Human cytomegalovirus infection in post left middle cerebral artery ischemic stroke patients

A Research Proposal

5-23-2013

Resident: John Ma, MD & PhD, PGY-2

Mentors: Jay Hammock, MD & Erika Erlandson, MD

Department of Physical Medicine & RehabilitationUniversity of Kentucky School of Medicine

Lexington, KY

Background:HCMV is a member of the viral family Herpesviridae. It is also known as human herpesvirus-5 (HHV-5). It is a DNA virus, infects humans in early in childhood transmitted by saliva, urine in daycare settings. After viremia, some individuals clear the viral infection; however, most of us experience latent infection throughout life. Like HSV, HCMV re-emerges when the host becomes immunocompromised.

infects lung, liver, spleen, kidney, glands, bladder, bone marrow, CNS etc.

Initial HCMV infection

HCMV viremia

Immunocompetent

Immunocompromised or decreasing immunity level such as HIV infection, immunosuppression, pregnancy, newborn, leukemia etc.

Latent infection, (months, years, life long)

CMV reactive infection

CMV infection has been reported in the following patient populations:

1. HIV/AIDS

2. Immunosuppressed organ transplant recipients

3. Newborns/infants with immature immune system

4. Pregnant women (Ma Z. et al, Chin. J of Clin & Exp Virol. 1992)

5. TB patients ( Ma Z et al, Acta of Qingdao Med. Coll. 1991)

6. Stroke : CMV infection is a risk factor for ischemic stroke

7. Leukemia or blood diseased patients

8. Congenital immunocompromised patients

S/S of CMV infection:

In immunocompetent people: No symptoms or flu like symptoms such as fatigue, malaise, runny nose, sore throat, low grade fever, muscle ache, or adenopathy

In immunocompromised people: - Visual impairment and blindness - Pneumonia - Diarrhea - Ulcers of the digestive tract, possibly causing bleeding - Hepatitis - Inflammation of the brain (encephalitis) - Behavioral changes - Seizures - Coma

• IN THE UNITED STATES, CMV INFECTS ~50-80% OF THE POPULATION BY 40 YEARS OF AGE. THE INFECTION RATE IS HIGHER WITH AGING. (WWW.CDC.GOV/CMV/CLINICAL/)

• HCMV infection is very common in the adult population.

• More than 90% of the population in developing countries is (+).

Cannon et al, Rev med virol, 2012, 20, 202-213

Cannon et al, Rev med virol, 2012, 20, 202-213

As a physiatrist, why do we care about HCMV infection???

In US, ~ 790,000 patients suffer strokes each year, making it the 3rd leading cause of death, after heart disease and cancer; 1st leading cause of disability

• > 50% stroke patients have latent HCMV infection.

• Stroke is a huge stress to the body, it leads to a compromised immune state, thus increasing the probability of latent HCMV re-activation

• HCMV infection is usually a missed diagnosis in the acute care hospital setting - As it is often latent, HCMV takes time to become re-active: * First, it inhibits host DNA and protein synthesis systems * Then, host DNA and protein synthesis systems are solely utilized for viral replication • HCMV would most likely become active in a rehab hospital setting because it takes about 7-10 days to become completely re-active

1. Chronic CMV infection is a risk factor of ischemic stroke, [Kis et al, New Microbiolgica, 2007, 30, 213-220] , [Huang et al, CNS Neuroscice & Therapeutic, 2012, 18, 457-460]

2. CMV and HSV infection are risk factors for future myocardial infarction and stroke [Ridker et al, Circulation , 1998, 98, 2796-2799]

Related Research

3. Significantly higher rate of cognitive decline with high levels of anti-CMV [Aiello et al, J. Am Geriatr Soc, 2006, 54, 1046-1054]

5. Chronic CMV infection is associated with prevalent frailty [Schmaltz et al, J. Am Geriatr Soc, 2005, 53, 747-754]

4. Chronic CMV infection is associated with ADLs impairment [Aiello et al, J. Gerontol. A Biol Sci Med Sci, 2008, 63(6), 610-618]

At present, there are no published data on HCMV prevalence in post-stroke patients.

