1. Recurrent Respiratory Papillomatosis (RRP):
Basic Science to Clinical Studies
Mark J. Shikowitz, MD
Bettie M. Steinberg, PhD
Long Island Jewish Medical Center
Schneider Children’s Hospital
North Shore – LIJ Research Institute
Presented at the American Academy of Otolaryngology- Head
and Neck Surgery, Orlando FL September 2003

2. Respiratory Papillomas
Benign tumors of airway - larynx > trachea >lungs
Caused by Human Papillomaviruses types 6 and 11
Frequently recur - can require more than 100 operations
Recurrence due to activation of latent infection
Become malignant in approximately 3% of patients
Irradiation of papillomas increases malignant
conversion – 16-fold increased risk *
*Lindeberg H, Elbrond O. Malignant tumours in patients with a
history of multiple laryngeal papillomas: the significance of
irradiation. Clin Otolaryngol. 16:149-51 1991.

3. Appearance of Mild and Severe
Larynx Papillomas

4. Demographics of RRP
International Data
− incidence 3.8 - 7.0 / million population/ year
− prevalence 1/100,000
− two peaks - juvenile onset 2-5 years of age
− adult onset 20-40 years of age
− juvenile 1:1 male/female, adult 2:1
LIJ Data
− total patients treated 254
− adult onset: 138 juvenile onset: 116
− 175 males, 79 females

5. Studies in Laboratory
Signal transduction - control of cell growth and
differentiation
Regulation of latent infection
Host immune responses to HPV
− T cell functions
− Suppression of MHC expression by HPV protein
Efficacy of photodynamic therapy – completed
Efficacy of Celebrex therapy

6. Latency is the Key to This Disease
Latency: presence of viral DNA in clinically and histologically
normal respiratory tissue
Source of recurrent laryngeal disease
− recurrence not due to “spread of virus” during surgery
− all patients have patchy latent infection in larynx, even if in
remission for 20+ years
Disease is due to focal activation of latency
Cannot cure disease unless eliminate latency - only control

7. Papillomavirus Life Cycle
Virus
Production
Normal epithelium (if permissive)
Late Viral
RNA, DNA
Infection squame
Early Viral
with virus
n RNA
ati o
tiv Viral DNA
ac maintenance
Papilloma
Latent Infection Co-carcinogen(s)
Cancer Rare event

8. Tracheal Papillomatosis and Tracheal Latency
Tracheal disease less frequent than laryngeal disease
− 35/254 (13.7%) of our patients have tracheal
disease
Several possible explanations for low prevalence
− Low rate of HPV infection
− Low rate of HPV latency
− Low rate of activation of latent infection
We have asked which of these explanations might be
correct

9. HPV Latency is Equal in Larynx and Trachea
60
Perent biopsies
40
20
0
Larynx Trachea

10. Conclusions - Take Home Message
Nearly all patients carry latent tracheal HPV DNA
Therefore, low frequency of tracheal disease not due to
infection rate or establishment of latency
Low rate of tracheal disease must be due to tissue-
specific factors required for activation of HPV DNA
− Permissive tissue for virus is stratified squamous
epithelium
− Trachea normally ciliated columnar
− Must avoid inducing squamous metaplasia (e.g.
trach tube, smoking)

11. Design of Photodynamic Therapy Study
Patients with 3 or more surgeries in past year or tracheal
involvement eligible
Randomized - two treatment times (6 and 15 months)
after enrollment - late group “control”
One dose Foscan® - 0.15 mg/kg
Wash-out time 6 days
Light dose (652 nm) adults: 80-100J, children: 60-80J
Score disease at 3 month intervals for 1+ yr after PDT
Study now ended – PDT improved disease for some
patients, but did not prevent long-term recurrence

12. Results of PDT Study
Percent Score at Entry Response to PDT
500
Median and Range
250 Controls
- PDT treated
200
150
100
50
3 6 9 12 15 18 3 6 9 12 15 18 21
PDT
p= 0.006 Months After Enrollment

13. Design New Celebrex Study
Multi-centered study, other sites planned
− University of Iowa
− University of Alabama, Birmingham
− University of Pittsburgh
Patient enrollment requirement: Adults with 3 or more
surgeries in past year or tracheal involvement
Randomized - two start times (6 and 12 months) after
enrollment - late group “control”, everyone gets Celebrex
Celebrex NOT Standard Dose – must be managed
carefully as per study
Score disease at 3 month intervals for total of 2 years

14. Role of Host Immune System in Disease
Simple question - why do patients have recurrent
disease?
Approx. 5% of population carries latent HPV in larynx,
RRP prevalence is 1/100,000
Are RRP patients immunocompromised?
Answer: No! Standard tests show no defect in immune
system and patients no more likely to have other
infections.
Must be specific for HPV

15. Immune Response in RRP
Cell-mediated Immunity Humoral Immunity
TH1 Cell TH2 Cell
Ifn-γ,, IL-2 IL-4, IL-10
CD 8
T-cell
(CD28)
MHC Class II
T-cell receptor
B7 with viral protein
(MHC Class I)
Infected epithelial cell
Antigen Presenting Cell

16. Take Home Message
Many patients have antibodies against HPV
Specific defect in the ability of RRP patients to generate a
cell-mediated response to HPV infection - not general
immune suppression
This could explain the ability of the virus to activate latent
infection repeatedly without developing an effective immune
response
Celebrex study will determine whether it improves immune
response.