Tuberculin specific T-cell response after intravesical BCG-instillations.

Adjuvant immunomodulating therapy by application of Bacille Calmette-Guérin
(BCG) fluid as lavage fluid is a common used treatment for patients with
superficial bladder carcinoma. The BCG vaccine is based on a viable but
attenuated strain of bovine tuberculosis and has been available since the 20th
years of the past century. Almost half of the global population has been
administered with the vaccine for prevention of severe tuberculosis infections
in children. Application of a suspension with BCG-vaccine induces a substantial
local cellular immune response with proven antitumor activity.
Ever since BCG-lavages have been applied, patients with superficial bladder
carcinoma have a an improved prognosis for recurrence (20-40% reduction).
Complications related to bladder lavages are frequent. Fever (75%) and
haematuria (24%) are the most predominant side effects. Some of these side
effects may be explained by traumatic catheterization or local imuune
responses. Because BCG-vaccine contains a live attenuated strain infections are
conceivable. This is estimated to occur in approximately 5% of patients with
bladder carcinoma treated with BCG-vaccine (3).
Infections may be limited to bladder or prostate but may become manifest
elsewhere in the body (lungs, aorta). Clinical symptoms of these infections are
often not much specific and may for instance be manifest only by fever.
Therefore BCG-infection (BCG-itis) or inflammation after application of BCG may
be ranked low in the differential diagnosis.
In literature there is disagreement about the severe side effects of BCG
lavages being based on an allergic immune respons or on an actual infection.
Both are conceivable because the BCG-vaccine strain may not always be detected
in affected organs. In addition, the BCG strain may hard to culture but
nevertheless it was demonstrated in ample cases that BCG is frequently present
in affected organs.
Hence, diagnosis of these infections may be cumbersome but still these
infections require powerful and adequate antimycobacterial therapy.
The Elispot procedure is based on antigen specific T-cell recognition after
contact with an (infectious) agent. The PPD-antigen can also be used in the
Elispot technique. Previously, we were able to demonstrate that not only
cellular immune responses directed to mycobacterium tuberculosis may be
identified with PPD-antigen, but also against BCG vaccine and non-tuberculous
mycobacteria.

1. Monitoring of cellular (T-cel) specifc immune response in bladder and
bloodsamples after intravesical BCG-
therapy.
2. Monitoring and comparing T-cell responses after BCG therapy in patients with
clinical BCG-related complications to the T-
cell responses in patient without symptoms.
3. To determinatie the potential of measuring PPD-specific T-cell activity for
diagnostis and prediction of BCG-therapy
related complications.

At first a pilot study will be initiated aiming to establish the performance of
Elispot PPD on T-cells isolated from urine and/or BCG-lavage. In order to
obtain reliable and reproducible IGRA results, these samples must contain
sufficient numbers of reactive T-cells. This will provide data about cell
reaction in the bladder after BCG-instillations.
Initially 25 patient samples will be tested.
Urine will be drained directly from the bladder through a catheter before
administering the BCG-instillation and a portion of midstream urine will be
collected for elispot. Subsequently, the empty bladder will be rinsed out with
100 cc NaCl solution. This solution will be collected for elispot. Finally
BCG-instillation will be performed.

In phase 2 we will analyse the PPD specific T-cell responses of 50 patients
after receiving BCG-instillations. Via a catheter urine will be drained
directly from the bladder before administering the BCG-instillation and a
portion of midstream urine will be collected for elispot. Subsequently, the
empty bladder will be rinsed out with 100 cc NaCl solution. This solution will
be collected for elispot. Finally BCG-instillation will be performed.The
obtained research data will be related to patient data as documented in the
CRF's. By doing this we hope to be able to monitor the basal PPD specific
immuunresponses against BCG. Prior to BCG-installations in weeks 0, 1, 2, 3, 4,
5 en 6, blood samples and bladderlavage fluids are analysed on the presence and
activity of PPD specific T-cells. After 12 weeks patients attend the urology
department for control cystoscopy and blood and bladderlavage fluid will be
drawn again for elispot. Plasma and urine will be frozen at -80 C for future
IFN-gamma and/or cytokine measurements.

The third study phase aims on specific analysis of patiënts suspected of having
infectious BCG-related complications.
Patients will be stratified based on the criteria given in table 1 of the study
protocol. We hope to include 20 patients during a 2 years traject and to
substantiate the possibility of including 20 patients the study will convert to
a multicentre model in which patients from both Diakonessen Hospital Utrecht
and St. Antonius Ziekenhuis will be included.
When patients develop complications (as mentioned in the inclusioncriteria)
during the regular treatment with BCG-instillations, this traject will be
stopped and blood and bladder lavage fluid will be collected. This time point
will be regarded as week 0 and will subsequently be repeated after 1, 2, 3, 4,
5, 6 en 12 weeks. In this way hope to gain insight in how immune responses
develop in patients with complications after BCG-therapy.

n.a.