Idiopathic epilepsy is a world-wide neurological upset that affects people of assorted ages. However surveies of herpesvirus infections in grownup epilepsy patients are still rare. This survey was performed to place the association between epilepsy and herpesvirus IgG antibodies. A cross-sectional survey was conducted with serum samples obtained from epilepsy patients ( n=95 ) and healthy controls ( n=95 ) upon carry throughing the inclusion and exclusion standards. The presence of specific IgG antibodies against herpes simplex virus type 1 and type 2 ( HSV-1,2 ) , varicella-zoster virus ( VZV ) , CMV ( CMV ) and Epstein-Barr virus ( EBV ) were detected by enzyme linked immunosorbent check ( ELISA ) trial kits. Among all the herpesvirus studied, merely CMV IgG degree showed important association to epilepsy ( X2=186.0 ; P & lt ; 0.001 ) . It can be concluded that CMV infection possibly one of the factors that contributes to epilepsy. This relationship between CMV and epilepsy should be more extensively studied to look into its mechanism in active infections.
Cardinal words: CMV, epilepsy, Epstein-Barr virus, herpes simplex virus, chickenpox shingles virus
Epilepsy is a neurological upset that affects people of assorted ages in more than 50 million person throughout the whole universe 1. The World Health Organization estimated between 4 to 10 per 1000 persons worldwide suffer from this disease 2 with a higher prevalence reported in developing states 3.
Epilepsy affects both work forces and adult females of all ages, races and socioeconomic degrees. Majority of the instances are idiopathic while the remainder may be due to certain aggravated signifiers such as traumatic encephalon hurt, metabolic mental unsoundnesss, drugs withdrawal, alcohol consumption, intellectual infarction and cardinal nervous system ( CNS ) infection 3.
The cause of epilepsy remains elusive. Some surveies link the immune system with epilepsy 4,5 while others try to associate virus infection to the ictuss 6,7. Herpesvirus as aetiological agents of epilepsy have gained much attending due to the fact that the viruses have the inclination to set up latent and womb-to-tomb infections in human 8-10. They may come in CNS via endothelial cells run alonging the blood vass or may come in within lymph cells and macrophages that they infect at the peripheral nerve cells 6. To the best of our cognition, most surveies had focused on newborns and kids. Therefore, this survey was conducted to find the association between grownup epilepsy patients and infection with herpesvirus, viz. herpes simplex virus type 1 and herpes simplex virus type 2 ( HSV-1 and HSV-2 ) , varicella-zoster virus ( VZV ) , CMV ( CMV ) and Epstein-Barr virus ( EBV ) .
2. Materials and methods
2.1 Study topics
A cross-sectional survey was carried out on 95 epilepsy patients and 95 healthy topics which started in March 2008 boulder clay February 2009. All epilepsy patients and healthy topics were enrolled from the Hospital Universiti Sains Malaysia ( HUSM ) which is located in the Kota Bharu territory of the Kelantan province of Malaysia. Ninety-four per centum of the Kelantanese population are Malays 11, with about two 3rd of the population life in the rural countries 12. This survey had obtained an ethical blessing from the local establishment of Universiti Sains Malaysia ( USM ) .
A simple random trying method was used to enroll epilepsy patients from a Medical Specialist Clinic, HUSM, whereby one in every four patients go toing the clinic were selected after being screened utilizing the inclusion and exclusion standards. The inclusion standards include epilepsy patients aged between 18 and 50 old ages old that were for a everyday medical check-up. The diagnosing of epilepsy and ictus type was confirmed by a qualified go toing Neurologist based on electroencephalography ( EEG ) and magnetic resonance imagination ( MRI ) trials. Patients who were holding febrility and those who were pregnant or holding history of organic encephalon upsets, autoimmune disease, chronic infections and underlying malignances or other acute infections were excluded.
Healthy topics were selected from the populace largely those who are attach toing their relations or friends who came for the check-ups. They were recruited into the survey whenever they fulfil the inclusion and exclusion demands and agreeable to be included. The inclusion standards include healthy individual aged between 18-50 old ages old with no medical unwellness, while those who are pregnant, holding underlying medical unwellness, feverish tantrum, holding febrility or acute infections or on hospital prescriptions were wholly excluded.
