nbme 17? - jjespinal

[ArchivalUser]

4.A 60-year-old man comes to the physician for an examination prior to employment. Physical examination shows no abnormalities. Laboratory studies show :
Hemoglobin 14g/dl
Hematocrit 42%
Leukocyte count 12,000
Segmented neutrophils
Small lymphocytes 50%
Monocytes 5%
Platelet count 250,000 mm3
Flow cytometry analysis of peripheral lymphocytes shows the following phenotype:
CD3 50%
CD4 40%
CD8 10%
CD20 50%
Surface kappa 47%
Surface lambda 3%
Which of the following is most predictive of a clonal lymphoid proliferation in this patient?
A) Absolute CD3+ T-lymphocyte count
B) Absolute CD20+ B-lymphocyte count
C) Absolute lymphocyte count
D) CD4:CD8 ratio
E) Surface kappaurface lambda ratio
MM= E i need explanation

thanks in advance

[ArchivalUser]

Kappa lamda ratio 3:1(N). This tell you the polyclonal expansions means that all different types B cell are producing the antibodies. But in Mm only light chain is formi.e monoclonal so the ratio is 6:1(light chain). Cancer is always monoclonal expansion. Hopefully u can understand.

[ArchivalUser]

Each plasma cell produces EITHER kappa OR lamba light chains; not both.

Normally, you have a nice mix of both types floating around.

In multiple myeloma, one of your plasma cells became cancerous and started multiplying. As it replicated, it kept producing antibodies and the associated light chains, but ONLY ONE TYPE. This is what tips us off that something cancerous is going on.

Clinically, when we suspect a patient has MM we typically order:
1) serum protein electrophoresis
2) urine protein electrophoresis
3) serum free light chains

In MM, the SPEP (these commonly appear on step 1) will show a monoclonal spike, or a giant peak over "gamma" which suggests you're producing a ton of antibodies.

The SFLC, however, will clearly show a predominance of kappa or lambda. So far in the patients I've taken care of, the ratios weren't that important because one was VERY elevated compared to the other.

The UPEP will show bence jones proteinuria.

Step 1 loves this disease because it ties together pathology, immunology, oncology, etc.

A number of different chemotherapy regimens out there, but I could see step 1 asking about thalidomide which has made a comeback as a chemotherapeutic drug for MM.