenhuis; Gouda; The Netherlands
| | | | | | - V. Lepore
- Consorzio Mario Negri Sud; Santa Maria Imbaro; Italy
| | | | | | | | - H. Butzkueven
- Department of Medicine; Melbourne Brain Centre; University of Melbourne; Melbourne; Vic.; Australia
| | | | | | - G. Comi
- University of Milan; Milan; Italy
| | | | | | - G. Lus
- Second University of Naples; Naples; Italy
| | | | | | | | - C. Boz
- Karadeniz Technical University; Trabzon; Turkey
| | | | - V. Van Pesch
- Cliniques Universitaires Saint-Luc; Brussels; Belgium
| | | | | | | | | | - M. Fiol
- FLENI; Buenos Aires; Argentina
| | | | | | - P. Gallo
- University of Padova; Padova; Italy
| | - N. Deri
- Hospital Fernandez; Buenos Aires; Argentina
| | | | - M. Paine
- St Vincent's Hospital; Melbourne; Vic.; Australia
| | | | - M. Barnett
- Brain and Mind Research Institute; Sydney; NSW; Australia
| | | | - M. Slee
- Flinders Medical Centre; Bedford Park; SA; Australia
| | - F. Moore
- Jewish General Hospital; Montreal; Canada
| | - C. Shaw
- Geelong Hospital; Geelong; Vic.; Australia
| | | | | | - O. Engelsen
- Norwegian Institute for Air Research; Tromsø; Norway
| | - J. Damoiseaux
- Maastricht University Medical Center; Maastricht; The Netherlands
| | - R. Hupperts
- Orbis Medical Center; Sittard; The Netherlands
| |
Collapse
|
14
|
Barros P, de Sá JM, Sá MJ. Month of birth and risk of multiple sclerosis in a Portuguese population. Clin Neurol Neurosurg 2013; 115:1762-5. [PMID: 23643141 DOI: 10.1016/j.clineuro.2013.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 03/18/2013] [Accepted: 04/07/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND Several studies analyzing the month of birth (MOB) of multiple sclerosis (MS) patients and the risk of the disease have been published; as a whole, MS patients were found to be predominantly born in spring months, leading to the current assumption that MOB is somewhat related to the risk of MS. OBJECTIVE Estimate the risk of MS by MOB in a Portuguese population. METHODS MS patients sample was obtained from the database of patients attended at our MS clinic and born in the districts of Porto, Braga and Viana do Castelo. The control sample was composed of the live births records in the same time period and geographical area. We applied the Hewitt test for seasonality. RESULTS We found 421 patients that satisfied the conditions to enter the study. The rank-sums for successive 6-month segments indicate the July-December period as of higher incidence; however, the corresponding rank-sum (48) was not statistically significant according to the Hewitt test (p>0.05). CONCLUSION Our data does not support the seasonality hypothesis of MOB as risk factor for MS in Portugal. However we are aware that the analysis of a larger MS sample could shed more light in this issue.
Collapse
Affiliation(s)
- Pedro Barros
- Department of Neurology, Centro Hospitalar São João, 4200-319 Porto, Portugal.
| | | | | |
Collapse
|
15
|
Grytten N, Torkildsen Ø, Aarseth JH, Benjaminsen E, Celius EG, Dahl OP, Holmøy T, Løken-Amsrud K, Midgard R, Myhr KM, Risberg G, Vatne A, Kampman MT. Month of birth as a latitude-dependent risk factor for multiple sclerosis in Norway. Mult Scler 2012; 19:1028-34. [PMID: 23257620 DOI: 10.1177/1352458512471094] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE We aimed to determine if the risk of Multiple Sclerosis (MS) is associated with month of birth in Norway and to explore a possible latitudinal gradient. METHODS All patients with MS born between 1930 and 1979 registered in the Norwegian MS Registry or ascertained in Norwegian prevalence studies were included (n = 6649). The latitude gradient was divided in Southern, Middle and Northern Norway, according to the estimated regional yearly mean vitamin D effective UV dose. RESULTS Risk of MS was 11% higher for those born in April (p = 0.045), and 5% higher for those born in May (p = 0.229), 5% lower for those born in November (p = 0.302) and 12% lower for those born in February (p = 0.053) compared with the corresponding population, unaffected mothers and siblings. In Southern Norway the odds ratio of MS births in April and May was 1.05 (0.98-1.24), in Middle Norway 1.11 (0.97-1.27) and in Northern Norway 1.28 (1.0-1.63) compared with the other months. CONCLUSIONS This study confirms previous reports of increased MS births in spring and decreased MS births in the winter months. This could support the role of decreased sunlight exposure during pregnancy and vitamin D deficiency in prenatal life in MS.
