Issues Related to the Potential Transmission of Trypanosoma cruzi by Human Cells, Tissues and Cellular and Tissue-Based

Products (HCT/Ps)

Melissa A. Greenwald, M.D.Melissa A. Greenwald, M.D.Office of Cellular, Tissue and Gene Office of Cellular, Tissue and Gene

Therapies (OCTGT); CBERTherapies (OCTGT); CBERBlood Products Advisory CommitteeBlood Products Advisory Committee

26 April 200726 April 2007

Overview

• Question for the CommitteeQuestion for the Committee• BackgroundBackground

• About HCT/PsAbout HCT/Ps• About Chagas’ diseaseAbout Chagas’ disease

• Results of Literature ReviewResults of Literature Review• Final CommentsFinal Comments

Question for Committee

• Please comment on the current Please comment on the current scientific data as it relates to the scientific data as it relates to the potential for transmission of Chagas’ potential for transmission of Chagas’ disease by HCT/Ps.disease by HCT/Ps.

Background

What is an HCT/P?What is an HCT/P?

• HCT/Ps are regulated by OCTGTHCT/Ps are regulated by OCTGT• HCT/Ps encompass a wide variety of HCT/Ps encompass a wide variety of

productsproducts• 21 CFR 1217.3(d) defines HCT/Ps as 21 CFR 1217.3(d) defines HCT/Ps as

articles containing or consisting of human articles containing or consisting of human cells or tissues that are intended for cells or tissues that are intended for implantation, transplantation, infusion, or implantation, transplantation, infusion, or transfer into a human recipient transfer into a human recipient

Examples of HCT/Ps

• Musculoskeletal tissuesMusculoskeletal tissues• Skin Skin • Dura Mater Dura Mater • Cardiovascular tissues Cardiovascular tissues • Ocular tissues Ocular tissues • Reproductive cells and Reproductive cells and

tissuestissues

• Hematopoietic Hematopoietic stem/progenitor cells stem/progenitor cells derived from peripheral derived from peripheral and cord blood and cord blood

• Other cellular therapiesOther cellular therapies• Gene therapies Gene therapies • Tissue/device and other Tissue/device and other

combination productscombination products

Not HCT/Ps

• Vascularized human organs for Vascularized human organs for transplantation (HRSA oversight);transplantation (HRSA oversight);

• Whole blood or blood components or Whole blood or blood components or blood derivative products;blood derivative products;

• Secreted or extracted human Secreted or extracted human products, such as milk, collagen, and products, such as milk, collagen, and cell factorscell factors

Not HCT/Ps (continued…)• Minimally manipulated bone marrow for Minimally manipulated bone marrow for

homologous use and not combined homologous use and not combined with a drug or a device;with a drug or a device;

• Ancillary products used in the Ancillary products used in the manufacture of HCT/P;manufacture of HCT/P;

• Cells, tissues, and organs derived from Cells, tissues, and organs derived from animals other than humans; andanimals other than humans; and

• In vitro diagnostic productsIn vitro diagnostic products

HCT/P Donor Screening & Testing

• Donor screening Donor screening • medical history interview, medical history interview, • physical assessment/examination, and physical assessment/examination, and • medical record review medical record review

• Donor testing Donor testing • FDA-licensed, cleared or approved donor FDA-licensed, cleared or approved donor

screening testsscreening tests• Specifically labeled for cadaveric donors, Specifically labeled for cadaveric donors,

if applicable and available if applicable and available

RCDADs—diseases for which all HCT/P donors are currently screened and/or tested

• Human immunodeficiency virus (HIV), Human immunodeficiency virus (HIV), types 1 and 2; types 1 and 2;

• Hepatitis B virus (HBV);Hepatitis B virus (HBV);• Hepatitis C virus (HCV);Hepatitis C virus (HCV);• Human transmissible spongiform Human transmissible spongiform

encephalopathy (TSE), including encephalopathy (TSE), including Creutzfeldt-Jakob disease (CJD); and Creutzfeldt-Jakob disease (CJD); and

