Protective Role of Intravesical BCG in COVID-19 Severity - Beyond the Abstract

COVID 19 is a pandemic never seen by mankind before. The infection has changed the priority and management of various urologic diseases. Today, deferring of treatments is being discussed, mainly in uro-oncology diseases.


On the other hand, intravesical Bacillus Calmette Guerin (BCG) not only generates a bladder inflammatory response; it induces a systemic effect with increased levels of IgG.1 The potential protective role of instillation of BCG in patients with NMIBC against diagnosis and aggressiveness of COVID-19 has not been published or described in the literature.

We compared our COVID-19 patients in BCG treatment (mean age 73 years) with the overall population of the same age group (70-79 years). According to our results, patients in BCG instillations have more cumulative incidence (24.6%) of COVID-19 compared with accumulated Chilean incidence at 70–79 years (6.3%). However, the fatality rate of COVID-19 patients in BCG treatment was less (2.3%) than the Chilean fatality rate in people with 70–79 years (14%).

According to our results, BCG instillations do not protect against infection but reduces mortality/severity. This finding is fundamental because recent evidence suggests that patients with cancer are at higher risk of infection for SARS-CoV-2 and may have poorer outcomes.2 Thus, it has been proposed to defer instillations with BCG by at least 3 weeks due to the risk of increasing severity in patients with COVID-19.3 Moreover, according to recommendations from the EAU NMIBC Guidelines Panel applicable during the COVID-19 pandemic, in cases of low intermediate risk, the BCG instillations would be deferred for at least 6 months. However, according to our data, intravesical BCG would be beneficial in case of infection since it would decrease the illness’ severity (and mortality).

Today, Chile is the world's third country world in the ranking of the total population that received at least one vaccine dose (38%).4 Our results were obtained before the start of the vaccination campaign in Chile. The aim of the campaign was to vaccinate the elderly in the first place. Our results could probably change with the effect of the vaccine in this population. Finally, more studies are needed in order to confirm our findings.

Written by: Ignacio F. San Francisco, Profesor Asociado, Jefe Departamento de Urología, Facultad de Medicina, Pontificia Universidad Católica de Chile & Pablo A. Rojas, Departamento de Urología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile

References:

  1. Zlotta A, Drowart A, Huygen K et al. Humoral response against heat shock proteins and other mycobacterial antigens after intravesical treatment with BCG in patients with superficial bladder cancer. Clin Exp Immunol 1997; 109: 157–65.
  2. Liang W, Guan W, Chen R et al. Cancer patients in SARS-CoV-2 infection: a nationwide analysis in China. Lancet Oncol 2020; 21: 335–7.
  3. Lenfant L, Seisen T, Loriot Y, Rouprêt M. Adjustments in the Use of Intravesical Instillations of Bacillus Calmette-Guérin for High-risk Non-muscle-invasive Bladder Cancer During the COVID-19 Pandemic. Eur Urol 2020; 78(1): 1-3.
  4. https://ourworldindata.org/covid-vaccinations

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