Collapse
Affiliation(s)
- Nina Grytten
- Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Menni C, Lowell WE, Bentzen J, Bergamaschi R, Martinelli Boneschi F, Martinelli V, Bernardinelli L, Stenager E, Davis GE, Foco L. Short and long term variation in ultraviolet radiation and multiple sclerosis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2012; 9:685-97. [PMID: 22690156 PMCID: PMC3367270 DOI: 10.3390/ijerph9030685] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 02/16/2012] [Accepted: 02/16/2012] [Indexed: 12/23/2022]
Abstract
We examined the role of ultraviolet radiation (UVR) in persons diagnosed with multiple sclerosis (MS) in four different populations, Italians, Danish, White and African Americans. We tested whether variation in UVR as determined by seasons (short term variation) and solar cycles (long term variation) is related to MS birth month and to survival as measured by lifespan. Cases were selected from three Italian MS Case Registries (2,737); from the United States National Center for Health Statistics (56,020); and from the Danish Multiple Sclerosis registry (15,900). Chi-square tests were used to study the pattern of month of birth distribution in patients with MS comparing with general population data. T-tests were employed to study solar cycles association with lifespan. A surplus of births was observed in June for White Americans. A decrease of births in October and November, though not significant after multiple testing correction, was observed in the three populations. In White American with MS overall, males and females, we found that solar cycle is associated with lifespan. We found that season and solar cycles have some role in MS susceptibility and life duration. However, this is an exploratory analysis and further work is needed to discern the association.
Collapse
Affiliation(s)
- Cristina Menni
- Department of Applied Health Sciences, University of Pavia, Via Bassi 21, 27100 Pavia, Italy; (L.B.); (L.F.)
| | - Walter E. Lowell
- Psybernetics Research Group, 04330 Augusta, Maine, USA; (W.E.L.); (G.E.D.)
| | - Joan Bentzen
- The Danish Multiple Sclerosis Registry, National Institute of Public Health, 1353 Copenhagen, Denmark; (J.B.); (E.S.)
| | - Roberto Bergamaschi
- Neurological Institute Casimiro Mondino, Interdepartment Research Center for Multiple Sclerosis, 27100 Pavia, Italy;
| | | | - Vittorio Martinelli
- Department of Neuro-Rehabilitation, Scientific Institute San Raffaele, 20100 Milan, Italy; (F.M.B.); (V.M.)
| | - Luisa Bernardinelli
- Department of Applied Health Sciences, University of Pavia, Via Bassi 21, 27100 Pavia, Italy; (L.B.); (L.F.)
- Department of Pure Mathematics and Mathematical Statistics, University of Cambridge, CB3 0WA Cambridge, UK
| | - Egon Stenager
- The Danish Multiple Sclerosis Registry, National Institute of Public Health, 1353 Copenhagen, Denmark; (J.B.); (E.S.)