• Treponema pallidumTreponema pallidum (syphilis) (syphilis) RCDADs are Relevant Communicable Disease Agents or Diseases

“New” RCDADs• We have recently issued (final) guidance We have recently issued (final) guidance

describing the following to be RCDADs for all describing the following to be RCDADs for all HCT/Ps HCT/Ps • West Nile VirusWest Nile Virus• SepsisSepsis• Vaccinia (the virus used in smallpox Vaccinia (the virus used in smallpox

vaccine)vaccine) • Today’s discussion will focus on the current Today’s discussion will focus on the current

scientific data as it relates to the potential for scientific data as it relates to the potential for transmission of Chagas’ disease by HCT/Ps transmission of Chagas’ disease by HCT/Ps and thus, the possible need to test HCT/P and thus, the possible need to test HCT/P donors for donors for T. cruziT. cruzi

Background, continued

Chagas’ diseaseChagas’ disease

http://www.canr.msu.edu/vanburen/fbenny.htm

Transmission of T. cruzi• In addition to transmission by a vector, In addition to transmission by a vector,

published literature indicates the following published literature indicates the following other means of other means of T. cruziT. cruzi transmission transmission

• Vertical (congenitally/mother to infant) Vertical (congenitally/mother to infant) • Oral (breast milk or contaminated food) Oral (breast milk or contaminated food) • Entrance via conjunctiva from hand Entrance via conjunctiva from hand

contaminationcontamination• Blood transfusionBlood transfusion• Organ transplantationOrgan transplantation

T. Cruzi lifecycle in humans

• Trypomastigotes in Trypomastigotes in bloodblood

• Invade tissue/cellInvade tissue/cell• Convert to Convert to

amastigote form and amastigote form and replicatereplicate

• Trypomastigotes Trypomastigotes released into released into bloodstream to bloodstream to circulate or invade circulate or invade other host cellsother host cells

Tulane.edu

Tissue Transmission of T. cruzi• No reports of tissue transmissionNo reports of tissue transmission• Association between the tissue Association between the tissue

transplant and the development of transplant and the development of symptoms may not be recognized symptoms may not be recognized • long time between exposure and long time between exposure and

symptom development in symptom development in immunocompetent individualsimmunocompetent individuals

• acute phase usually asymptomaticacute phase usually asymptomatic• chronic (indeterminate) phase chronic (indeterminate) phase

asymptomaticasymptomatic

Tissue Transmission of T. cruzi (continued…)

• May be difficult to recognize a tissue May be difficult to recognize a tissue transplant-transmitted infection in an endemic transplant-transmitted infection in an endemic area where there is vector exposure area where there is vector exposure

• Tissue allografts generally undergo some Tissue allografts generally undergo some processing—some methods may remove or processing—some methods may remove or inactivate inactivate T. cruziT. cruzi

• Some cellular products are cryopreserved; Some cellular products are cryopreserved; some tissues are frozen—parasite may some tissues are frozen—parasite may survive 2-3 weeks at refrigerator or freezer survive 2-3 weeks at refrigerator or freezer temperatures, survival beyond that time temperatures, survival beyond that time period is unknown period is unknown

Tissue distribution of T. cruzi in infected individuals

• Information is scant Information is scant • Acute phaseAcute phase

• Parasites found in skin lesions at site Parasites found in skin lesions at site of transmissionof transmission

• Spread through the bloodstream Spread through the bloodstream • Lodge in various tissues, particularly Lodge in various tissues, particularly

skeletal muscle skeletal muscle

Tissue Distribution of T. cruzi in infected individuals (continued…)

• Chronic asymptomatic phaseChronic asymptomatic phase• muscle (especially cardiac muscle)muscle (especially cardiac muscle)• nerve nerve • digestive tract digestive tract

• Little investigation of distribution within Little investigation of distribution within otherother tissues during this phase (tendency to look at tissues during this phase (tendency to look at tissues that have known clinical tissues that have known clinical manifestations)manifestations)

