Comparison of NLR, PLR, and CRP in First-Episode Drug-Naive vs. Chronic Schizophrenia and Their Association with Symptom Severity

A Cross-Sectional Study - Full Protocol

1. TITLE

2. BACKGROUND AND RATIONALE

• Do not compare drug-naive first-episode vs. chronic medicated patients in the same cohort
• Use heterogeneous symptom scales (only BPRS, only CGI) without multimodal scale assessment
• Rarely correlate all three biomarkers simultaneously against positive, negative, and general psychopathology subscores
• Are conducted in Western/East Asian populations with limited data from South Asian contexts

3. AIM AND OBJECTIVES

Primary Aim

Secondary Objectives

1. To assess the correlation of NLR, PLR, and CRP with symptom severity (PANSS total, positive, negative, and general psychopathology subscales) in both groups.
2. To determine whether any of the three inflammatory markers can serve as a predictor of symptom severity.
3. To compare NLR, PLR, and CRP across different phases: drug-naive first episode vs. chronic stable vs. chronic acutely exacerbated schizophrenia.
4. To examine gender differences in inflammatory marker profiles.
5. To assess correlation with duration of illness and number of hospitalizations.

4. STUDY DESIGN

5. STUDY POPULATION

Groups

6. SAMPLE SIZE

• Alpha = 0.05 (Z = 1.96), Power = 80% (Z-beta = 0.84)
• Estimated minimum 40-50 per group
• Recommended: 60 per group x 4 groups = 240 participants total (with 10-15% attrition buffer = ~270)

7. INCLUSION CRITERIA

Patient Groups (A, B, C)

• Age 18-65 years
• Diagnosed with schizophrenia according to DSM-5 / ICD-10 criteria
• Both genders
• Able to give informed consent (or consent by guardian if required)
• Group A specific: Drug-naive (no prior antipsychotic, mood stabilizer, or steroid use ever), first psychotic episode within 1-2 years of onset
• Groups B & C specific: Diagnosis of schizophrenia confirmed for >2 years, currently receiving antipsychotic treatment

Healthy Controls (Group D)

• Age and gender matched to patient groups
• No personal or first-degree family history of psychiatric illness
• No current medical illness, infection, or medications

8. EXCLUSION CRITERIA

All Groups

• Active infections (viral, bacterial, fungal) or fever at time of blood sampling
• Autoimmune disorders (rheumatoid arthritis, SLE, IBD, etc.)
• Hematological disorders or malignancies
• Pregnancy or lactation
• Chronic inflammatory conditions (COPD, asthma, chronic liver disease, CKD, HIV)
• Substance use disorder (other than tobacco) - confirmed by history and urine drug screen
• Obesity (BMI >30) - as adipose tissue itself elevates CRP
• Recent surgery or trauma within past 3 months
• Use of NSAIDs, corticosteroids, immunosuppressants within 4 weeks
• Patients with comorbid neurological disorders (epilepsy, traumatic brain injury)
• Schizoaffective disorder, bipolar disorder with psychosis, or drug-induced psychosis
• Refusal to provide blood sample or written consent

9. EXAMINATION AND ASSESSMENTS

A. Sociodemographic and Clinical Data

• Age, gender, education, occupation, socioeconomic status, marital status
• Diagnosis, duration of illness, number of hospitalizations
• Current antipsychotic medication (name, dose, duration) - for Groups B & C
• Smoking status (pack-years)
• BMI, blood pressure
• Family history of psychiatric illness

B. Psychiatric Assessment / Symptom Severity Scales

C. Laboratory Investigations

10. PROCEDURE / STUDY FLOW

Screening -> Informed Consent -> Sociodemographic Proforma
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DSM-5 Diagnosis Confirmation (by treating psychiatrist)
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Psychiatric Rating (PANSS, BPRS, CGI-S, GAF, CDSS) - Same day
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Blood Sample Collection (fasting, morning) -> CBC + CRP + Metabolic panel
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Data Entry -> Calculate NLR, PLR, hs-CRP
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Statistical Analysis

11. STATISTICAL ANALYSIS

• Descriptive statistics: Mean ± SD or median (IQR) for continuous variables; frequency (%) for categorical
• Group comparisons: One-way ANOVA / Kruskal-Wallis test for NLR, PLR, CRP across 4 groups
• Post-hoc test: Tukey's / Bonferroni for pairwise comparisons
• Correlation: Pearson's or Spearman's correlation between inflammatory markers and PANSS subscores, BPRS, CGI-S, GAF
• Regression: Multiple linear regression to identify predictors of PANSS total score
• ROC curve: To determine optimal cut-off values of NLR/PLR/CRP for identifying high symptom burden
• Gender subgroup analysis
• Software: SPSS v25 or R
• Significance level: p < 0.05

12. ETHICAL CONSIDERATIONS

• IEC/IRB approval from institutional ethics committee
• Written informed consent from all participants
• Waiver of consent for patients with acute psychosis (consent by guardian + patient assent when possible)
• Patient data confidentiality and coding
• No extra cost to patients (blood drawn during routine workup where possible)