- Institute of Regional Health Services, University of Southern Denmark, 5000 Odense, Denmark
- MS-Clinic of Southern Jutland (Sonderborg, Vejle, Esbjerg), Department of Neurology, 6400 Sonderborg, Denmark
| | - George E. Davis
- Psybernetics Research Group, 04330 Augusta, Maine, USA; (W.E.L.); (G.E.D.)
| | - Luisa Foco
- Department of Applied Health Sciences, University of Pavia, Via Bassi 21, 27100 Pavia, Italy; (L.B.); (L.F.)
| |
Collapse
|
17
|
Abstract
Multiple sclerosis (MS) is the most common disease of the central nervous system that causes permanent disability in young adults. Based on strong circumstantial evidence, MS is considered to be putative autoimmune disorder, but much remains to be understood about the etiology and clinical onset of the disease. It seems unlikely that MS results from a single causative event, but rather is the result of genetic and environmental factors and the interactions thereof. This article discusses the epidemiology of MS.
Collapse
Affiliation(s)
- Sreeram V Ramagopalan
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | | |
Collapse
|
18
|
Staples J, Ponsonby AL, Lim L. Low maternal exposure to ultraviolet radiation in pregnancy, month of birth, and risk of multiple sclerosis in offspring: longitudinal analysis. BMJ 2010; 340:c1640. [PMID: 21030361 PMCID: PMC2862149 DOI: 10.1136/bmj.c1640] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVES To investigate the distribution of month of birth in people with multiple sclerosis in Australia. To use the large regional and seasonal variation in ambient ultraviolet radiation in Australia to explore the association between exposure to ultraviolet radiation during pregnancy and subsequent risk of multiple sclerosis in offspring. DESIGN Data were gathered on birth month and year (1920-1950), sex, and state of birth for all patients surveyed in 1981 in Queensland, Western Australia, New South Wales (including Australian Capital Territory), South Australia, and Hobart (Tasmania). Population denominators were derived from the 1981 census and supplementary birth registration data. A variable for exposure to ambient ultraviolet radiation "at birth" was generated from monthly averages of daily total ambient ultraviolet radiation for each region. Negative binomial regression models were used to investigate exposure to ambient ultraviolet radiation at birth and at various intervals before birth. SETTING Patient data from multiple sclerosis prevalence surveys carried out in 1981; 1981 Australian census (giving the total number of people born in Australia and still alive and living in Australia in 1981 by year of birth 1920-50); supplementary Australian birth registration data covering the same birth years by month and state. PARTICIPANTS 1524 patients with multiple sclerosis born in Australia 1920-50 from total population of 2 468 779. MAIN OUTCOME MEASURE Cumulative incidence rate of multiple sclerosis. RESULTS There was a pattern of risk of multiple sclerosis with month of birth (adjusted incidence rate ratio 1.32, 95% confidence interval 1.10 to 1.58, P<0.01, for those born in November-December compared with those born in May-June). This pattern mirrored that previously reported in the northern hemisphere. Region of birth was related to risk. After adjustment for region of birth and other factors, there was an inverse association between ambient ultraviolet radiation in the first trimester and risk of multiple sclerosis (with ≥25 erythemal (skin reddening) dose units as reference (that is, adjusted incidence rate ratio=1.00), the rates were 1.54 (1.10 to 2.16) for 20-<25 units; 1.58 (1.12 to 2.22) for 15-<20 units; 1.65 (1.17 to 2.33) for 10-<15 units; 1.65 (1.18 to 2.29) for 5-<10 units; and 1.67 (1.18 to 2.37) for <5 units). After adjustment for this exposure during early pregnancy, there was no residual association between month of birth and multiple sclerosis. CONCLUSION Region of birth and low maternal exposure to ultraviolet radiation in the first trimester are independently associated with subsequent risk of multiple sclerosis in offspring in Australia.