• Parasites have been demonstrated in the Parasites have been demonstrated in the affected tissues of individuals who die with affected tissues of individuals who die with cardiomyopathy, megaesophagus, or cardiomyopathy, megaesophagus, or megacolonmegacolon

Review of T. cruzi literature provided to the committee

http://www.ctegd.uga.edu/misc_pages/parasites.html

Mouse Studies• Mice inoculated with Mice inoculated with T. cruziT. cruzi

demonstrated parasites in skeletal demonstrated parasites in skeletal muscle, heart, bladder, peripheral muscle, heart, bladder, peripheral nerve, liver, spleen, adrenal gland, nerve, liver, spleen, adrenal gland, brain, and adipose tissuebrain, and adipose tissue• Parasite load decreased 100-fold over 10 Parasite load decreased 100-fold over 10

months, still demonstrated visible months, still demonstrated visible parasites in skeletal muscle and bladderparasites in skeletal muscle and bladder

• Mice subcutaneously inoculated with Mice subcutaneously inoculated with T. T. cruzicruzi demonstrated PCR positivity for demonstrated PCR positivity for T. T. cruzicruzi DNA in ocular tissue and DNA in ocular tissue and surrounding structuressurrounding structures

Mouse Studies (continued…)

• Experimentally infected mice demonstrated Experimentally infected mice demonstrated pseudocysts filled with amastigotes in <1% of pseudocysts filled with amastigotes in <1% of evaluated tissue sections; but IHC methods evaluated tissue sections; but IHC methods demonstrated demonstrated T. cruziT. cruzi antigens in 11% of antigens in 11% of inflammatory infiltrates (visualization of inflammatory infiltrates (visualization of amastigotes may be insensitive)amastigotes may be insensitive)

• Experimentally infected mice demonstrated Experimentally infected mice demonstrated T. T. cruzicruzi in sternum chondroblasts, osteoblasts, in sternum chondroblasts, osteoblasts, macrophages and fibroblasts (osteocyte and macrophages and fibroblasts (osteocyte and chondrocyte invasion was rare)chondrocyte invasion was rare)

Human Placenta Study

• Human placentas (collected post-Human placentas (collected post-partum) were perfused and inoculated partum) were perfused and inoculated with a bolus containing with a bolus containing T. cruziT. cruzi trypomastigotestrypomastigotes

• Specimens collected immediately Specimens collected immediately following perfusion; after 24 and 48 following perfusion; after 24 and 48 hours of incubationhours of incubation• T. cruziT. cruzi DNA was identified in cells DNA was identified in cells

within all postinoculation placental within all postinoculation placental tissue specimenstissue specimens

Clinical data

• Individuals with chronic Chagas’ Individuals with chronic Chagas’ disease who underwent disease who underwent endomyocardial biopsy demonstratedendomyocardial biopsy demonstrated• T. cruziT. cruzi antigenic deposits by antigenic deposits by

immunohistochemical techniquesimmunohistochemical techniques• T. cruziT. cruzi DNA by PCR DNA by PCR• Histopathology evaluation—necrosis, Histopathology evaluation—necrosis,

inflammatory infiltrates, and fibrosisinflammatory infiltrates, and fibrosis

Clinical Data (continued…)

• Study demonstrated a correlation Study demonstrated a correlation between the presence of between the presence of T. cruziT. cruzi antigen and the severity of myocardial antigen and the severity of myocardial inflammatory processinflammatory process

• T. cruziT. cruzi DNA by PCR has been DNA by PCR has been demonstrated in esophageal tissues of demonstrated in esophageal tissues of persons who died of esophageal persons who died of esophageal Chagas’ diseaseChagas’ disease

Final Comments

Science Daily.com Credits:

WHO/TDR/Stammers

How do HCT/Ps transmit infection?

