MGUS(interpreting the test you didn’t order)

Family Medicine Review Course 2011Christian Cable, MD, FACP

The Case

What is the laboratory abnormality?

• 10-3 = 7

• What’s in there?

What comprises the blood?

What’s in blood . . .

• Cellular (bone marrow)

– RBCs– Platelets– WBCs

• Plasma (liver)

– Water– Proteins

• Albumin• Antibodies• Clotting factors

Proteins in the Blood?

Brainstorm

• As many “globins” as you can think of . . .

Tell me more about antibodies

What is the correct test?

SPEP/SIEP

• SPEP qualitative (is it there?)• SIEP quantitative (how much, which one?)

Copyright ©2001 American Society of Hematology. Copyright restrictions may apply.

Lazarchick, J. ASH Image Bank 2001;2001:100185

Figure 8. Immunofixation electrophoresis showing a monoclonal IgA lambda light chain restricted band

Gammopa-what?

Greek to me (I) . . .

• Gamma - - region in electrophoretic mobility• Pathy - - disease or condition

Greek to me (II) . . .

• Clonal - - type• Mono - - one• Poly - - many (much)

Differentiate Polyclonal from Monoclonal

“M-spike”

What is normal?

How high?

Polyclonal gammopathy - -significance

• Think of an elevated ESR• What could cause that?

Is polyclonal gammopathy a plasma cell disorder?

Monoclonal gammopathy - -determined significance

New Myeloma Classification

Copyright ©2002 American Society of Hematology. Copyright restrictions may apply.

Schrier, S. ASH Image Bank 2002;2002:100514

Figure 2. This is a bone marrow aspirate from a patient with multiple myeloma showing the abnormal accumulation of malignant plasma cells

Copyright ©2001 American Society of Hematology. Copyright restrictions may apply.

Lazarchick, J. ASH Image Bank 2001;2001:100185

Figure 11. Skull x-ray showing multiple lytic areas

Monoclonal gammopathy - -undetermined significance

Common?

• 3% of population over 50• twice that prevalence African Americans

Defined

• M-spike < 3 g/dL• absence of CRAB symptoms (at least those

attributable to MM) - - tricky with pre-existing renal disease!

• Bone Marrow involvement <10% with clonal plasma cells

How to evaluate

• CBC, Creatinine, Calcium, SPEP/SIEP• Skeletal survey (plain films)

When to refer

Higher risk

• non-Ig G (IgA & Ig M)• African American• total M spike: >1.5 g/dL

Why follow?

• Over 20 years: 1% per year turn into either Multiple Myeloma or another blood cancer

• Double that risk for non-IgG subtypes and African American patients

How do you follow it?

• I’d like to help follow higher risk patients.• Lower risk:

– re-test in 6 months then annually

Our Patient

SPEP

SIEP

1.6 g/dL IgA kappa

Recommendations

• referral• bone marrow biopsy

ccable@swmail.sw.org