Collapse
Affiliation(s)
- Judith Staples
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia
| | | | | |
Collapse
|
19
|
Fernandes de Abreu DA, Babron MC, Babron MCI, Rebeix I, Rebeix C, Fontenille C, Fontenille J, Yaouanq J, Yaouanq D, Brassat D, Brassat B, Fontaine B, Fontaine F, Clerget-Darpoux F, Jehan F, Feron F. Season of birth and not vitamin D receptor promoter polymorphisms is a risk factor for multiple sclerosis. Mult Scler 2009; 15:1146-52. [PMID: 19965563 DOI: 10.1177/1352458509106780] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Both genetic and environmental factors contribute to multiple sclerosis, the most common neurodegenerative disorder with onset in young adults. The objective of the current study is, based on the hypothesis that environmentally predisposed individuals are at risk for multiple sclerosis, to investigate whether they also carry genetic variants within the vitamin D machinery. Using medical files and DNA samples from 583 trios (a patient and both parents) of the French Multiple Sclerosis Genetics Group as well as data from the French Statistics Bureau, we aimed to assess whether: (1) a seasonality of birth was observed in French multiple sclerosis patients; (2) three single nucleotide polymorphisms within the promoter region of the vitamin D receptor were associated with multiple sclerosis susceptibility; and (3) the combination of a high risk month of birth and vitamin D receptor polymorphisms were correlated to multiple sclerosis incidence. We observed a significantly reduced number of individuals born in November who were later diagnosed as multiple sclerosis patients. However, we found no association between the three studied vitamin D receptor polymorphisms and multiple sclerosis. In conclusion, our data suggest that high levels of vitamin D during the third trimester of pregnancy could be a protective factor for multiple sclerosis.
Collapse
Affiliation(s)
- D A Fernandes de Abreu
- Neurobiologie des Interactions Cellulaires et Neurophysiopathologie (NICN), CNRS UMR 6184, IFR Jean Roche, Faculté de Médecine Nord, Marseille, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Koch HJ, Strobl D, Steinbrecher A. Seasonal pattern of births in patients with multiple sclerosis. BIOL RHYTHM RES 2008. [DOI: 10.1080/09291010701590026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
21
|
Ponsonby AL, Lucas RM, van der Mei IAF. UVR, vitamin D and three autoimmune diseases--multiple sclerosis, type 1 diabetes, rheumatoid arthritis. Photochem Photobiol 2006; 81:1267-75. [PMID: 15971932 DOI: 10.1562/2005-02-15-ir-441] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We review the evidence indicating a possible beneficial role for UVR on three Th1-mediated autoimmune diseases: multiple sclerosis, type 1 diabetes and rheumatoid arthritis in relation to recent developments in photoimmunology. Recent work suggests that UVR exposure may be one factor that can attenuate the autoimmune activity leading to these three diseases through several pathways involving UVB and UVA irradiation, UVR-derived vitamin D synthesis and other routes such as alpha-melanocyte-stimulating hormone, calcitonin gene related peptide and melatonin. Ecological features, particularly a gradient of increasing prevalence of multiple sclerosis and type 1 diabetes with higher latitude, provide some support for a beneficial role of UVR. Analytical studies provide additional support, particularly as low vitamin D has been prospectively associated with disease onset for all three diseases, but are not definitive. Randomized controlled trial data are required. Further, we discuss how associated genetic studies may assist the accumulation of evidence with regard to the possible causal role of low UVR exposure and/or low vitamin D status in the development of these diseases.
Collapse
Affiliation(s)
- A-L Ponsonby
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Melbourne, Australia.
| | | | | |
Collapse
|
22
|
Sotgiu S, Pugliatti M, Sotgiu MA, Fois ML, Arru G, Sanna A, Rosati G. Seasonal fluctuation of multiple sclerosis births in Sardinia. J Neurol 2005; 253:38-44. [PMID: 16021348 DOI: 10.1007/s00415-005-0917-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2004] [Revised: 02/10/2005] [Accepted: 02/22/2005] [Indexed: 10/25/2022]
Abstract
Study results from different geographical areas provide some circumstantial evidence that, when compared with the general population, people who later in life develop multiple sclerosis (MS) have a pattern of birth excess numbers in spring and late summer, which may disclose an association with MS-predisposing environmental agents. To identify the presence of season-related cluster of MS birth in Sardinia we have designed a case-control study in the province of Sassari, Northern Sardinia, insular Italy, an area at very-high and increasing risk for MS. Mean birth incidence rate of people with MS (810 cases) on a three-and six-months basis were compared with that of two control populations: the MS unaffected siblings (1069), sharing genetic material with patients, and a representative number of births (247,612) of the general population of the study area. We found that the birth in months peaking in spring significantly represents one risk factor for future MS development. This seasonal deviation of MS births reveals an intriguing epidemiological overlap with common environmental agents, which may open a new scenario of hypothetical explanations for environmental factors perhaps affecting the CNS at the crucial time of myelination or shaping the newborn immune system.
