Thiopurine Metabolites

[DustyKat]

Received Matt’s results last week and would appreciate anyones thoughts:

Matt is on 100mg of Imuran (has been so for close to 3 years now) and at the time of testing was on Pentasa 1grm daily -

TGN 885

6MMP 1130

Thanks

Dusty.

 

[Catherine]

My guess is overdosing and maybe 75 mg aza would be high enough.

Do your results have any notes?

 

[DustyKat]

My thoughts exactly Catherine.

The comments are only generalised ones regarding the issues that may arise when TGN is above 450 and 6MMP is above 5700.

His total WCC is normal, albeit at the lower end and all individual readings are normal except for lymphocytes. Lymphocytes have always sat below normal and have pretty much alternated between readings of 0.6 and 0.7 each blood draw.

The latest bloods have his lymphocytes at 0.5.

My questions, based on the above would be:

1. What part is the increased TGN having on the lymphocyte count?

2. What role, if any given the small dose, is Pentasa having on his increased TGN?

3. His lymphocytes have dropped further since commencing the Pentasa, is this of concern?

4. Should he have his Imuran dose reduced?
Going off a weight based dose, and that is the lower end of that equation at 2mg per kilo, he fits neatly with the 100mgs so he not being overdosed from that aspect of things.

Dusty. xxx

 

[Johnnysmom]

Johnny's GI said the therapuetic level can vary in individuals. Johnny has been sub-therapuetic for about a year now but the GI feels some people do well in those ranges. His WBC is usually between 4.4 and 5. Our GI felt comfortable with the lower dose because the fecal cal has been normal and he hasn't had any symptoms.

This is an article about the influence of 5ASAs on 6-TGN metabolite levels.

http://www.ncbi.nlm.nih.gov/pubmed/20590602

 

[Catherine]

Our GI says after we increased to 150mg that was working because the lymphocytes decreased.

http://www.healio.com/gastroenterol...6-a430-d735ef89a8d7}/how-do-you-monitor-patie

• What CBC and LFT blood results do you aim for?

The aim of therapy is immunomodulation without immunosuppression, and I aim for a total white cell count of greater than 3.5 x 109/L with a lymphocyte count greater than 1.0 x 109/L, or occasionally slightly lower. Asymptomatic elevations of hepatic transaminases only require dose reduction once they reach more than twice the upper limit of normal.