• Infectious disease transmission by Infectious disease transmission by HCT/Ps is complex—much is unknown HCT/Ps is complex—much is unknown

• In cases of known transmission of other In cases of known transmission of other infectious disease agents (e.g., HIV, infectious disease agents (e.g., HIV, HBV, and HCV), it has been difficult to HBV, and HCV), it has been difficult to determine whether transmission occurs determine whether transmission occurs because ofbecause of• agent in the tissue, or agent in the tissue, or • agent in blood that is in the tissueagent in blood that is in the tissue

How do HCT/Ps transmit infection? (continued…)

• Infectious dose of Infectious dose of T. cruziT. cruzi is not clearly is not clearly defined in the literature, generally defined in the literature, generally believed to be lowbelieved to be low

• What activates the organism to mobilize What activates the organism to mobilize from the intracellular amastigote stage from the intracellular amastigote stage into bloodborne trypomastigotes is also into bloodborne trypomastigotes is also unknown, but has been demonstrated to unknown, but has been demonstrated to occur in persons who were infected via occur in persons who were infected via organ transplantationorgan transplantation

Summary

• T. cruziT. cruzi is found in blood and various is found in blood and various tissuestissues

• Much is unknown about potential Much is unknown about potential transmission from tissue allograftstransmission from tissue allografts

• Necessary to make public health Necessary to make public health decisions based on best available decisions based on best available informationinformation

References

• Anez N, et al. Myocardial Parasite Anez N, et al. Myocardial Parasite Persistence in Chronic Chagasic Patients. Persistence in Chronic Chagasic Patients. Am J Trop Med, 1999;60(5):726-732Am J Trop Med, 1999;60(5):726-732

• Bellotti, et al. In vivo detection of Bellotti, et al. In vivo detection of Trypanosoma cruziTrypanosoma cruzi antigens in hearts of antigens in hearts of patients with chronic Chagas’ heart disease. patients with chronic Chagas’ heart disease. American Heart Journal, 1996 American Heart Journal, 1996 Feb;131(2):301-307Feb;131(2):301-307

• Buckner FS, et al. Detection of Live Buckner FS, et al. Detection of Live Trypanosoma cruziTrypanosoma cruzi of Infected Mice by Using of Infected Mice by Using Histochemical Stain for β-Galactosidase. Histochemical Stain for β-Galactosidase. Infection and Immunity, 1999 Infection and Immunity, 1999 Jan;67(1):403-409Jan;67(1):403-409

References, cont.

• Herrera L, et al. Cornea as a tissue reservoir Herrera L, et al. Cornea as a tissue reservoir of of Trypanosoma cruziTrypanosoma cruzi. Parasitol Res, 2006 . Parasitol Res, 2006 NovNov

• Morocoima A, et al. Morocoima A, et al. Trypanosoma cruziTrypanosoma cruzi: : experimental parasitism of bone and experimental parasitism of bone and cartilage. Parasitol Res, 2006;99:663-668cartilage. Parasitol Res, 2006;99:663-668

• Shippey SH, et al. Use of the placental Shippey SH, et al. Use of the placental perfusion model to evaluate transplacental perfusion model to evaluate transplacental passage of passage of Trypanosoma cruziTrypanosoma cruzi. Am J Ob Gyn, . Am J Ob Gyn, 2005;192:586-5912005;192:586-591

References, cont.

• Vago AR, et al. PCR detection of Vago AR, et al. PCR detection of Trypanosoma cruziTrypanosoma cruzi in oesophageal tissues of in oesophageal tissues of patients with chronic digestive Chagas’ patients with chronic digestive Chagas’ disease. Lancet, 1996 Sep;348:891-892disease. Lancet, 1996 Sep;348:891-892

• Younes-Chennoufi AB, et al. Persistence of Younes-Chennoufi AB, et al. Persistence of Trypanosoma cruziTrypanosoma cruzi in the inflammatory in the inflammatory lesions of chronically infected mice. lesions of chronically infected mice. Transactions of the Royal Society of Tropical Transactions of the Royal Society of Tropical Medicine and Hygiene, 1988;82:77-83Medicine and Hygiene, 1988;82:77-83