TNF and chronic cystitis: However, though TNFɑ depletion made Resolved mice more susceptible to acute cystitis upon challenge, a single dose of anti-TNFɑ antibody was insufficient to overcome their resistance to chronic infection, as 0 of 11 mice treated with anti-TNFɑ developed chronic cystitis lasting 4 weeks, compared to 0 of 11 mice treated with isotype.