Infections and Psychiatric DiseasesLecture Outline

Clinical and Epidemiologic Features of Schizophrenia and Bipolar Disorder

Biology of Endogenous Retroviruses Role of Herpesviruses in Retroviral

Transcription Clinical Epidemiology of Herpesvirus

Infections and Psychiatric Diseases Clinical Trials of Antimicrobial Agents

Schizophrenia and the Clinical LaboratoryOpportunities and Challenges

OpportunitiesCommon Disease (1% of American Population)Availability of more easily tolerated medications

ChallengesRudimentary knowledge of disease pathogenesisNo relevant animal models or cell linesNo laboratory testsMinimal prediction of response to medication

Schizophrenia and Bipolar DisorderClinical Features

Schizophrenia Positive Symptoms

Hallucinations, Delusions, Disordered Thinking Negative Symptoms

Withdrawal, Amotivation, Restricted Expressiveness Impairment in Cognitive and Social Functioning Lifetime prevalence ~ 1% worldwide

Bipolar Disorder Mania Depression Variable degree of positive and negative symptoms Variable degree of cognitive impairment Lifetime prevalence ~0.5% worldwide

A Beautiful MindHollywood or Reality

A Beautiful MindHollywood vs Reality?

Reality Onset of schizophrenia without clear cause Attractiveness of delusions Role of medication Disease “burn out” at later age

Hollywood Delusions coinciding with creativity Shock therapy used at “high class” hospital Family support

Schizophrenia and Bipolar DisorderBiological and Epidemiological Features

Lifelong illness with peak onset in early adulthood. Range of structural and functional brain abnormalities

visible on fMRI and PET scans. Abnormal expression of brain receptors

Dopamine Glutamate

Massive social and economic consequences Available medications

Control symptoms in many patients Have a high rate of side effects Do not appreciably alter the course of disease

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) Fever in Pregnancy (Torrey et al 2000, OR~3) Pre-eclampsia ( Dalman et al, 1999, OR~2.5)

Case Reports HIV Herpes Simplex Virus 1/2 Toxoplasma gondii

Genetics Of Schizophrenia and Bipolar Disorder

• 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 chromosomal regions of linkage• Single nucleotide polymorphisms of minor effect in selected

populations (OR~2) • No genes of major effect in different populations

Complex Human DiseasesBeyond Koch and Mendel

Mendel-Human traits are determined by individual

genes which function independently of other genes and of environmental

influences

Koch-Many human diseases are caused by microbes which exert

their effect independently of other microbes, environmental factors and

genes

Microbial Agents and Human Disease Koch’s Postulates

Principles Specific infectious agents cause clearly delineated

disease states The diseases cannot exist without the specific agent Etiologic agents cause disease in animal models

Limitations Shared pathways of response to infection Genetic determinants of response Individual variation in response to infection Limited animal models of complex human diseases

Complex Human DiseasesBeyond Koch’s Postulates

Most common human diseases are caused by the interaction of environmental insults and susceptibility genes.

Many of the susceptibility genes are diverse determinants of human response to environmental factors to infection.

Informative laboratory methods for complex disorders have to address both genetic and environmental factors.

Prevention or treatment of the infections may result in the effective treatment of complex disorders: Helicobacter-Peptic Ulcer HPV-Genital Cancer Chlamydia-Cardiac Disease?

Etiology of Complex Human DiseasesRelative vs. Attributable Risk

Relative Risk-Chance of an individual with an exposure acquiring a disease relative to the general population

Population Attributable Risk-Percentage of the population with a disease which can be attributed to a specific factor

Diseases of single or limited etiologies-High relative and attributable risks CFTR gene-Cystic Fibrosis HIV-Acquired Immunodeficiency Syndrome

Complex Human Diseases Factors with high relative risk may have low attributable risks if exposures are rare Apoliprotein genes-Alzheimer’s Disease Maternal alcohol-Fetal malformations M tuberculosis-Lung Disease

Epidemiology of SchizophreniaRelative vs. Attributable Risk

Factor Relative Risk

Affected Father 7.2

Affected Mother 9.3

Affected Sibling 7.0

Urban Birth 2.4

Winter Birth 1.1

No Factor 1.0

Mortenson et al, NEJM 340:603, 1999

Epidemiology of SchizophreniaRelative vs. Attributable Risk

Factor Relative Risk % Cases In Population

Affected Father 7.2 1.2%

Affected Mother 9.3 2.4%

(No affected parent) 88.8%

Affected Sibling 7.0 2.2%

(No affected sibling) 97.8%

Urban Birth 2.4 32.9%

Winter Birth 1.1 25%

Mortenson et al, NEJM 340:603, 1999

Epidemiology of SchizophreniaRelative vs. Attributable Risk

Risk Factor Population Attributable Risk

Affected Parent 3.8%

Affected Sibling 1.9%

Affected Parent or Sibling 5.5%

Place of Birth 34.6%

Season of Birth 10.5%

Place and Season of Birth 41.4%

All Variables 46.6%

Mortenson et al, NEJM 340:603, 1999

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.

