Schizophrenia and Other Human Psychiatric Diseases

Challenges for 21st Century Researchers

Robert H Yolken, MDDirector, Stanley Neurovirology Laboratory

Ted and Vada Stanley Distinguished Professor of Pediatrics, Johns Hopkins School of Medicine, Baltimore Md.

E Fuller Torrey, MDMedical Director, Stanley Medical Research Institute, Bethesda Md

Faith Dickerson, PhD

Director of Psychology, Sheppard Pratt Health System, Baltimore Md.

SchizophreniaClinical and Epidemiological Features

Positive Symptoms Hallucinations, Delusions, Disordered Thinking

Negative Symptoms Withdrawal, Amotivation, Restricted Expressiveness

Impairment in Cognitive and Social Functioning Structural and Functional Brain Abnormalities Lifetime prevalence approximately 1% Peak onset of Symptoms in Young Adulthood Massive societal Consequences Worldwide Currently Available Medications

Symptomatic improvement High rate of side effects Do not affect overall disease process

Genetics Of Schizophrenia

• Increased Incidence in Biological First Degree Relatives • General Population 1%• First Degree Relatives 7-9%• Monozygotic Twins 30%

• Most individuals with schizophrenia do not have a first degree relative with this disease.

• Genetic factors have a large relative risk but a small risk in the overall population (5%)

• Intensive search for genes using molecular methods• Multiple (>30) chromosomal regions of linkage• Genetic polymorphisms of minor effect (OR~2) • No genes of major effect in different populations

Microbial Agents and SchizophreniaEpidemiological Findings

Specific Infectious Agent Perinatal Rubella (Brown et al, 2001; OR~3.5) Neonatal Enterovirus (Jones et al, 1998 OR~4) Maternal Herpesvirus (Buka 2001; OR~4)

Possible Infectious Exposure Seasonality of Birth (Torrey at al, 1998; OR~2) Urban Birth (Mortenson et at, 1999, OR~2.5) Exposures in Pregnancy (Brown et al, 2000; Torrey et al,

OR~3) Case Reports

HIV Herpes Simplex Virus Borrelia bergdorferii

Human Infectious DiseasesKnown Genetic Associations

Agent Gene FunctionHIV CCR5 Co-Receptor

EBV XLP T-Cell Activity

Hepatitis B Man BP Viral binding

Mycobacteria Il12; IFN R Phagocytosis

Salmonella Il12; IFN R Phagocytosis

H pylori HLA-DQ Immune Response

S mansoni GMCSF Phagocytosis

L donovani Cytokines Immune Function

P falciparum HgS,G6PD Oxygenation

Psychiatric DisordersAssociation with Viral Encephalitis

HSV-1

HIV

Influenza

Measles

EBV

Coxsackie

Mumps

Other

Unknown

0 10 20 30 40 50

Percentage (108 total cases)

Caroff et al, Psych Ann 31:193, 2001

Infections and PsychosisBacteria and Parasites

Bacteria Streptococcus

pyogenes Borrelia burgdorferi Treponema pallidum Ehrlichiae Mycoplasma

pneumoniae Bartonella henselae Salmonella typhii

Parasites Toxoplasma gondii Plasmodium falciparum Babesiae Taenia solium Leishmania donovani

Antecedents of Schizophrenia264 Cases/528 Controls

Fever in Pregnancy

Pregnancy Complications

Delivery Complications

Urban Birth

Developmental Delay

Family Cat

Family Dog

1 2 3 4

Odds Ratio (95% Conf)Scz Research 46:17-23, 2000

SchizophreniaWorking Hypotheses

Most cases of schizophrenia are the result of infections and other environmental insults occurring in genetically susceptible individuals before the onset of clinically apparent symptoms.

Distinct gene-environmental interactions may be operant in different populations.

The role of specific infectious agents can be defined by clinical trials of anti-microbial chemotherapy.

Identification of Infections in Schizophrenia Methods-Old and New

Analytic Methods Differential Display PCR Library screening Microarrays Two-dimensional electrophoresis Enzyme immunoassays

Samples for Analysis Brains collected by the Stanley Neuropathology

Consortium Cerebrospinal fluid and blood samples from individuals

with recent onset schizophrenia Blood samples from mothers of infants who developed

schizophrenia in adult life

Differential Display PCRBrain from Individual with Schizophrenia (S)

and Unaffected Control(U)

S S SU U UM M

Human Endogenous Retrovirus HERV-W

HIV

Endogenous RetrovirusesBorderland Between Viruses and Genes II

Dynamic Effects on Gene Function Promoter control of adjacent genes- PLA2; Placental Genes Functionality of viral proteins-Syncytin; ASCT1 Glutamate

transporter Interaction with infectious agents- Herpesviruses; Toxoplasma

Interaction with soluble mediators-Hormones; Cytokines Role in Human Disease

Diabetes- Superantigen activation Multiple Sclerosis- Glial cell function Autoimmune Arthritis- T cell activity

Endogenous RetrovirusesActivation and Transcription

DNA 5’LTR Viral Proteins 3’LTR

Microbe Hormone Mediator

Human RetrovirusesActivation by Herpesviruses

HerpesvirusRetrovirus Reverse Transcriptase Activity

Scz Ctr

DN

A

Endogenous Retroviral PCRCSFs:Schizophrenia and Controls

HERVw GTTCAGGGATAGCCCCCATCTATTTGGCCAGGCATTAGCCCAAGACTTGAGTCAATTCTCATACCTGGACACTCTTGTCCTTCAG C1 ---------------------------------------------------C--------------------------------- A1 ------------------------------A---------------------------------------------------TG- A2 ------------------------------A---------------------------------------------------TG- A3 ----------------------------------C----------------C--G----------------------------G- A4 -----------A----------------------------T----------C--G---------------------------TG- A5 -----A------------------------------------------------------------------------------- A6 ------------T------------CA---TA-------------------C--G---------------------------TG-

Herv-W

Reactivity to RetrovirusesSchizophrenia and Controls

Acu

te S

cz

Ch

ron

ic S

cz

Neu

ro C

trs

Un

aff

Ctr

s

.

