GI · LIVE

Los Angeles classification of oesophagitis

LA grading

Apply Lundell 1999 Table 1 Los Angeles classification of oesophagitis and return la_grade (none, A, B, C, or D) from four caller-assigned endoscopic flags.

LIVE $0.005 USDC GET /api/calc/la_grading

Markdown: /docs/la-grading.md · Canonical: https://magentlab.com/docs/la-grading

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

What it computes

Apply Lundell 1999 Table 1 Los Angeles classification of oesophagitis and return la_grade (none, A, B, C, or D) from four caller-assigned endoscopic flags.

When to use

When an agent already has endoscopic mucosal-break flags as assigned at endoscopy (presence of a mucosal break, longest break more than 5 mm, continuity between fold tops, and at least 75% circumference) and needs the published 1999 LA grade. magent does not interpret endoscopy images.

When not to use

Not a medical device.
Not a GERD diagnosis. magent does not diagnose gastro-oesophageal reflux disease.
The caller assigns the four endoscopic flags. magent does not interpret endoscopy images.
This tool is Lundell 1999 Table 1 Los Angeles classification only. Not Savary-Miller. Not Barrett or stricture grading (the paper records those separately). Not the 1994 proposed LA system (grade D was fully circumferential; 1999 changed D to at least 75% of circumference).
Absence of a mucosal break returns none. That is not a minimal changes grade; Lundell 1999 found those changes unreliable.

Formula

la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)

Citation

Title: Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification
Authors: Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L
Source: Gut. 1999;45(2):172-180
DOI: 10.1136/gut.45.2.172

Worked example

No mucosal break

Given: circumference_ge_75_percent=falsecontinuous_between_folds=falselongest_break_gt_5_mm=falsemucosal_break=false

mucosal_break is false (no mucosal break as assigned)
longest_break_gt_5_mm, continuous_between_folds, and circumference_ge_75_percent are required and false; they do not change the result
la_grade is none (no LA A-D; not minimal changes)

Mucosal breaks no longer than 5 mm, not between fold tops

Given: circumference_ge_75_percent=falsecontinuous_between_folds=falselongest_break_gt_5_mm=falsemucosal_break=true

mucosal_break is true
circumference_ge_75_percent is false (not D)
continuous_between_folds is false (not C)
longest_break_gt_5_mm is false (not B)
la_grade is A

Also searched as

Los Angeles classification
LA grade oesophagitis
Lundell 1999
Los Angeles esophagitis
LA classification A B C D
mucosal break oesophagitis
reflux oesophagitis LA grade
LA 1999 oesophagitis
Los Angeles grading

Try

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

/api/calc/la_grading?mucosal_break=false&longest_break_gt_5_mm=false&continuous_between_folds=false&circumference_ge_75_percent=false

Full URL: https://api.magentlab.com/api/calc/la_grading?mucosal_break=false&longest_break_gt_5_mm=false&continuous_between_folds=false&circumference_ge_75_percent=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/la_grading?mucosal_break=false&longest_break_gt_5_mm=false&continuous_between_folds=false&circumference_ge_75_percent=false"

Parameters

Name	Type	Required	Description
`mucosal_break`	boolean	required	One or more mucosal breaks present, as assigned by the caller. Lundell 1999 defines a mucosal break as an area of slough or erythema with a discrete line of demarcation from adjacent more normal-looking mucosa. true or false. If false, la_grade is none (no LA A-D; not minimal changes). magent does not interpret endoscopy images.
`longest_break_gt_5_mm`	boolean	required	Longest mucosal break more than 5 mm long, as assigned by the caller (Lundell 1999 Table 1 grade B vs A). true or false. Required even when mucosal_break is false (does not change none). magent does not measure lesions.
`continuous_between_folds`	boolean	required	A mucosal break is continuous between the tops of two or more mucosal folds, as assigned by the caller (Lundell 1999 Table 1 grade C). true or false. Required even when mucosal_break is false (does not change none). magent does not interpret endoscopy images.
`circumference_ge_75_percent`	boolean	required	Mucosal break(s) involve at least 75% of the oesophageal circumference, as assigned by the caller (Lundell 1999 Table 1 grade D; the 1999 revision, not the 1994 fully circumferential proposal). true or false. Required even when mucosal_break is false (does not change none). magent does not interpret endoscopy images.