Collapse
Affiliation(s)
- Stefano Sotgiu
- Istituto di Clinica Neurologica, Università di Sassari, Viale San Pietro, 10, 07100, Sassari, Italy.
| | | | | | | | | | | | | |
Collapse
|
23
|
Willer CJ, Dyment DA, Sadovnick AD, Rothwell PM, Murray TJ, Ebers GC. Timing of birth and risk of multiple sclerosis: population based study. BMJ 2005; 330:120. [PMID: 15585537 PMCID: PMC544426 DOI: 10.1136/bmj.38301.686030.63] [Citation(s) in RCA: 327] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To determine if risk of multiple sclerosis (MS) is associated with month of birth in countries in the northern hemisphere and if factors related to month of birth interact with genetic risk. DESIGN Population based study with population and family based controls and a retrospective cohort identified from death certificates. A post hoc pooled analysis was carried out for large northern datasets including Sweden and Denmark. SETTING 19 MS clinics in major cities across Canada (Canadian collaborative project on the genetic susceptibility to multiple sclerosis); incident cases of MS from a population based study in the Lothian and Border regions of Scotland; and death records from the UK Registrar General. POPULATIONS 17,874 Canadian patients and 11,502 British patients with multiple sclerosis. MAIN OUTCOME MEASURE Diagnosis of multiple sclerosis. RESULTS In Canada (n = 17,874) significantly fewer patients with MS were born in November compared with controls from the population census and unaffected siblings. These observations were confirmed in a dataset of British patients (n = 11, 502), in which there was also an increase in the number of births in May. A pooled analysis of datasets from Canada, Great Britain, Denmark, and Sweden (n = 42,045) showed that significantly fewer (8.5%) people with MS were born in November and significantly more (9.1%) were born in May. For recent incident data, the effect of month of birth was most evident in Scotland, where MS prevalence is the highest. CONCLUSIONS Month of birth and risk of MS are associated, more so in familial cases, implying interactions between genes and environment that are related to climate. Such interactions may act during gestation or shortly after birth in individuals born in the northern countries studied.
Collapse
Affiliation(s)
- Cristen J Willer
- Department of Biostatistics, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | | | | | |
Collapse
|
24
|
Chaudhuri A. Why we should offer routine vitamin D supplementation in pregnancy and childhood to prevent multiple sclerosis. Med Hypotheses 2005; 64:608-18. [PMID: 15617877 DOI: 10.1016/j.mehy.2004.06.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2004] [Accepted: 06/24/2004] [Indexed: 10/26/2022]
Abstract
Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that runs a chronic course and disables young people. The disease is more prevalent in the geographic areas that are farthest from the equator. No form of treatment is known to be effective in preventing MS or its disabling complications. A number of epidemiological studies have shown a protective effect of exposure to sunlight during early life and a recent longitudinal study confirmed that vitamin D supplementation reduced life-time prevalence of MS in women. Very little is known regarding the role of vitamin D on the developing brain but experimental data suggest that cerebral white matter is vitamin D responsive and oligodendrocytes in the brain and spinal cord and express vitamin D receptors. It is possible that differentiation and axonal adhesion of oligodendrocytes are influenced by vitamin D level during brain development and a relative lack of vitamin D may increase oligodendroglial apoptosis. The age effect of migration on susceptibility to develop MS could be explained by a role of vitamin D on brain development. In areas of high MS prevalence, dietary supplementation of vitamin D in early life may reduce the incidence of MS. In addition, like folic acid, vitamin D supplementation should also be routinely recommended in pregnancy. Prevention of MS by modifying an important environmental factor (sunlight exposure and vitamin D level) offers a practical and cost-effective way to reduce the burden of the disease in the future generations.