2.2 Blood samples
Blood samples ( 3 milliliter ) were collected into apparent tubings from the peripheral vena of the survey topics. Serum was separated shortly after being centrifuged at 1500 g for 5 proceedingss following 6 hours of incubation at room temperature ( 27A°C ) . The gathered serum was kept at -80A°C prior to proving by ELISA check.
2.3 ELISA Procedure
Indirect ELISA trials were carried out to quantify antibodies against herpes viral antigens following the maker ‘s protocols. All ELISA kits ( PlateliaTM HSV ( 1+2 ) IgG, PlateliaTM VZV IgG, PlateliaTM CMV IgG, PlateliaTM EBV-VCA IgG ) were supplied by the BIO-RAD Laboratories Company ( California, USA ) . The trial processs for all the ELISA kits are fundamentally similar, except for PlateliaTM EBV-VCA IgG, where there was a little difference in footings of incubation period and rinsing times.
Briefly, diluted patients serum ( 1:101 ) was placed in the specified good, every bit good as the calibrators. The ELISA home bases were so incubated for 45 min at room temperature to let the Igs to adhere to the antigen before rinsing for several times to extinguish any residuary unreacted proteins.
Further incubation was carried out with the conjugate ( human IgG monoclonal antibodies labelled with peroxidase ) for another 45 min before rinsing. The unbound conjugate was discarded and the peroxidised substrate ( 20 Aµl ) was added.
The developed coloring material was relative to the concentration of specific antibodies present in the serum sample. The optical density ( O.D. ) was detected utilizing the ELISA Analyser and the values were calculated and compared against the qualitative cut-off provided for each commercial ELISA kits used. This was to place whether the topics have specific antibody against viral antigen studied.
The statistical analyses were performed utilizing SPSS package version 12.0 ( SPSS Inc. , Illinois, US ) . Normality was determined for age and gender for both survey groups. The association between herpes virus and epileptic patients were analyzed via the Pearson ‘s Chi-Square trial and Fischer ‘s Exact trial and P value & lt ; 0.05 was considered to be statistically important.
3.1 Sociodemographic factors.
A normal distribution were obtained for both groups of epilepsy patients ( n=95 ) and healthy controls ( n=95 ) . The sociodemographic factors that include age, gender, ethnicity and instruction degree were calculated and compared between both survey groups ( Table 1 ) . Male and female distribution for epilepsy group is besides usually distributed with the ratio of male to female was 1.2:1. Seventy nine per centum of the epilepsy patients came from rural countries whereas the staying 11 % were from the urban countries. Majority of the healthy controls ( 73 % ) were besides from rural countries which are comparable to epilepsy patients in footings of survey population. The age at first ictus oncoming, type of ictus, happening of feverish tantrums and household history of epilepsy upset were obtained and analysed ( Table 1 ) . The average age at first ictus oncoming is 15.58 old ages. All epilepsy patients were diagnosed to be enduring from idiopathic epilepsy with no identifiable causes present. 80 out of the 95 patients had temporal lobe epilepsy with or without secondary generalization. Single half hr recording of EEG picked up temporal lobe focal point in 35 patients, 14 on the right side and 21 on the left side. “ PLEASE INSERT TABLE I HERE ”
3.2 The association between epilepsy and old herpes virus infection.
Among the specific IgG of the four herpesvirus reported in this survey, merely CMV IgG showed an association with epileptic topics ( ??2 = 186.0 ; P & lt ; 0.001 ) ( Table II ) . The highly high X2 value among CMV infected epileptic patients suggests a strong association between CMV and epilepsy. The specific IgG consequences of the survey topics are illustrated in Figure I.
“ PLEASE INSERT TABLE II AND FIGURE I HERE ”
The findings from this survey showed that less than 10 % of the epilepsy patients had household history of their close relations ( parents or siblings ) enduring from similar upset. This consequence suggests that familial heritage is non a major cause lending to epilepsy 13 and there is possibility that some other causative factor plays a function in its pathogenesis.