Acu

te S

cz

Un

aff

Ctr

s

0

10

20

30

40

Perc

en

tag

e R

eacti

ve

CSF Blood

p<.001

Collaborative Perinatal StudyStudy Design

65,000 healthy mothers enrolled from 1957-1964 from 11 geographically diverse sites.

Mothers followed closely during pregnancy. Neurocognitive and developmental testing during

first 7 years of life. Primary outcomes cerebral palsy and mental retardation.

Serum samples obtained from mothers during pregnancy and infants at birth (cord).

Offspring identified with psychiatric diseases in 1990’s and matched to maternal and cord blood serum specimens.

Schizophrenia in Adult LifeInflammation During Fetal Development

IgG IgM IgA TNF IL1 IL2 IL6 IL80

1

2

3

4

5

6

7

8

9

Odds R

ati

o

*p<01

**

*

Schizophrenia in Adult LifeInfection During Fetal Development

CMVIgG

CMVIgM

RubIgG

RubIgM

ToxoIgG

ToxoIgM

HSV1IgG

HSV2IgG

HervW

0.00

1.20

2.40

3.60

4.80

6.00

Od

ds R

ati

o

National Children’s Study

Mandated by congress in 1999 Scheduled to start in 2004 Target enrollment of 100,000 births Follow-up of offspring for 30 years Specimen Collection and Storage Unanswered questions

Target diseases Number of sites Consent requirements System of medical care

HSV-1 Toxo CMV HSV-2 EBV HHV-660

65

70

75

80

Cog

nit

ive S

core

(R

BA

NS

Tota

l)

Infection and Cognitive FunctioningIndividuals with Schizophrenia (N=229)

Antibody Positive Antibody Negative

***

**p<.00001

*p<.009 Infectious Agent (IgG Antibodies)

Cognitive Functioning in Bipolar DisorderEffect of HSV-1 Infection

Immediate Memory

Delayed Memory

VisCon

Language

Attention

Total

70 75 80 85 90 95 100

RBANS Score

HSV-1 Neg HSV-1 Pos

<.01

Cognitive FunctioningSchizophrenia and Bipolar Disorder

MemoryTotal CognitiveMemoryTotal Cognitive60

70

80

90

100

Score

HSV-1 Infected HSV-1 Uninfected

Bipolar Disorder Schizophrenia

Acylovir-Mechanism of Action

Valacyclovir Clinical TrialIndividuals with Schizophrenia

Enrollment of 66 patients with stable schizophrenia on standard medication all given Valacyclovir 2 gm/day for 16 weeks

Evaluation by the positive and negative symptom score (PANSS)

Change in score correlated with viral antibody status at start of study HSV1/2 CMV Other herpesviruses

Response to ValacyclovirHSV-1 Antibody Status

2 4 8 12 16

Week of Valacyclovir

-10

0

10

20

Perc

en

tag

e I

mp

rovem

en

t

2 4 8 12 16

Week of Valacyclovir

-10

-5

0

5

10

15

20

Perc

en

tag

e I

mp

rovem

en

t

Positive Symptoms Total Symptoms

HSV-1 Seropositive HSV-1 Seronegative

Response to Valacyclovir by CMV Status

2 4 8 12 16-10

0

10

20

30

Per

cen

tag

e Im

pro

vem

ent

Positive Scale

2 4 8 12 16-10

0

10

20Negative Scale

2 4 8 12 16-10

0

10

20

Per

cen

tag

e Im

pro

vem

ent

General Scale

2 4 8 12 16-10

0

10

20Total Score

P<.0005P<.02

P<.006

CMV Seropositive CMV Seronegative

Prevalence of CytomegalovirusPopulations with Schizophrenia

0 10 20 30 40 50 60 70 80 90

Prevalence (%)

Cologne-Untreated

Cologne-Recently Treated

Cologne-Control

Heidelberg-Recently Treated

Heidelberg-Control

Baltimore-Chronic

New Therapies for SchizophreniaOngoing/Proposed Clinical Trials

Treatment Trials Valacyclovir Other medications for Cytomegalovirus Azithromycin trial for Toxoplasma gondii Antimicrobial aspects of Psychiatric Medications

Epidemiological Studies Additional Perinatal Cohorts Cohorts of Healthy Young Adults Cohorts of High-Risk Adolescents Intervention strategies for disease prevention

Infections and SchizophreniaConclusions

Recent onset schizophrenia is associated with: Increased transcription of HERV-W Increased levels of antibodies to CMV

Past infection with HSV-1 and Toxoplasma gondii are associated with cognitive impairment in individuals with stable schizophrenia.

Maternal exposure to infectious agents is associated with an increased rate of schizophrenia in the adult life of the offspring.

The administration of Valacyclovir can reduce symptoms in some individuals with stable schizophrenia.

Microbial Agents and Schizophrenia Acknowledgements

Johns Hopkins University Loraine Brando Vern Caruthers Inna Ruslanova Bogdana Krivogorsky

Stanley Program Michael Knable John Bartko

Sheppard Pratt Hospital Faith Dickerson John Boronow Catherine Stallings

Harvard University Steve Buka Ming Tsuang

University of Heidelberg Silke Bachmann Johannes Schroeder

Karolinska Institute Håkan Karlsson

University of Cologne F Markus Leweke