IgG IEF

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