IgG IEFDiagnosing Multiple Sclerosis
Multiple Sclerosis• CNS disorder• Scar formation on outside of
nerve cells of brain and spinal cord
• Inflammation destroys covering of nerve cells leaving scar tissue
• Nerve cells cannot transmit impulses
Prevalence• Onset at age 15 to 50 years• 70% female• Temperate climate predominant
Symptoms• Optic neuritis• Numbness / weakness in
extremities• Instability in walking• Tremors• Loss of bladder control• Heat intolerance• Fatigue
Diagnosis by Exclusion• Encephalitis• CNS Vasculitis• Lyme Disease• Behet Syndrome• Sarcoidosis• Syphilis• Leukodystrophies
• Lupus Erythematosus• Spastic Paraparesis• Vitamin B-12 Deficiency• Sjogren’s Syndrome• Hereditary Degenerative
Disorder• Multifocal
Leukoencephalopathy
Criteria for DiagnosisHistory of two attacks with positive oligoclonal bands
or increased IgG in CSF
Criteria for DiagnosisHistory of two attacks with no laboratory abnormality
Criteria for DiagnosisHistory of two attacks with
clinical and paraclinical evidence of lesions, oligoclonal bands, and
increased IgG in CSF
Criteria for DiagnosisHistory of two attacks with
clinical evidence of at least one lesion, and clinical or paraclinical
evidence of another lesion
IEF Theory• Stable pH gradient with carrier
ampholytes in an electrical field
IEF Theory• Stable pH gradient with carrier
ampholytes in an electrical field• Proteins exhibit net + or – charge
IEF Theory• Stable pH gradient with carrier
ampholytes in an electrical field• Proteins exhibit net + or – charge• Migrate toward electrode of
opposite charge
IEF Theory• Stable pH gradient with carrier
ampholytes in an electrical field• Proteins exhibit net + or – charge• Migrate toward electrode of
opposite charge• Rate of migration ↓ as it reaches
isoelectric point
IEF Theory• Stable pH gradient with carrier
ampholytes in an electrical field• Proteins exhibit net + or – charge• Migrate toward electrode of
opposite charge• Rate of migration ↓ as it reaches
isoelectric point (pI)• Protein focuses at pI
IEF Theory• Stable pH gradient with carrier
ampholytes in an electrical field• Proteins exhibit net + or – charge• Migrate toward electrode of
opposite charge• Rate of migration ↓ as it reaches
isoelectric point (pI)• Protein focuses at pI; some drift
but regains charge and migrates back
IEF ProcedureStep 1: Focus proteins
IEF ProcedureStep 2: Transfer proteins to
nitrocellulose membrane
IEF ProcedureStep 3: React with IgG antisera
IEF ProcedureStep 4: React with chromagen Step 5: Air dry
Total Time: 2.5 to 3.0 hours
Interpretation
Compare CSF and Serum
Looking for intrathecal synthesisindicated by
oligoclonal bands in CSF but not in serum
Interpretation
Negative – no oligoclonal bands in CSF
Interpretation
Mirror Image – same bands in CSF and serum
Interpretation
Positive – Oligoclonal bands in CSF but not in serum
Interpretation
Positive oligoclonal banding is not diagnosis of MS
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