LPDs

Question 1

Monoclonal B cell lymphocytosis

Answer 1

Asymptomatic condition 

Presence of monoclonal B cell population   < 5 x 10^9/L

Absence of lymphadenopathy, organomegaly or any features diagnostic of another B cell LPD 

Question 2

Subtypes of MBLs

Answer 2

Low count MBL/clonal B-cell expansion: clonal B cell count <0.5x10^9/L and typically CLL/SLL phenotype  

CLL/SLL-type MBL: clinical B cell count >=0.5 x10^9/L and typical CLL/SLL phenotype  

Non-CLL/SLL MBL: any clonal B-cell expansion without the typically CLL/SLL phenotype  
- should trigger lymphoma staging investigation  

Question 3

Prognosis in MBLs

Answer 3

Note 10% of all blood donots above 65 years old have an MBL

High count MBL = >0.5x10^9/L
- Risk of prog is around 1-2% per annum
- Thought to be a continuum of CLL
- Studies suggest that prognostic markers in CLL

Low count MBL = <0.5 x 10^9/L
- 95% of MBL clones in the community are low counts MBL
- Almost never progresses and has actually been hypothesis as clinically distinct – different IgHV representation than high count
- Almost no progression to CLL there is increased risk of infection (and high mortality associated)