jamunjar-logo
whatsapp
cartmembermenu
Search for
"test & packages"
"physiotherapy"
"heart"
"lungs"
"diabetes"
"kidney"
"liver"
"cancer"
"thyroid"
"bones"
"fever"
"vitamin"
"iron"
"HTN"

IgG 4 Sub class

Blood
image

Report in 48Hrs

image

At Home

nofastingrequire

No Fasting Required

Details

Measures IgG4 levels.

₹7,548₹10,783

30% OFF

IgG 4 Subclass Test Guide

  • Why is it done?
    • Measures serum IgG 4 antibody levels, a specific immunoglobulin G subclass involved in immune responses
    • Diagnoses IgG 4-related disease (IgG4-RD), a systemic fibroinflammatory condition affecting multiple organ systems
    • Evaluates autoimmune pancreatitis (type 1), the most common form associated with elevated IgG 4 levels
    • Investigates chronic sclerosing conditions affecting salivary glands, lacrimal glands, and bile ducts
    • Monitors response to immunosuppressive therapy in confirmed IgG4-RD cases
    • Assesses patients with persistent lymphadenopathy or mass lesions of unknown etiology
    • Performed when clinical presentation suggests IgG4-RD or when other autoimmune diagnoses have been ruled out
  • Normal Range
    • Normal Reference Range: 4-86 mg/dL (40-860 mg/L) in adults; varies slightly by laboratory
    • Units of Measurement: mg/dL (milligrams per deciliter) or mg/L (milligrams per liter)
    • Normal Result: IgG 4 levels within laboratory reference range indicate absence of IgG4-RD; typically comprises 3-4% of total IgG
    • Elevated Result: IgG 4 >135 mg/dL (>1350 mg/L) is considered significantly elevated; levels >200 mg/dL strongly suggest IgG4-RD
    • Borderline Values: IgG 4 levels between 86-135 mg/dL require clinical correlation and may warrant repeat testing
    • IgG 4/Total IgG Ratio: >40% indicates increased IgG 4 proportion; normal ratio is <4%; elevated ratio supports IgG4-RD diagnosis
    • Note: Normal IgG 4 levels do not completely exclude IgG4-RD; diagnosis requires clinical, serological, and histological correlation
  • Interpretation
    • Moderately Elevated (86-135 mg/dL): May suggest early IgG4-RD or other conditions; requires correlation with clinical symptoms, imaging findings, and histopathology
    • Markedly Elevated (>135 mg/dL): Consistent with IgG4-RD diagnosis, particularly when IgG 4/total IgG ratio >40%; higher levels correlate with disease activity
    • Very High Levels (>200 mg/dL): Strongly indicative of active IgG4-RD; associated with multi-organ involvement and potential disease complications
    • IgG 4/Total IgG Ratio Interpretation: Ratio >40% strengthens IgG4-RD diagnosis; ratio <40% with elevated absolute IgG 4 suggests other etiologies
    • Factors Affecting Results: Active infection (viral, bacterial), other autoimmune conditions, malignancies, immunosuppressive therapy effects, and specific immunizations can influence IgG 4 levels
    • Longitudinal Monitoring: Decreasing IgG 4 levels during treatment indicate therapeutic response; persistent elevation suggests inadequate disease control
    • Clinical Significance: Elevated IgG 4 combined with characteristic histology (IgG 4-positive plasma cell infiltration >10 cells/HPF) confirms IgG4-RD diagnosis
    • Negative Result Does Not Exclude Disease: Up to 30% of biopsy-proven IgG4-RD patients may have normal serum IgG 4 levels; localized disease may show normal systemic levels
  • Associated Organs
    • Pancreas: Type 1 autoimmune pancreatitis most commonly associated with IgG4-RD; can lead to pancreatic insufficiency and diabetes mellitus
    • Salivary Glands: Chronic sclerosing sialadenitis affecting submandibular and parotid glands; presents with xerostomia and recurrent infections
    • Lacrimal Glands: IgG4-RD involvement causes chronic sclerosing dacryoadenitis leading to dry eye (xerophthalmia) and visual complications
    • Biliary System: IgG4-associated cholangitis and sclerosing cholangitis affecting common bile duct and intrahepatic ducts; risk of biliary strictures and cholangiocarcinoma
    • Lymph Nodes: Generalized lymphadenopathy with IgG4-positive plasma cell infiltration; can mimic lymphoma
    • Retroperitoneum: Retroperitoneal fibrosis causes chronic inflammation; may present with abdominal or back pain and potential ureteral obstruction
    • Mediastinum: Mediastinal fibrosis and mass formation; may involve lungs with pulmonary nodules or interstitial lung disease
    • Kidney: IgG4-associated nephropathy with tubulointerstitial nephritis; may progress to chronic kidney disease if untreated
    • Vascular System: Large vessel vasculitis affecting aorta and branch vessels; risk of aortic aneurysm formation and dissection
    • Associated Complications: Organ dysfunction from fibrosis, increased malignancy risk (particularly pancreatic cancer), and potential life-threatening vascular complications if disease progression not controlled
  • Follow-up Tests
    • Tissue Biopsy (Histopathology): Essential for confirming IgG4-RD diagnosis; demonstrates IgG 4-positive plasma cells >10 cells/high-power field and IgG 4/IgG ratio >40%
    • Imaging Studies: CT or MRI of affected organs to assess extent of fibrosis, mass formation, and organ involvement; baseline imaging for disease monitoring
    • Total IgG and IgG Subclasses: Measure total IgG and calculate IgG 4/total IgG ratio for diagnostic confirmation; assess other IgG subclasses
    • Complete Blood Count (CBC): Monitor for lymphocytosis, thrombocytopenia, or anemia associated with systemic disease
    • Comprehensive Metabolic Panel: Assess liver function, kidney function, and electrolytes; critical for monitoring organ involvement and therapy effects
    • Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP): Markers of systemic inflammation; useful for monitoring disease activity during treatment
    • Autoimmune Markers: Antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA), and rheumatoid factor to exclude other autoimmune conditions
    • Organ-Specific Tests: Pancreatic enzymes (amylase, lipase), liver function tests, chest imaging if respiratory involvement suspected
    • Periodic IgG 4 Monitoring: Repeat testing at 3-6 month intervals during initial treatment phase to assess therapeutic response
    • Maintenance Monitoring: Annual or biannual IgG 4 levels during maintenance therapy; more frequent if clinical deterioration suspected
    • Malignancy Screening: Regular surveillance imaging and tumor markers given increased cancer risk associated with IgG4-RD, particularly pancreatic adenocarcinoma
  • Fasting Required?
    • Fasting Requirement: No
    • The IgG 4 subclass test does not require fasting; serum IgG 4 levels are not affected by food intake or recent meals
    • Patient can eat and drink normally before the test; no dietary restrictions are necessary
    • Medications: May be taken as usual; most medications do not interfere with IgG 4 measurement; inform phlebotomist of current immunosuppressive therapy
    • Recent Immunizations: Inform healthcare provider if immunization received within 1-2 weeks; may temporarily elevate immunoglobulin levels
    • Sample Collection: Blood sample collected via venipuncture into serum separator tube (SST) or appropriate tube per laboratory protocol
    • Timing Considerations: Test can be performed at any time of day; no specific time restriction exists
    • Hydration: Normal hydration recommended; severely dehydrated patients may have artificially elevated immunoglobulin levels
    • Active Infection: Ideally, test should be performed when acute infection not present, as active infection may transiently elevate IgG 4 levels

How our test process works!

customers
customers