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/la_grading 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": [
    {
      "circumference_ge_75_percent": "false",
      "continuous_between_folds": "false",
      "longest_break_gt_5_mm": "false",
      "mucosal_break": "false"
    },
    {
      "circumference_ge_75_percent": "false",
      "continuous_between_folds": "false",
      "longest_break_gt_5_mm": "false",
      "mucosal_break": "false"
    }
  ]
}

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/la_grading",
  "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": "Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L",
        "doi": "10.1136/gut.45.2.172",
        "id": "lundell-1999",
        "pmid": "10403727",
        "source": "Gut. 1999;45(2):172-180",
        "title": "Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification"
      },
      "formula": "la_grading",
      "formula_expression": "la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)",
      "criteria": [
        {
          "factor": "mucosal_break",
          "met": false
        },
        {
          "factor": "longest_break_gt_5_mm",
          "met": false
        },
        {
          "factor": "continuous_between_folds",
          "met": false
        },
        {
          "factor": "circumference_ge_75_percent",
          "met": false
        },
        {
          "factor": "none",
          "met": true
        },
        {
          "factor": "A",
          "met": false
        },
        {
          "factor": "B",
          "met": false
        },
        {
          "factor": "C",
          "met": false
        },
        {
          "factor": "D",
          "met": false
        }
      ],
      "la_grade": "none"
    },
    {
      "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": "Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L",
        "doi": "10.1136/gut.45.2.172",
        "id": "lundell-1999",
        "pmid": "10403727",
        "source": "Gut. 1999;45(2):172-180",
        "title": "Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification"
      },
      "formula": "la_grading",
      "formula_expression": "la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)",
      "criteria": [
        {
          "factor": "mucosal_break",
          "met": false
        },
        {
          "factor": "longest_break_gt_5_mm",
          "met": false
        },
        {
          "factor": "continuous_between_folds",
          "met": false
        },
        {
          "factor": "circumference_ge_75_percent",
          "met": false
        },
        {
          "factor": "none",
          "met": true
        },
        {
          "factor": "A",
          "met": false
        },
        {
          "factor": "B",
          "met": false
        },
        {
          "factor": "C",
          "met": false
        },
        {
          "factor": "D",
          "met": false
        }
      ],
      "la_grade": "none"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	la_grading
`formula_expression`	string	Published Lundell 1999 Table 1 Los Angeles classification rule
`la_grade`	string	none, A, B, C, or D. none if no mucosal break; D if break(s) involve at least 75% of circumference; C if continuous between fold tops but less than 75%; B if longest break more than 5 mm and not between fold tops; A if break(s) no longer than 5 mm and not between fold tops. Not a GERD diagnosis.
`criteria`	array	Per-factor rows with factor and met for the four caller-assigned flags and exclusive grades none, A, B, C, D; exactly one grade row is met
`citation`	object	Lundell 1999 Gut citation
`disclaimer`	string	Not-a-device notice

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": "Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L",
    "doi": "10.1136/gut.45.2.172",
    "id": "lundell-1999",
    "pmid": "10403727",
    "source": "Gut. 1999;45(2):172-180",
    "title": "Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification"
  },
  "formula": "la_grading",
  "formula_expression": "la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)",
  "criteria": [
    {
      "factor": "mucosal_break",
      "met": false
    },
    {
      "factor": "longest_break_gt_5_mm",
      "met": false
    },
    {
      "factor": "continuous_between_folds",
      "met": false
    },
    {
      "factor": "circumference_ge_75_percent",
      "met": false
    },
    {
      "factor": "none",
      "met": true
    },
    {
      "factor": "A",
      "met": false
    },
    {
      "factor": "B",
      "met": false
    },
    {
      "factor": "C",
      "met": false
    },
    {
      "factor": "D",
      "met": false
    }
  ],
  "la_grade": "none"
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

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Rome IV FD — Apply the Stanghellini 2016 Rome IV B1 functional dyspepsia criteria and return whether PDS (B1a), EPS (B1b), and the published FD box hold (rome_iv_fd).
Travis criteria — Apply the Travis 1996 day-3 of intravenous corticosteroids rule for severe ulcerative colitis and return travis_high from stools_per_day and crp_mg_l.

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.