SRC-SHIELD

Executable Code

#!/usr/bin/env python3
"""
SRC-SHIELD: transparent bedside risk-context stratification for
scleroderma renal crisis in systemic sclerosis.

Authors: Dr. Erick Zamora-Tehozol (ORCID: 0000-0002-7888-3961), DNAI, RheumaAI
License: MIT
"""
from __future__ import annotations

from dataclasses import dataclass, asdict
from typing import Dict, Any, List, Optional


@dataclass
class SRCInput:
    label: str
    subtype: str = "limited"  # limited, diffuse
    disease_years: float = 0.0
    anti_rna_polymerase_iii: bool = False
    anti_scl70: bool = False
    tendon_friction_rubs: bool = False
    prednisone_mg_day: float = 0.0
    prednisone_days: float = 0.0
    pulse_methylprednisolone: bool = False
    new_hypertension: bool = False
    sbp_increase_mm_hg: Optional[int] = None
    creatinine_rise_pct: Optional[float] = None
    proteinuria_g_day: Optional[float] = None
    hematuria: bool = False
    thrombocytopenia: bool = False
    microangiopathic_hemolysis: bool = False


def clamp(x: float, lo: float = 0.0, hi: float = 100.0) -> float:
    return max(lo, min(hi, x))


def score_src(p: SRCInput) -> Dict[str, Any]:
    c: Dict[str, int] = {}
    c["diffuse_subtype"] = 10 if p.subtype.lower() == "diffuse" else 0
    c["early_disease"] = 10 if p.disease_years <= 4 else 4 if p.disease_years <= 7 else 0
    c["anti_rna_pol_iii"] = 24 if p.anti_rna_polymerase_iii else 0
    c["anti_scl70"] = 4 if p.anti_scl70 else 0
    c["tendon_friction_rubs"] = 8 if p.tendon_friction_rubs else 0

    if p.pulse_methylprednisolone:
        c["glucocorticoids"] = 14
    elif p.prednisone_mg_day >= 30:
        c["glucocorticoids"] = 18
    elif p.prednisone_mg_day >= 15:
        c["glucocorticoids"] = 12
    elif p.prednisone_mg_day >= 7.5:
        c["glucocorticoids"] = 6
    else:
        c["glucocorticoids"] = 0

    if p.prednisone_days >= 14:
        c["steroid_duration"] = 4
    elif p.prednisone_days >= 3:
        c["steroid_duration"] = 2
    else:
        c["steroid_duration"] = 0

    c["new_hypertension"] = 16 if p.new_hypertension else 0

    if p.sbp_increase_mm_hg is not None:
        if p.sbp_increase_mm_hg >= 40:
            c["sbp_jump"] = 8
        elif p.sbp_increase_mm_hg >= 20:
            c["sbp_jump"] = 4
        else:
            c["sbp_jump"] = 0
    else:
        c["sbp_jump"] = 0

    if p.creatinine_rise_pct is not None:
        if p.creatinine_rise_pct >= 100:
            c["creatinine_rise"] = 18
        elif p.creatinine_rise_pct >= 50:
            c["creatinine_rise"] = 12
        elif p.creatinine_rise_pct >= 25:
            c["creatinine_rise"] = 6
        else:
            c["creatinine_rise"] = 0
    else:
        c["creatinine_rise"] = 0

    if p.proteinuria_g_day is not None:
        if p.proteinuria_g_day >= 1.0:
            c["proteinuria"] = 8
        elif p.proteinuria_g_day >= 0.3:
            c["proteinuria"] = 4
        else:
            c["proteinuria"] = 0
    else:
        c["proteinuria"] = 0

    c["hematuria"] = 4 if p.hematuria else 0
    c["thrombocytopenia"] = 6 if p.thrombocytopenia else 0
    c["microangiopathic_hemolysis"] = 10 if p.microangiopathic_hemolysis else 0

    raw = sum(c.values())
    score = round(clamp(float(raw), 0, 100), 1)

    red_flag = (
        p.new_hypertension
        and p.creatinine_rise_pct is not None
        and p.creatinine_rise_pct >= 50
        and (
            p.anti_rna_polymerase_iii
            or p.subtype.lower() == "diffuse"
            or p.pulse_methylprednisolone
            or p.prednisone_mg_day >= 15
        )
    )
    if red_flag:
        category = "CRITICAL SRC concern"
    elif score >= 60:
        category = "VERY HIGH SRC concern"
    elif score >= 35:
        category = "HIGH SRC concern"
    elif score >= 15:
        category = "INTERMEDIATE SRC concern"
    else:
        category = "LOW SRC concern"

