Purpose

Define user requirements for a standalone FUZKK utility that accepts laboratory CSV data, evaluates the records using limits embedded in code, and produces LabWare-compatible JSON.

Scope

The utility is intended for preliminary QC/QA review, integration testing, LIMS/LabWare flow and evidence-trail preparation. Final release decisions remain under the laboratory's validated procedure and responsible personnel.

Users

QC analyst, QA reviewer, CSV/validation engineer, LIMS/LabWare integration engineer, responsible laboratory specialist.

User requirements

1. The utility shall run without arguments and print its self-description, a built-in input.csv example from GetDemoData(), and demo evaluation for the embedded records.
2. The utility shall run with two arguments: input.csv output.json.
3. The utility shall not read input.csv and shall not write output.json when started without arguments.
4. CSV numeric values shall be parsed using CultureInfo.InvariantCulture.
5. Output shall be generated as LabWare-compatible JSON with Header, Samples, Results, Status, StatusCode, ErrorMessage, Description and DescriptionEN.
6. For PASS records, ErrorMessage shall be an empty string.
7. Embedded limits shall follow this priority: Ph. Eur. → British Pharmacopoeia / UK implementation → EAEU / regional requirements → EMA/ICH/EU guidance → USP fallback.
8. If an exact monograph is not known, strict standard API limits are used where applicable: assay 98–102%, total impurities ≤1.0%, individual impurity ≤0.5%.
9. For biologics and mAb-like products, aggregation, sterility and endotoxin checks shall be included where relevant to the utility purpose.
10. If a parameter may arrive in different units, the unit shall be represented as a separate input field or explicitly reflected in the input.csv field name.

Input CSV

BatchNumber,ProductName,FcRn_Binding_Affinity_Kd_nM,FcGammaRIIIa_Binding_EC50,Galactosylation_Percent,Sialylation_Percent,Afucosylation_Percent,ADCC_Activity_Percent,CDC_Activity_Percent,Standard_FcRn_Kd
PLASMA-Fc-2026-001,IVIG 10% Liquid,250.0,15.0,45.0,12.0,2.0,95.0,98.0,240.0
PLASMA-Fc-2026-002,Subcutaneous Ig 16%,260.0,16.0,42.0,11.0,2.5,92.0,95.0,240.0
PLASMA-Fc-2026-003,Hyperimmune Ig,245.0,14.0,48.0,13.0,1.8,98.0,102.0,240.0

input.csv fields

Utility description

Fc Function Effector Assay Checker — Plasma Product Fc Effector Function Analyzer

Fc Function Effector Assay Checker — Plasma Product Fc Effector Function Analyzer

ℹ️ Utility evaluates Fc-region functionality of immunoglobulins:
• FcRn binding (half-life)
• ADCC activity (cellular cytotoxicity)
• CDC activity (complement-dependent cytotoxicity)
• Glycosylation profile (Galactose/Sialic acid)

⚠️ CRITICAL: Changes in glycans alter mechanism of action!
Low sialylation reduces anti-inflammatory effect of IVIG.

Usage:
FcFunctionEffectorAssayChecker.exe → demo mode (console output)
FcFunctionEffectorAssayChecker.exe input.csv output.json → evaluate your data

Input format:
BatchNumber,ProductName,FcRn_Binding_Affinity_Kd_nM,FcGammaRIIIa_Binding_EC50,Galactosylation_Percent,Sialylation_Percent,Afucosylation_Percent,ADCC_Activity_Percent,CDC_Activity_Percent,Standard_FcRn_Kd

Example:
PLASMA-Fc-2026-001,IVIG 10% Liquid,250.0,15.0,45.0,12.0,2.0,95.0,98.0,240.0

— WHY IS THIS NEEDED?
Fc function control is critical for IVIG and specific immunoglobulins (CSL, Grifols, Octapharma):
• Therapeutic effect of IVIG depends not only on antibody titer but also on ability to interact with immune system via Fc part
• FcRn binding determines how long product circulates in blood (T1/2)
• Glycosylation (especially terminal galactose and sialic acid) modulates inflammatory response
• ADCC and CDC are important for virus neutralization and pathogen clearance

⚠️ CRITICAL:
• FcRn affinity must match standard (±30%) for predictable pharmacokinetics
• ADCC/CDC activity 80-120% of standard guarantees efficacy
• Sialylation correlates with anti-inflammatory activity (mechanism of action in autoimmune diseases)
• Galactosylation is required for complement activation (CDC)
• Fractionation process must not damage Fc-region or alter glycan profile

