Impact of doxycycline on mycoplasma pneumonia treatment and cancer prognosis in pediatric leukemia patients post-chemotherapy: a target trial emulation.

Abstract

Background: Acute leukemia is the most common malignancy in children. While chemotherapy is effective, it significantly compromises immune function, leading to a high incidence of infectious complications, such as secondary pneumonia, particularly Mycoplasma pneumonia (MP). The treatment of infections in pediatric leukemia patients faces challenges such as antibiotic resistance and drug interactions during chemotherapy.

Objective: This study aims to evaluate the therapeutic efficacy and safety of doxycycline in treating MP in pediatric leukemia patients post-chemotherapy, as well as it impact on chemotherapy continuity.

Methods: This study employed a target trial emulation design using retrospective data from pediatric leukemia patients diagnosed with MP. Patients aged 12-17 years with confirmed leukemia and clinical evidence of pneumonia following chemotherapy were included. Doxycycline was compared to azithromycin and other empirical treatments. Follow-up assessments at 3 days, 5 days, 30 days, and 180 days evaluated fever resolution, radiological improvement, additional interventions, and adverse events. Statistical analyses included Kaplan-Meier survival analysis and Cox proportional hazards models.

Results: In Trial 2, doxycycline demonstrated a significantly higher treatment success rate than other empirical treatments (87.72% vs. 73.13%, P = 0.013) and was associated with faster fever resolution (P = 0.048) and shorter time to chest X-ray improvement (P = 0.048). The 30-day survival rate was significantly higher in the Doxycycline group compared to other empirical treatments (100% vs. 91.04%, P = 0.019). Fewer patients require additional interventions such as ICU admission (P = 0.019). Furthermore, patients in the Doxycycline group had a significantly higher likelihood of completing chemotherapy without delays (84.21% vs. 59.70%, P = 0.01). In Trial 1, no significant differences were observed in treatment success rate, fever resolution time, hospitalization duration, or chemotherapy tolerance between Doxycycline and Azithromycin (P > 0.05).

Conclusion: Doxycycline, as a broad-spectrum antibiotic, demonstrates efficacy comparable to azithromycin in treating MP with advantages in reducing chemotherapy-related delays, hospitalization duration, and the need for additional interventions. It enhances chemotherapy tolerance and continuity. Doxycycline may serve as an economical and effective alternative for managing post-chemotherapy infections in pediatric leukemia patients, especially in cases of antibiotic resistance or intolerance.