In addition, there are no published studies that have examined the relationship between active CMV infection and rehab performance and/or hospital stay.

CMV in Stroke Rehab: Rationale and hypothesis

Lt MCA ischemic Stroke

Stress to immune system

Latent HCMVs become active

Subclinical/clinical symptoms such as fatigue, low grade fever, malaise,cognitive impairment, frailty and impairment on ADLs

Poor endurance, less motivated to anticipate in rehab program

Taking more time to reach maximal rehab goal

Prolonged rehab hospital stay and increased Medicare/Medicaid expense

• Aim 1: Study the prevalence of HCMV in post Lt MCA stroke pts

CMV in Stroke Rehab: Specific Aims

• Aim 2: Study the active HCMV infection in post-stroke pts

• Aim 3: Examine the relationship between active CMV infection and rehab performance (FIM score, PT/OT/SLP)• Aim 4: Comparison of hospitalization stay of CMV (+)/(-) patients

CMV in Stroke Rehab: Inclusion criteria

1. New onset 1st time Left MCA ischemic infarct at age 60-70

2. Cognitively being able to participate in rehab

3. Willing to participate in the research study

1. Known immunosuppression (e.g., organ transplants)2. Known HIV infection3. Known active PNA or UTI 4. Known long term use of steroid hormones5. Recent major surgery peri-stroke or post-OP stroke6. End-stage renal, liver, and/or lung disease7. Amputation8. Recurrent and/or chronic stroke9. Cancer patients with recent chemotherapy and/or XRT10.Very sick patients unable to participate rehab program11. Severe dementia/end stage of Alzheimer’s disease

CMV in Stroke Rehab: Exclusion Criteria

CMV in Stroke Rehab: Methodology

Age, gender, left MCA stroke (closed size) , similar co-morbidities such as DM, HTN, HLD, CKD, CAD, COPD, social-economic status, BMI matched

HCMV IgG in serum (ELISA)

HCMV IgG (-) HCMV IgG (+)

qPCR (-) qPCR (+)

Non

CM

V in

fect

ion

Act

ive

CM

V in

fect

ion

Lat

ent C

MV

infe

ctio

nComparison of FIM, PT/OT/SLP and hospital stay

ELISA: enzyme-linked immunosorbent assasyqPCR: quantitative polymerase chain reaction

Group Initial & d/c FIM ∆ FIM ∆ PT/OT/SLP Rehab days

HCMV IgG (-) /☻ ☻ ☻ fair/well

HCMV IgG (+), qPCR (-) /☺ ☺ ☺ fair/delay

HCMV IgG (+), qPCR (+) / longer .

CMV in Stroke Rehab: Possible Outcomes

FIM

sco

reP

T.O

T/S

LP

Viral copies by quantitative PCR

Possible relationship between FIM PT/OT/SLP performance and HCMV titer:

0 10 100 1,000 10,000 100,000

1. If our hypothesis is true that active CMV delays pts’ discharge, then we will further explore whether treatment of HCMV will improve rehab performance and/or decrease their hospital stay.

2. If our hypothesis is confirmed to be true, then a similar study design can be applied to TBI, SCI, and GRU patients.

3. Prevalence and effects of other chronic infections such as HSV, EBV and H. Pylori etc. can be evaluated in a rehab hospital setting.

CMV in Stroke Rehab: Future Directions

Acknowledgments

Mentor: Dr. Jay Hammock

Constant encouragement and help from: Dr. Nickerson, Dr. Schleenbacker, Dr. Ortiz, Dr. Stiles and Dr. Erlandson

Enthusiastic comments on the proposal from: Dr. Sawaki and Dr. Springer

The GREATEST study partners & friends : All the residents in this program, especially Dr. Thien Ngo and Dr. Dwan Perry.