Key features:
• Comprehensive assessment of Fc-fragment biological activity
• Structure (glycans) and function (ADCC/CDC) correlation
• Half-life control via FcRn
• Support for various immunoglobulin types

Critical parameters:
• FcRn Kd: Within 30% of standard
• ADCC: 80–120%
• CDC: 80–120%
• Galactosylation: Target ±5%
• Sialylation: Target ±5%

💡 Usage tips:
1. Use cell lines expressing human Fc receptors (NK cells for ADCC)
2. SPR (Surface Plasmon Resonance) gives most accurate FcRn affinity data
3. Control glycan profile by HILIC-UPLC or mass spectrometry
4. Compare new batches with reference standard that passed clinical trials
5. If low sialylation observed, check storage conditions and product pH

⚠️ Note: Unlike chemical tests, Fc functionality is an integral quality indicator. Even if protein is chemically pure, damage to Fc-region or glycan changes during production can make product ineffective for treating immunodeficiencies or autoimmune diseases.

Traceability and limitations

• The URS is used as the source document for functional specification, CSV review and later validation work.
• This document does not replace an approved pharmacopoeial monograph, validated analytical method or internal product specification.
• For product-specific limits, the approved customer specification takes priority.

The functional specification describes the behaviour of the standalone FUZKK console utility, input-data format, evaluation algorithm and output JSON structure.

Functional flow

1. Main() checks the number of arguments.
2. If no arguments are provided: PrintHello() prints the description and built-in input.csv example, then RunDemoEvaluation() executes Evaluate() over GetDemoData() and prints demo JSON.
3. If two arguments are provided: RunWithFiles(input.csv, output.json) reads CSV, evaluates each record and writes LabWare-compatible JSON.
4. LoadData() uses CultureInfo.InvariantCulture and shall not be called in no-arguments mode.
5. Evaluate() returns a named tuple with BatchNumber, ProductName, Parameters, CriticalFailCount, WarningCount, Recommendation and RecommendationEN.
6. GetIssues() builds messages for ErrorMessage in WARNING/FAIL cases.

Evaluation rules

• PASS: CriticalFailCount = 0 and WarningCount = 0.
• WARNING: CriticalFailCount = 0 and WarningCount > 0.
• FAIL: CriticalFailCount > 0.
• ERROR: exception during reading or processing.
• ErrorMessage remains empty for PASS.
• Limits are embedded in Program.cs; no external limit configuration is required.

Input and fields

BatchNumber,ProductName,FcRn_Binding_Affinity_Kd_nM,FcGammaRIIIa_Binding_EC50,Galactosylation_Percent,Sialylation_Percent,Afucosylation_Percent,ADCC_Activity_Percent,CDC_Activity_Percent,Standard_FcRn_Kd
PLASMA-Fc-2026-001,IVIG 10% Liquid,250.0,15.0,45.0,12.0,2.0,95.0,98.0,240.0
PLASMA-Fc-2026-002,Subcutaneous Ig 16%,260.0,16.0,42.0,11.0,2.5,92.0,95.0,240.0
PLASMA-Fc-2026-003,Hyperimmune Ig,245.0,14.0,48.0,13.0,1.8,98.0,102.0,240.0

Output JSON

{
  "Header": {
    "UtilityName": "Fc_Function_Effector_Assay_Checker",
    "Version": "1.0.0",
    "Timestamp": "UTC",
    "InstrumentID": "FUZKK-QC-WORKSTATION",
    "OperatorID": "Admin"
  },
  "Samples": [
    {
      "SampleID": "from BatchNumber",
      "BatchNumber": "from CSV",
      "ProductName": "from CSV",
      "TestName": "utility-specific test",
      "AnalysisCode": "utility-specific code",
      "Status": "PASS | WARNING | FAIL | ERROR",
      "StatusCode": "1 | 2 | 0 | -1",
      "ErrorMessage": "",
      "Description": "Russian recommendation",
      "DescriptionEN": "English recommendation",
      "Results": [
        {
          "ParameterName": "parameter",
          "ResultValue": 0.0,
          "UnitOfMeasure": "unit",
          "SpecificationLimit": "limit",
          "IsWithinSpec": true
        }
      ]
    }
  ]
}