13. NOVELTY OF THE STUDY

1. Simultaneous three-group patient comparison: Most studies compare schizophrenia vs. healthy controls. This study adds a three-way patient comparison - drug-naive first episode vs. chronic stable vs. chronic acute relapse - which will clarify whether inflammation is a trait marker (present throughout illness) or state marker (worse in acute episodes and early illness).
2. Triple biomarker panel (NLR + PLR + CRP together): Most studies examine NLR alone or NLR+PLR without CRP. The simultaneous comparison of all three in one cohort with standardized collection provides a more complete inflammatory picture.
3. Multimodal symptom scale assessment: Using PANSS (positive, negative, general) + BPRS + CGI + GAF simultaneously allows for granular correlation analysis - especially separating inflammatory correlates of positive versus negative symptoms, which behave differently (CRP correlates with positive symptoms per Fernandes et al. meta-analysis; negative symptoms may follow a different pattern).
4. hs-CRP inclusion: High-sensitivity CRP is more sensitive than standard CRP in detecting low-grade subclinical inflammation, which is characteristic of schizophrenia.
5. Drug-naive cohort is methodologically cleaner: Antipsychotics have immunomodulatory effects (e.g., clozapine increases inflammation; LAIs reduce NLR per Messina et al. 2024). Drug-naive patients allow assessment of "pure" illness-related inflammation unconfounded by medication.
6. South Asian population data: Most existing studies come from Chinese, Turkish, or European cohorts. This study fills a geographic and demographic gap in the literature.

14. CLINICAL CORRELATIONS AND SIGNIFICANCE

• If NLR/PLR/CRP are significantly higher in FEDS, this supports the inflammatory hypothesis as being present from illness onset, not secondary to chronicity or medication
• If chronic patients (especially acute relapse) show higher markers than stable chronic patients, it supports inflammatory markers as state markers of relapse
• If NLR/CRP correlate with PANSS positive scores, it supports the role of neuroinflammation in psychosis generation
• If inflammation correlates more with negative symptoms and functioning (GAF), it supports targeting inflammation to improve negative symptoms - which are currently more treatment-resistant
• These markers could become routine clinical screening tools for identifying a "high-inflammation" subtype of schizophrenia that may benefit from adjunctive anti-inflammatory treatment (e.g., aspirin, COX-2 inhibitors, minocycline, omega-3 fatty acids)

15. LIMITATIONS

1. Cross-sectional design: Cannot establish causality or temporal relationship between inflammation and symptoms. Repeated measurements would be required.
2. Medication confounding in chronic groups: Antipsychotics (especially clozapine) independently affect NLR and CRP. Although this is accounted for in subgroup analysis, complete control is not possible.
3. Single-centre study: May limit generalizability and introduce selection bias.
4. Small-to-moderate sample size: May not capture gender-specific effects reliably, particularly for the drug-naive group where recruitment is challenging.
5. CRP influenced by BMI: Obese participants are excluded, but BMI variation within the normal range still confounds CRP.
6. Smoking confounding: Smoking (common in schizophrenia) elevates NLR and WBC. Controlling statistically is possible but not fully eliminated.
7. Absence of cytokine assays: NLR, PLR, CRP are indirect proxies. Actual cytokine levels (IL-6, TNF-alpha, IL-1beta) would provide more mechanistic data.
8. Single time point for drug-naive patients: Does not capture how markers change after treatment initiation.
9. Recruitment bias: Drug-naive patients are increasingly rare in accessible healthcare settings; those seen may represent more severe or treatment-resistant cases.
10. Lack of neuroimaging: Cannot correlate peripheral inflammation with CNS inflammation or structural brain changes.

16. WHAT WE WILL DO IN THIS STUDY - SUMMARY

1. Recruit 4 groups (FEDS, chronic stable, chronic acute relapse, healthy controls) from the inpatient and outpatient psychiatric units
2. Confirm DSM-5 diagnosis; document sociodemographic and clinical details
3. Rate symptom severity using PANSS, BPRS, CGI-S, GAF, CDSS on the same day as blood sampling
4. Collect fasting morning venous blood for CBC with differential, hs-CRP, ESR, metabolic panel, urine drug screen
5. Calculate NLR = neutrophils/lymphocytes; PLR = platelets/lymphocytes
6. Compare NLR, PLR, CRP across the 4 groups using ANOVA and post-hoc tests
7. Correlate NLR, PLR, CRP with PANSS total, positive, negative, general psychopathology subscores
8. Run regression to identify which biomarker best predicts symptom severity
9. Perform gender-stratified and illness-duration subgroup analyses
10. Derive ROC cut-off values for markers as clinical predictors

15 RELATED ARTICLES - WITH PubMed Links and Brief Summaries

All links below are PubMed hyperlinks (freely accessible abstract + many open-access full texts). Sample sizes are noted for each.

QUICK REFERENCE - ALL 15 ARTICLES

KEY TAKE-AWAYS FOR YOUR STUDY

• The most important gap your study fills is the simultaneous three-group patient comparison (drug-naive + chronic stable + chronic acute) with three biomarkers and multimodal symptom scales including PANSS subscales
• Keep hs-CRP (not standard CRP) where possible for better sensitivity
• Collect blood before morning antipsychotic dose in the chronic groups to minimize pharmacokinetic interference
• Document smoking pack-years and BMI carefully - they are the biggest confounders for all three markers
• The Mojadadi et al. (2024, PMID 38092259) study is your closest design comparator - address directly how your study differs (drug-naive group, comparison with controls, three-group design)