Collapse
Affiliation(s)
- Abhijit Chaudhuri
- Department of Neurology, Institute of Neurological Sciences, 1345 Govan Road, Glasgow G51 4TF, UK.
| |
Collapse
|
25
|
Ponsonby AL, McMichael A, van der Mei I. Ultraviolet radiation and autoimmune disease: insights from epidemiological research. Toxicology 2002; 181-182:71-8. [PMID: 12505287 DOI: 10.1016/s0300-483x(02)00257-3] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This review examines the epidemiological evidence that suggests ultraviolet radiation (UVR) may play a protective role in three autoimmune diseases: multiple sclerosis, insulin-dependent diabetes mellitus and rheumatoid arthritis. To date, most of the information has accumulated from population studies that have studied the relationship between geography or climate and autoimmune disease prevalence. An interesting gradient of increasing prevalence with increasing latitude has been observed for at least two of the three diseases. This is most evident for multiple sclerosis, but a similar gradient has been shown for insulin-dependent diabetes mellitus in Europe and North America. Seasonal influences on both disease incidence and clinical course and, more recently, analytical studies at the individual level have provided further support for a possible protective role for UVR in some of these diseases but the data are not conclusive. Organ-specific autoimmune diseases involve Th1 cell-mediated immune processes. Recent work in photoimmunology has shown ultraviolet B (UVB) can specifically attenuate these processes through several mechanisms which we discuss. In particular, the possible contribution of an UVR-induced increase in serum vitamin D (1,25(OH)2D3) levels in the beneficial immunomodulation of these diseases is discussed.
Collapse
Affiliation(s)
- Anne-Louise Ponsonby
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra ACT 0200, Australia.
| | | | | |
Collapse
|
26
|
Fritzsche M. Geographical and seasonal correlation of multiple sclerosis to sporadic schizophrenia. Int J Health Geogr 2002; 1:5. [PMID: 12537588 PMCID: PMC149400 DOI: 10.1186/1476-072x-1-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2002] [Accepted: 12/20/2002] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND: Clusters by season and locality reveal a striking epidemiological overlap between sporadic schizophrenia and multiple sclerosis (MS). As the birth excesses of those individuals who later in life develop schizophrenia mirror the seasonal distribution of Ixodid ticks, a meta analysis has been performed between all neuropsychiatric birth excesses including MS and the epidemiology of spirochaetal infectious diseases. RESULTS: The prevalence of MS and schizophrenic birth excesses entirely spares the tropical belt where human treponematoses are endemic, whereas in more temperate climates infection rates of Borrelia garinii in ticks collected from seabirds match the global geographic distribution of MS. If the seasonal fluctuations of Lyme borreliosis in Europe are taken into account, the birth excesses of MS and those of schizophrenia are nine months apart, reflecting the activity of Ixodes ricinus at the time of embryonic implantation and birth. In America, this nine months' shift between MS and schizophrenic births is also reflected by the periodicity of Borrelia burgdorferi transmitting Ixodes pacificus ticks along the West Coast and the periodicity of Ixodes scapularis along the East Coast. With respect to Ixodid tick activity, amongst the neuropsychiatric birth excesses only amyotrophic lateral sclerosis (ALS) shows a similar seasonal trend. CONCLUSION: It cannot be excluded at present that maternal infection by Borrelia burgdorferi poses a risk to the unborn. The seasonal and geographical overlap between schizophrenia, MS and neuroborreliosis rather emphasises a causal relation that derives from exposure to a flagellar virulence factor at conception and delivery. It is hoped that the pathogenic correlation of spirochaetal virulence to temperature and heat shock proteins (HSP) might encourage a new direction of research in molecular epidemiology.
Collapse
Affiliation(s)
- Markus Fritzsche
- Clinic for Internal Medicine, Soodstrasse 13, 8134 Adliswil, Switzerland.
| |
Collapse
|