Kidney · LIVE

IgA nephropathy 5-year risk

IgAN predict

Compute 5-year risk of a 50% decline in eGFR or ESKD after kidney biopsy from the Barbour 2019 full International IgAN prediction model that does not use race or ethnicity.

LIVE $0.005 USDC GET /api/calc/igan_predict

Markdown: /docs/igan-predict.md · Canonical: https://magentlab.com/docs/igan-predict

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute 5-year risk of a 50% decline in eGFR or ESKD after kidney biopsy from the Barbour 2019 full International IgAN prediction model that does not use race or ethnicity.

When to use

When an agent already has age at biopsy, a caller-supplied eGFR, MAP, proteinuria in g/day, Oxford MEST scores, and whether RAS blockade and immunosuppression were in use at biopsy, and needs that paper's race-free 5-year risk. Not a biopsy diagnosis, not KFRE, and not the race/ethnicity model.

When not to use

• Not a medical device. Not a biopsy diagnosis, immunosuppression order, or RAS-blockade order. magent does not assay creatinine or urine protein and does not compute CKD-EPI eGFR.
• Barbour 2019 full model without race/ethnicity only (eTable 3). Does not ship the full model that includes Chinese, Japanese, White, or other race coefficients.
• Not KFRE and not a 50% eGFR-decline or ESKD diagnosis. Emits a 5-year percent, not a named risk class. Table 3 percentile bands are cohort-specific and are not returned.
• Derivation was adults 18 years or older with biopsy-proven idiopathic IgAN and without ESKD at biopsy. Age 18-120 is a magent adult clamp. Caller supplies eGFR.
• Predictors are at the time of biopsy, including RAS blockade and immunosuppression already in use. The model is not a treatment-response predictor for drugs started after biopsy.

Formula

LP = -0.320*(sqrt(egfr_ml_min_1_73m2) - 8.8) + 0.002*(map_mm_hg - 97) - 0.035*(ln(proteinuria_g_day) - 0.09) + 0.004*(map_mm_hg*ln(proteinuria_g_day) - 8.73) + 0.201*M1 - 0.035*E1 + 0.084*S1 + 0.700*T1 + 1.237*T2 + 0.101*T1*ln(proteinuria_g_day) - 0.321*T2*ln(proteinuria_g_day) - 0.017*(age_years - 38) + 0.118*RASB + 0.166*RASB*ln(proteinuria_g_day) - 0.266*immunosuppression; S0(t) = 1.0003754 - 0.1131641*u^2 + 0.0964763*u^2*ln(u), u = (t + 0.1)/100, t months; 5-year risk = 1 - S0(60)^exp(LP); Barbour 2019 eTable 3 full model without race/ethnicity only; M/E/S/T1/T2 RASB and immunosuppression are 0 or 1; natural log; caller supplies eGFR; not the race model; not KFRE

Citation

Title

Evaluating a new international risk-prediction tool in IgA nephropathy

Authors

Barbour SJ, Coppo R, Zhang H, Liu ZH, Suzuki Y, Matsuzaki K, Katafuchi R, Er L, Espino-Hernandez G, Kim SJ, Reich HN, Cattran DC, Feehally J; International IgA Nephropathy Network

Source

JAMA Intern Med. 2019;179(7):942-952

DOI

10.1001/jamainternmed.2019.0600

Worked example

Also searched as

• IgA nephropathy risk
• IgAN prediction
• Barbour 2019 IgAN
• International IgAN prediction
• MEST IgAN risk
• IgA nephropathy ESKD risk
• 50 percent eGFR decline IgAN

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/igan_predict?age_years=38&egfr_ml_min_1_73m2=77&map_mm_hg=97&proteinuria_g_day=1.1&mest_m=1&mest_e=0&mest_s=1&mest_t=0&rasb_at_biopsy=true&immunosuppression_at_biopsy=false

Full URL: https://api.magentlab.com/api/calc/igan_predict?age_years=38&egfr_ml_min_1_73m2=77&map_mm_hg=97&proteinuria_g_day=1.1&mest_m=1&mest_e=0&mest_s=1&mest_t=0&rasb_at_biopsy=true&immunosuppression_at_biopsy=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/igan_predict?age_years=38&egfr_ml_min_1_73m2=77&map_mm_hg=97&proteinuria_g_day=1.1&mest_m=1&mest_e=0&mest_s=1&mest_t=0&rasb_at_biopsy=true&immunosuppression_at_biopsy=false"

