Transcript Infusion of Culture Positive Stem Cell Products

Infusion of Culture Positive
Stem Cell Products
FDA Liaison Meeting
June 16, 2006
D. A. Gastineau
Mayo College of Medicine
Overview
• Background-historical perspective
• Questions to be addressed
• Specific Experience at Mayo
• ISCT Survey
• Changes to practice of respondents
• influence on sterility results
• Closed Systems
• Conclusions
Background
• Human bone marrow and PBPC transplant
products have traditionally been sampled
for bacterial contamination
• A small percentage of these products have
positive cultures
• Known culture positive products have
commonly been infused
• However, strict interpretation of the new
GTP regulations prohibit this practice
Experience at Mayo
• 7233 HPC products collected from
January 1998 through March 2006
• 2118 transplants performed
• Review of medical records for
evidence of adverse reactions,
toxicity and post-transplant blood
cultures for the 69 patients (3% of
total) who received positive products.
Collection and Transplant Activity
Total Collections
7233
Auto BM
131
Allo BM
127
PBPC
6838
DLI
137
Transplants Auto
1764
Transplants Allo
354
Sterility Testing at Mayo
• Before 3/04 1 ml was injected in an
isolator tube and incubated for 28
days
• After 3/04 1 ml was injected in peds
Bactec bottle and incubated for 5
days.
• Samples were taken from the product
upon arrival in the laboratory and
after all processing before freezing
Frequency of Positive Products
Total Products
Apheresis
Bone
Marrow
All Collections
7233
6975
258
Culture positive (%)
119 (1.6%)
111 (1.6%)
8 (3.1%)
Excluding Culture
Positive Donors
7201
6944
257
Culture positive (%)
87 (1.2%)
80 (1.2%)
7 (2.7%)
Sources of Bacteria in Product
Cultures
• Donor (patient)
• Introduced during collection
• Introduced during processing
• Introduced during sampling
• Introduction during thawing process
• Did not examine
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or
B
Pr
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Pr
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% Culture Positive
Post Thaw Culture Concordance Rate
(n=67)
100
75
50
25
0
Donor/Patient as the Source of
contamination
Preprocess
sample=A
Positive
Products
Postprocess
sample=B
Total
Sample A
Products
from Culture
Positive
Patients
119
43
32 (27%)
2 (5%)
Sample A&B
29
21 (72%)
Sample B
47
9 (19%)
Culture Positive Products
• When two cultures are positive (the
“A” and “B” cultures), 21 of 29 or
72% of patients had concomitant
bacteremias documented by blood
culture.
• The PATIENT is a major source of
bacteria
Organisms from HPCs
Organisms
Coagulase negative Staphylococci
Isolates
Infused
73
57
Staphylococcus aureus
8
5
Corynebacterium sp.
7
5
Enterococcus faecalis
6
6
Acinetobacter sp.
3
1
Moraxella sp
2
0
Micrococcus sp.
3
2
Gram negative bacillus
3
3
Stenotrophomonas maltophilia
3
Organisms from HPCs
Organisms
Isolates
Infused
Pseudomonas aeruginosa
2
2
Acid fast bacilli
1
1
Escherechia coli
1
1
Enterobacter cloacae
1
1
Filamentus fungus
1
1
Propionibacterium sp.
1
1
Ralstonia pickettii
1
1
Staphylococcus haemolyticus
1
1
Staphylococcus lugdunensis
1
1
Group A streptococcus
1
1
Chaetomium sp.
1
Chryseobacterium sp
1
Clostridium perfringens
1
Methylobacterium sp.
