Background Clozapine is the recommended treatment for managing
treatment-resistant schizophrenia (TRS), and immunological mechanisms may be
involved in its unique antipsychotic efficacy. This study investigated whether
baseline immune abnormalities measured with blood cell count ratios can predict
the clinical response after initiating treatment with clozapine in patients with
clozapine naïve TRS.
Methods A longitudinal design was developed, involving 32 patients
diagnosed with treatment-resistant, clozapine-naïve schizophrenia-spectrum
disorder. Patients were evaluated at baseline before clozapine starting and 8
weeks of follow-up. Psychopathological status and immune abnormalities (blood
cell count ratios: neutrophil-lymphocyte ratio [NLR], monocyte-lymphocyte ratio
[MLR], platelet-lymphocyte ratio [PLR] and basophil-lymphocyte ratio [BLR]) were
evaluated in each visit.
Results Baseline NLR (b=− 0.364; p=0.041) and MLR (b =− 0.400; p=0.023)
predicted the change in positive symptoms over the 8-week period. Patients who
exhibited a clinical response showed higher baseline NLR (2.38±0.96 vs.
1.75±0.83; p=0.040) and MLR (0.21±0.06 vs. 0.17±0.02; p=0.044) compared to
non-responders. In the ROC analysis, the threshold points to distinguish between
responders and non-responders were approximately 1.62 for NLR and 0.144 for MLR,
yielding AUC values of 0.714 and 0.712, respectively. No statistically
significant differences were observed in the blood cell count ratios from
baseline to the 8-week follow-up.
Conclusion Our study emphasizes the potential clinical significance of
baseline NLR and MLR levels as predictors of initial clozapine treatment
response in patients with TRS. Future studies with larger sample sizes and
longer follow-up periods should replicate our findings.