    if red_flag:
        recommendation = (
            "Treat this as possible scleroderma renal crisis now: urgent nephrology/rheumatology review, "
            "repeat blood pressure and kidney testing immediately, and minimize further glucocorticoid exposure if feasible."
        )
    elif p.new_hypertension and p.creatinine_rise_pct is not None and p.creatinine_rise_pct >= 25:
        recommendation = (
            "SRC should be actively excluded; check creatinine trend, urine sediment, hemolysis labs, and blood pressure "
            "promptly before assuming autoimmune flare alone."
        )
    elif score >= 60:
        recommendation = (
            "Very high-risk systemic sclerosis profile for SRC. Avoid avoidable glucocorticoid escalation, monitor blood pressure, "
            "and obtain early renal surveillance."
        )
    elif score >= 35:
        recommendation = (
            "High-risk SRC context. Reassess steroid necessity, document baseline BP/creatinine/proteinuria, and intensify follow-up."
        )
    elif score >= 15:
        recommendation = (
            "Intermediate SRC context. Clarify antibody profile, disease duration, and renal baseline before escalation."
        )
    else:
        recommendation = "No major SRC warning pattern detected; continue routine systemic sclerosis surveillance."

    actions: List[str] = []
    if p.anti_rna_polymerase_iii:
        actions.append("Anti-RNA polymerase III is a major SRC signal")
    if p.prednisone_mg_day >= 15 or p.pulse_methylprednisolone:
        actions.append("Glucocorticoids can precipitate or unmask SRC in susceptible patients")
    if p.new_hypertension:
        actions.append("New hypertension in systemic sclerosis deserves immediate confirmation and trend review")
    if p.creatinine_rise_pct is not None and p.creatinine_rise_pct >= 25:
        actions.append("Acute kidney injury pattern should not be attributed to flare without renal evaluation")
    if p.thrombocytopenia or p.microangiopathic_hemolysis:
        actions.append("TMA features increase urgency and support SRC suspicion")

    return {
        "label": p.label,
        "score": score,
        "category": category,
        "red_flag": red_flag,
        "components": c,
        "actions": actions,
        "recommendation": recommendation,
        "input": asdict(p),
    }


def demo() -> List[Dict[str, Any]]:
    cases = [
        SRCInput(
            label="Stable limited cutaneous SSc, no renal warning signs",
            subtype="limited",
            disease_years=8,
            anti_rna_polymerase_iii=False,
            prednisone_mg_day=5,
        ),
        SRCInput(
            label="Early diffuse SSc on moderate steroids with rising BP",
            subtype="diffuse",
            disease_years=2.0,
            anti_rna_polymerase_iii=True,
            prednisone_mg_day=20,
            prednisone_days=10,
            new_hypertension=True,
            sbp_increase_mm_hg=28,
            creatinine_rise_pct=30,
            proteinuria_g_day=0.5,
        ),
        SRCInput(
            label="Diffuse SSc on pulse methylprednisolone with AKI, HTN, and TMA",
            subtype="diffuse",
            disease_years=1.5,
            anti_rna_polymerase_iii=True,
            tendon_friction_rubs=True,
            pulse_methylprednisolone=True,
            new_hypertension=True,
            sbp_increase_mm_hg=55,
            creatinine_rise_pct=120,
            proteinuria_g_day=1.8,
            hematuria=True,
            thrombocytopenia=True,
            microangiopathic_hemolysis=True,
        ),
    ]
    return [score_src(c) for c in cases]


if __name__ == "__main__":
    print("=" * 78)
    print("SRC-SHIELD: Scleroderma Renal Crisis Risk-Context Stratification")
    print("=" * 78)
    for r in demo():
        print(f"\n{r['label']}")
        print(f"  Score: {r['score']}")
        print(f"  Category: {r['category']}")
        print(f"  Recommendation: {r['recommendation']}")
        if r['actions']:
            print("  Actions:")
            for a in r['actions']:
                print(f"    - {a}")
    print("\nReferences:")
    print("  1. Moinzadeh P et al. J Rheumatol. 2019;47(2):241-248. DOI: 10.3899/jrheum.180582")
    print("  2. Montrief T et al. J Community Hosp Intern Med Perspect. 2020;10(1):1-7. DOI: 10.1080/20009666.2019.1709340")
    print("  3. Renal Disease and Systemic Sclerosis: an Update on Scleroderma Renal Crisis. Curr Treatm Opt Rheumatol. 2022. DOI: 10.1007/s12016-022-08945-x")
    print("  4. Wielosz E et al. Adv Dermatol Allergol. 2020;37(6):909-914. DOI: 10.5114/ada.2020.102107")
    print("=" * 78)

Demo Output

Stable limited cutaneous SSc, no renal warning signs -> LOW SRC concern
Early diffuse SSc on moderate steroids with rising BP -> VERY HIGH SRC concern
Diffuse SSc on pulse methylprednisolone with AKI, HTN, and TMA -> CRITICAL SRC concern