1
Pseudomonas fluorescens/putida
1
Infusion of Positive Products
Total Number of
95
Patients with positive
products collected
Total Positive
119
Products collected
Total Patients
Receiving Positive
Products
Total Positive
Products Infused
69
88
Figure 2
100 Day Survival Following Infusion of Culture Positive Products
Percent Surviving
100
75
p = 0.419
Controls n = 2046
50
Culture Pos n = 69
25
0
0
10 20 30 40 50 60 70 80 90 100
Days
Conclusion
• Clinical Significance of infusion of
positive products
• Minimal acute toxicity or adverse
reactions
• Equivalent short-term and longterm survival
Survey Sponsored by ISCT
• Goals
• Obtain general information about
the current practice of
hematopoietic stem cell therapy
• Obtain preliminary information
concerning experience with safety
of culture-positive products
Overall Summary: 177 Reporting Institutions
Institution/Organizational Unit
140
119
120
100
80
60
40
20
29
26
3
0
Stand alone
Stand alone
Clinical transplant
collection facility processing facility
program
Combined
clinical,
collection,
processing facility
Survey Question: Does your institution have a
policy for handling culture-positive products?
9%
1%
Yes
No
Not sure
90%
Policies encompass these elements
Evaluation of the patient for
current antibiotic use and/or
use of prophylactic
antibiotics if product is used,
120
Informed consent of the
patient if product is used, 76
Infusion of the product w ith
positive culture , 118
Notification of the patient's
physician, 150
Involvement of the cell
therapy lab director, 143
Investigation of the positive
culture, 146
0
20
40
60
80
100
120
140
160
Types of Products (92 Respondents)
70000
60000
65366
50000 48372
40000
30000
20000
12547
10000
5005
0
Products
R
D
SC
PB
LI
LI
/D
SC
/D
PB
SC
PB
ed
at
el
o
ut
l
ta
To
U
R
A
Frequency of Positive Products
40000
36736
35000
30000
26296
- Cult Infused
+ Cult Infused
- Products
+ Products
25000
20000
15000
10000
5000
464
512
1.7%
1.4%
0
Infusion of positive products:
Institutional Responses
Has your institution ever infused or released for infusion a PBPC or
DLI product:
117
Yes
(67%)
64
That was known to be culturepositive before the infusion?
53
No
71
That became culture-positive after
the infusion?
5
Not Sure
18
0
20
40
60
80
100
120
140
Test Methods for Sterility
15%
BacT/Alert
37%
8%
Bactec
CFR/USP compliant
method
Other (Please specify)
40%
Distribution of Organisms Found
15%
2%
1%
6%
1%
46%
0%
1%
2%
0% 3%
1%
2%
12%
0% 4%
5%
Coagulase-negative staphylococcus
Staphylococcus aureus
Streptococcus species
Acinetobacter
Propionobacterium species
Corynebacterium
Micrococcus
Klebsiella species
Clostridium species
E. coli
Enterobacter
Stenotrophomonas maltophilia
Pseudomonas aeruginosa
Other gram negative rods
Candida species
Aspergillus species
Other
Association With Donor
Bacteremia
• 32% of positive cultures reported to
be associated with a positive culture
in the patient/donor within 5 days
before or after collection
Deaths Associated with Infusions
• Of 91 respondents
• 4 reported deaths likely related to
infusion
• 0 were felt to be due to microbial
contamination
• 1 response was excluded as it
reported 6 deaths but fewer than
100 infusions and was otherwise
very incomplete
ISCT Survey Respondents
Collection/processing changes introduced
to reduce contamination
• Clean room facilities introduced
• No effect
• Second cultures sent from frozen samples
• If negative, presumed to be false
positive
• All products since April 2003 have been in cGMP
facility, Grade A critical area, Grade B background
• No change in rates
• Validated blood culture process, discontinued use
of multi-use heparin vials
• Reduction from 4% to 1.9% between
2003 and 2005
ISCT Survey Respondents
Collection/processing changes introduced
to reduce contamination
• Implemented new cleaning of BSCs, “robust”
changeover procedures, increased BSC
preventive maintenance
• Process in BSC, clean with 70% sterile alcohol between each product
•
•
•
•
•
•
processed.
More strict gowning procedures, including use of sterile gloves.
Perform EM daily
Innoculate cultures for microbial testing in BSC in cell processing
lab and then transport to microbiology.
