To the Editors:
Intravesical bacille Calmette–Guérin (BCG) therapy is an effective treatment for high-risk superficial bladder cancer. A nonspecific immune response is expected after instillation of BCG, an alive but attenuated strain of Mycobacterium bovis. Disseminated BCG disease is a rare but well known complication of this therapy. It occurs in approximately 1% of cases 1. Severe complications could occur with hepatitis and pneumonitis but bone marrow involvement is exceptional. There are limited data on factors associated with the risk of BCG infection. The role of CD4+ T-cells in controlling mycobacteria infection is well established and the susceptibility of HIV-infected individuals for tuberculosis is an argument for this 2. Nevertheless, CD8+ T-cells play a significant role in this control, in particular secreting interferon (IFN)-γ and killing infected cells given their cytotoxic potential 3. Furthermore, experimental studies have shown that CD8+ T-cells play an important role in the early control of mycobacteria infection in older mice 4, suggesting that this may be occurring in elderly people. The present study describes two disseminated BCG infections, including bone marrow involvement, in elderly patients. Severe CD8+ T-cell depletion was found in the two patients, which illustrates the importance of CD8+ T-cells in the early control of mycobacterial infection in humans.
The first patient was a 74-yr-old male, admitted in our department for fever and chills. He had concomitant weight loss of 6 kg and intense fatigue over the last 15 days. 3 months earlier he had undergone a trans-urethral resection for superficial bladder cancer. Treatment was completed by weekly instillation of BCG. A few days after the second instillation, the patient noted gradual onset of fever. 3 weeks after the onset of fever, he was referred to our hospital. Clinical examination gave no conclusive results but the biological results showed elevated C-reactive protein …