Parameters

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/igan_predict Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "age_years": "38",
      "egfr_ml_min_1_73m2": "77",
      "immunosuppression_at_biopsy": "false",
      "map_mm_hg": "97",
      "mest_e": "0",
      "mest_m": "1",
      "mest_s": "1",
      "mest_t": "0",
      "proteinuria_g_day": "1.1",
      "rasb_at_biopsy": "true"
    },
    {
      "age_years": "38",
      "egfr_ml_min_1_73m2": "77",
      "immunosuppression_at_biopsy": "false",
      "map_mm_hg": "97",
      "mest_e": "0",
      "mest_m": "1",
      "mest_s": "1",
      "mest_t": "0",
      "proteinuria_g_day": "1.1",
      "rasb_at_biopsy": "true"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/igan_predict",
  "items": [
    {
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Barbour SJ, Coppo R, Zhang H, Liu ZH, Suzuki Y, Matsuzaki K, Katafuchi R, Er L, Espino-Hernandez G, Kim SJ, Reich HN, Cattran DC, Feehally J; International IgA Nephropathy Network",
        "doi": "10.1001/jamainternmed.2019.0600",
        "id": "barbour-2019-igan",
        "pmid": "30980653",
        "source": "JAMA Intern Med. 2019;179(7):942-952",
        "title": "Evaluating a new international risk-prediction tool in IgA nephropathy"
      },
      "formula": "igan_predict",
      "formula_expression": "LP = -0.320*(sqrt(egfr_ml_min_1_73m2) - 8.8) + 0.002*(map_mm_hg - 97) - 0.035*(ln(proteinuria_g_day) - 0.09) + 0.004*(map_mm_hg*ln(proteinuria_g_day) - 8.73) + 0.201*M1 - 0.035*E1 + 0.084*S1 + 0.700*T1 + 1.237*T2 + 0.101*T1*ln(proteinuria_g_day) - 0.321*T2*ln(proteinuria_g_day) - 0.017*(age_years - 38) + 0.118*RASB + 0.166*RASB*ln(proteinuria_g_day) - 0.266*immunosuppression; S0(t) = 1.0003754 - 0.1131641*u^2 + 0.0964763*u^2*ln(u), u = (t + 0.1)/100, t months; 5-year risk = 1 - S0(60)^exp(LP); Barbour 2019 eTable 3 full model without race/ethnicity only; M/E/S/T1/T2 RASB and immunosuppression are 0 or 1; natural log; caller supplies eGFR; not the race model; not KFRE",
      "age_years": 38,
      "linear_predictor": 0.4287,
      "egfr_ml_min_1_73m2": 77.0,
      "map_mm_hg": 97.0,
      "five_year_risk_percent": 8.8,
      "horizon_months": 60,
      "immunosuppression_at_biopsy": false,
      "mest_e": 0,
      "mest_m": 1,
      "mest_s": 1,
      "mest_t": 0,
      "proteinuria_g_day": 1.1,
      "rasb_at_biopsy": true,
      "s0_5_year": 0.94176
    },
    {
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Barbour SJ, Coppo R, Zhang H, Liu ZH, Suzuki Y, Matsuzaki K, Katafuchi R, Er L, Espino-Hernandez G, Kim SJ, Reich HN, Cattran DC, Feehally J; International IgA Nephropathy Network",
        "doi": "10.1001/jamainternmed.2019.0600",
        "id": "barbour-2019-igan",
        "pmid": "30980653",
        "source": "JAMA Intern Med. 2019;179(7):942-952",
        "title": "Evaluating a new international risk-prediction tool in IgA nephropathy"
      },
      "formula": "igan_predict",