GMP/GTP training performed for all staff in Cell Processing and
Microbiology departments including using sterile technique.
Rearrangement of microbiology laboratory to accommodate
microbial cultures for cellular products and to incubate all of these
cultures in an isolated incubator.
Perform tracking and trending of all positive cultures.
• No effect on rates seen
ISCT Survey Respondents
Collection/processing changes introduced
to reduce contamination
• We used to culture every product immediately
after collection and after processing. We reduced
cost of culture and removed an unnecessary step.
We have implemented additional training
regarding the line connections to reduce possible
contamination. We had our infection control
department observe all steps of the process to
make suggestions to improve our handling and
reduce possible contamination in the laboratory.
Overall our number of positive cultures has
dropped from approximately 5.5% to less than 4%.
In 2005 we did not have any contaminated
products. (?)
Changes Introduced to Reduce Infection Risk and
Effects
• Introduction of sterile sleeves
• Sterile gloves
• No longer perform separate fungus
culture. Reduced the number of
positive cultures related to
contamination by reference lab. (no
numbers given)
What is a Closed System?
• Closed
• “ . . . an isolated system having no
•
•
interaction with an environment.”
Dictionary of Cybernetics and Systems
To be completely closed a product
should not be exposed to the external
environment from beginning to end of
the processing.
Is this feasible?
• Collection: Venipuncture
• Sterile docking—adding reagents
• Sampling
• Infusion
What is a Closed System?
• What would be a closed system?
• A container with all necessary
additives and vessels for
processing attached to an
original collection container
• Final vessel disconnected from
original set of containers
• BUT: How to sample in
process (also separate
sample bags?)
What is a Semi-closed System?
• Definition varies widely
• Generally refers to processes
which have been adapted to bags
from “open” processes such as
ficoll-hypaque
• Tsang, Transfusion, 2001
What is a Functionally-closed
System?
• Functionally-closed systems
• Varies as well
• Processing cord blood with bags
attached to central processing kit,
valves to open/close for each process.
• Sepax-S100, Biosafe S.A.
• Zingsem, Transfusion, 2003
• Product positive rate—7.5%, similar to that
of literature
• Unable to demonstrate superiority of
“functionally-closed system”
Functionally Closed System
• Fluids intrinsic to sterilized kit
• No flexibility of anticoagulation
• Sterile filters used for added reagents
How Closed is Closed?
• A matter of degree, with nothing
completely closed as some air and
starting material (blood) enter the
system and may not be sterile.
• Closed remains a relative term
Clinical Balance
• Risk of Infusion of Positive Products
• Very low with the current clinical
•
practice of often giving antibiotics, but
even without antibiotics, symptoms are
few
Vast majority of programs have SOPs
addressing culture-positive products
• Alternatives to use of positive products
• No treatment
• Recollection
Risk of Recollection
• Healthy donor may need catheter reinserted
• Autologous donor may have
underlying disease increasing
donation risk
Risks of Collection
• During period of report
• Two patients with amyloid died
during mobilization/collection (not
while on machine)
• One central catheter migrated to
pericardial space
• One central catheter created AV
fistula in thorax
Strategies for Reducing Positive
Culture Rates
• Improved screening of donors
• Drawing blood cultures 48 hours prior
•
•
to collection
• Cost: 100-200 blood cultures to
detect a bacteremia, and difficult to
measure benefit
• Some bacteremias are transient
(clostridium) and won’t be detected
Clean room environment does not have a
clear benefit
“Closed” systems-some additional
protection for post-donor sources
Summary
• Infusion of culture-positive HPC products appears
to be associated with minimal toxicity when
associated with usual clinical practice and
precautions
• The type of bacterium detected may affect the
clinical decision whether or not to use the product
• HPCs are not analogous to blood products in
ease or risk of replacement
• Overall risk to the patient AND donor for
recollection must be balanced against the
assessed risk of infusion of culture-positive
product