Harmonizing to our survey, antibody against CMV IgG infection was significantly associated with epilepsy whereas VZV IgG, EBV IgG and HSV ( 1+2 ) IgG were non. A old survey utilizing polymerase concatenation reaction ( PCR ) on hippocampal encephalon tissue samples from patients with temporal lobe epilepsy ( TLE ) found that 25 % of the survey topics were positive for CMV DNA 14. Another survey utilizing unmoved hybridisation method on encephalon tissue biopsy of Rasmussen Syndrome patients found that 70 % of their survey topics were positive for CMV DNA 15. Our present survey on the sensing of herpesvirus specific IgG from peripheral serum samples clearly shows that presence of CMV antibody is significantly related to all the epilepsy patients. However, since merely 36.8 % of our survey topics suffered from TLE we think that this could be the ground ( apart from the different method used ) for the difference seen when comparing the consequences of this survey to the above mentioned surveies.
Suzuki et Al. ( 2008 ) on the other manus, studied epilepsy in inborn CMV and found that seven of 19 topics with inborn CMV developed epilepsy 16. The findings were found to be congruous with our present survey when looking at the relationship between CMV and epilepsy, nevertheless we could non state whether our epilepsy patients were infected by CMV during babyhood ( inborn ) as the relevant information is non soon available.
Cytomegalovirus is omnipresent and infections are normally acquired really early during childhood with bulk of the infections symptomless. Four point two per centum of our epilepsy patients experienced feverish tantrums during their childhood, but bulk of survey topics had their first ictus onset at the average age of 16 old ages old. Most research workers agrees on the fact that the hazard to develop epilepsy following episodes of feverish tantrum is rather little and non important 17, merely 2-10 % , depending on the type of feverish tantrum they encountered 18. Furthermore, merely about 10-15 % of CMV infected babies really present with the clinical symptoms while the remainder remains symptomless 10,16.
A old study 19 found that kids from low socioeconomic backgrounds have a higher incidence of being infected with CMV when compared to those who lived in the urban countries ; which is comparable to our survey whereby bulk of the patients came from rural countries.
A sum of 98.9 % of survey topics studied were found to be immune to EBV. This is comparable to a survey conducted by Norzuriza et Al. ( 2008 ) who found that 77.5 % of the populace in Malaysia between the age 0-20 old ages, and 100 % of people aged above 60 old ages had old infection with EBV 20. A similar survey conducted in Bangladesh showed that 85 % of the survey group had positive EBV IgG after the age of 10 21 while a research in Papua New Guinea reported that about 93 % people in urban countries and 98 % people in rural countries were positive for EBV antibodies 22. Infections with EBV is therefore really common, with the prevalence varies among different states due to environmental, geographical, socioeconomic and hygienic conditions 23.
Eighty-seven per centum of our survey topics, both control and epilepsy group were found to be immune to VZV, most likely as the consequence of old poulet syphilis and herpes zosters. This consequence is comparable to a study that stated a close 100 % seropositivity to VZV in USA 24. Varicella-zoster virus infection is besides every bit common as EBV with childhood infection the norm ; chicken syphilis being the usual clinical manifestation even though terrible infection may happen in immunocompromised patients 10,24.
The proportion of survey topics with HSV specific antibody is comparatively high in both groups, even though non significantly associated to epilepsy. The former consequence is comparable with a old survey that showed a HSV specific antibodies prevalence of 61.4 % in the peninsular portion of Malaysia 25.
As a decision, our findings revealed that there is a important association between epilepsy and CMV IgG that suggests old CMV infections may play a function in lending to the pathogenesis of epilepsy. Therefore, CMV infections among epilepsy patients should be more extensively studied to look into its mechanism and map in active and latent infections. Further surveies with a larger cohort are necessary to corroborate our findings and to besides analyze the association of TLE with other herpesvirus such as HHV-6 and HHV-7.