      "formula_expression": "LP = -0.320*(sqrt(egfr_ml_min_1_73m2) - 8.8) + 0.002*(map_mm_hg - 97) - 0.035*(ln(proteinuria_g_day) - 0.09) + 0.004*(map_mm_hg*ln(proteinuria_g_day) - 8.73) + 0.201*M1 - 0.035*E1 + 0.084*S1 + 0.700*T1 + 1.237*T2 + 0.101*T1*ln(proteinuria_g_day) - 0.321*T2*ln(proteinuria_g_day) - 0.017*(age_years - 38) + 0.118*RASB + 0.166*RASB*ln(proteinuria_g_day) - 0.266*immunosuppression; S0(t) = 1.0003754 - 0.1131641*u^2 + 0.0964763*u^2*ln(u), u = (t + 0.1)/100, t months; 5-year risk = 1 - S0(60)^exp(LP); Barbour 2019 eTable 3 full model without race/ethnicity only; M/E/S/T1/T2 RASB and immunosuppression are 0 or 1; natural log; caller supplies eGFR; not the race model; not KFRE",
      "age_years": 38,
      "linear_predictor": 0.4287,
      "egfr_ml_min_1_73m2": 77.0,
      "map_mm_hg": 97.0,
      "five_year_risk_percent": 8.8,
      "horizon_months": 60,
      "immunosuppression_at_biopsy": false,
      "mest_e": 0,
      "mest_m": 1,
      "mest_s": 1,
      "mest_t": 0,
      "proteinuria_g_day": 1.1,
      "rasb_at_biopsy": true,
      "s0_5_year": 0.94176
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Barbour SJ, Coppo R, Zhang H, Liu ZH, Suzuki Y, Matsuzaki K, Katafuchi R, Er L, Espino-Hernandez G, Kim SJ, Reich HN, Cattran DC, Feehally J; International IgA Nephropathy Network",
    "doi": "10.1001/jamainternmed.2019.0600",
    "id": "barbour-2019-igan",
    "pmid": "30980653",
    "source": "JAMA Intern Med. 2019;179(7):942-952",
    "title": "Evaluating a new international risk-prediction tool in IgA nephropathy"
  },
  "formula": "igan_predict",
  "formula_expression": "LP = -0.320*(sqrt(egfr_ml_min_1_73m2) - 8.8) + 0.002*(map_mm_hg - 97) - 0.035*(ln(proteinuria_g_day) - 0.09) + 0.004*(map_mm_hg*ln(proteinuria_g_day) - 8.73) + 0.201*M1 - 0.035*E1 + 0.084*S1 + 0.700*T1 + 1.237*T2 + 0.101*T1*ln(proteinuria_g_day) - 0.321*T2*ln(proteinuria_g_day) - 0.017*(age_years - 38) + 0.118*RASB + 0.166*RASB*ln(proteinuria_g_day) - 0.266*immunosuppression; S0(t) = 1.0003754 - 0.1131641*u^2 + 0.0964763*u^2*ln(u), u = (t + 0.1)/100, t months; 5-year risk = 1 - S0(60)^exp(LP); Barbour 2019 eTable 3 full model without race/ethnicity only; M/E/S/T1/T2 RASB and immunosuppression are 0 or 1; natural log; caller supplies eGFR; not the race model; not KFRE",
  "age_years": 38,
  "linear_predictor": 0.4287,
  "egfr_ml_min_1_73m2": 77.0,
  "map_mm_hg": 97.0,
  "five_year_risk_percent": 8.8,
  "horizon_months": 60,
  "immunosuppression_at_biopsy": false,
  "mest_e": 0,
  "mest_m": 1,
  "mest_s": 1,
  "mest_t": 0,
  "proteinuria_g_day": 1.1,
  "rasb_at_biopsy": true,
  "s0_5_year": 0.94176
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• KFRE — Compute 2-year and 5-year risk of kidney failure (dialysis or preemptive transplant) from the Tangri 2011 4-variable Kidney Failure Risk Equation (age, sex, eGFR, urine ACR).
• CKD-EPI 2021 eGFR — Compute race-free CKD-EPI 2021 creatinine eGFR in mL/min/1.73m2.
• KeGFR — Compute Chen 2013 kinetic eGFR (KeGFR) from two plasma creatinines, the hours between them, a caller-assigned steady-state creatinine and corresponding eGFR/CrCl, and MaxΔPCr/Day. magent does not compute MDRD or CKD-EPI.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
• exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.