Interactions do not follow Koch’s postulates. 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 fluids (CSF’s) 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

Integrated Genomic Elements with Homology to Retroviruses Arising from Germ Line Integration of infectious viruses during evolution All Primates Old World Monkeys Apes Humans Individuals

Endogenous RetrovirusesBorderland Between Viruses and Genes II

Dynamic Effects on Gene Function Promoter control of adjacent genes- PLA2; Placental Genes Interaction with infectious agents- Herpesviruses, Toxoplasma Interaction with soluble mediators-Hormones; Cytokines

Functionality of viral proteins-Syncytin; amino acid transporters Role in Human Disease

Diabetes- Superantigen activation Multiple Sclerosis- Glial cell function Autoimmune Arthritis- T cell activity Pre-Eclampsia- Aberrant Fusion of Trophoblasts

Endogenous RetrovirusesActivation and Transcription

DNA 5’LTR Viral Proteins 3’LTR

Microbe Hormone Mediator

Endogenous RetrovirusesBorderland Between Viruses and Genes

Integrated Genomic Elements with Homology to Retroviruses Arising from Germ Line Integration of infectious viruses during evolution All Primates Old World Monkeys Apes Humans Individuals

Herv-W

K113

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

Herv-W EnvelopeChromosomal Distribution

Herv-W and Amino Acid TransportersLavillette et al, J Virol Jul;76(13):6442-52.

ASCT1 HERV-W ReceptorBrains of Cases and Controls

Neuron Inter-Neuron White Matter0

1

2

3

4

5

Con

ten

trati

on

of

AS

CT1 R

ece

pto

r

Schizophrenia Bipolar Disorder Control

Cingulate Gyrus

P<.005

P<.009

P<.02

Human Endogenous RetrovirusesActivation by HSV-1Perron et al J Gen Virol. 1993 Jan;74 ( Pt 1):65-72.

HSV-1Retrovirus Reverse Transcriptase Activity

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

65

70

75

80

Cog

nit

ive S

core

(R

BA

NS

Tota

l)

Cognitive Functioning and Antibodies to Infectious AgentsIndividuals with Schizophrenia (N=229)

Antibody Positive Antibody Negative

***

**p<.00001

*p<.009 Infectious Agent (IgG Antibodies)

Cognitive Deficits In Individuals with SchizophreniaRelationship with Antibodies to HSV-1

Immediate Memory

Concentration

Language

Attention

Delayed Memory

RBANS Total

50 55 60 65 70 75 80 85 90

Score(Mean+/-95% Confidence)

HSV-1 Pos

N=101

HSV-1 Neg

N=128

******

******

****

**

**

*** p<.0001*** p<.0001**p<.001**p<.001* p<.009* p<.009

Cognitive FunctioningAssociation with HSV-1 Serostatus

Schizophrenia Bipolar Disorder Control60

65

70

75

80

85

90

95

100

RB

AN

S T

ota

l S

core

HSV-1 Seropositive HSV-1 Seronegative

N=229Pr=44.1%

N=117Pr=41.9%

N=67Pr=41.8%

Cognitive Function in Schizophrenia and Bipolar DisorderHSV-1 Antibodies and Quintile of Total Score

<20th 20-40 40-60 60-80 >80th

Percentile- Total Cognitive Score

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

Pro

port

ion

HS

V-1

Sero

reacti

ve Schizophrenia

N=229

Bipolar Disorder

N=117

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.

Unselected offspring evaluated for abnormalities of pregnancy, birth, and child development.

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

Effect of HERV-K and HSV-1 on Eclampsia and Mental Illness

Herv-K HSV-1HERV-K/HSV-1 . Herv-K HSV-1HERV-K/HSV-10

1

2

3

4

5

6

7

8

9

10

Od

ds R

ati

o

Unadjusted Adjusted for

Race, SES

Eclampsia Mental Illness

Effect of Maternal HSV-2 on Pregnancy and Child Development

Age 7-8 Perinatal

Abnormal Speech

Low IQ Abnormal Vision

AnyComplication

Fetal Deaths0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

Od

ds R

ati

o

Unadjusted Adjusted for

Race, SES

Valacyclovir Clinical TrialIndividuals with Schizophrenia

Enrollment of 66 patients with stable schizophrenia on standard medication 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

Prevalence (%)

Cologne-Untreated

Cologne-Recent Onset- Treated

Cologne-Control

Heidelberg-Recent Onset- Treated

Heidelberg-Control

Baltimore-Stable Treated

Baltimore-Control

Effect of Valacyclovir on SchizophreniaPossible Explanations

Statistical artifact ? p<.0005 with covariance for multiple factors

Placebo effect? Improvement only in CMV seropositive subjects Improvement persists throughout treatment

Non-viral effect of valacyclovir/acyclovir? Effect only in CMV seropositive individuals

The replication of CMV contributes to the symptoms of schizophrenia in some individuals Possible role of an antigenically related herpesvirus?

Valacyclovir Treatment of Schizophrenia-Planned Trials

Placebo-control trials using encapsulated valacyclovir and placebo Stable patients with schizophrenia Recent onset patients with schizophrenia Patients with bipolar disorder High-risk individuals with prodromal symptoms

Study supported by the Stanley Medical Research Institute, without support from the pharmaceutical industry.

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 is associated with cognitive impairment in individuals with stable schizophrenia and bipolar disorder, but not in unaffected controls.

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

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

The continued evaluation of the role of the prevention and treatment of infection in the management of psychiatric diseases remains a high priority.

Microbial Agents and Schizophrenia Acknowledgements

Johns Hopkins University Loraine Brando Frances Yee Vern Caruthers Inna Ruslanova Bogdana Krivogorsky

Stanley Medical Research Institute Michael Knable Maree Webster

Sheppard Pratt Hospital 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