Wednesday, February 17, 2010


There has been a recent report of Progressive Multifocal Leukoencephalopathy (PML) in three patients with CLL treated with rituximab, and this has aroused some alarm in patients. The paper by D'Souza et al at the William Beaumont Hospital, Royal Oak Michigan has been published electronically in the journal Clinical Lymphoma, Myeloma & Leukemia Volume 10 pp E1 to E9.

PML is a disease of the nervous system caused by a virus named after John Cunningham (the JC virus) which most people contract in early life but which lays dormant controlled by the immune system for the rest of their lives. It is reactivated when the immune system fails and spreads to the brain where it infects oligodendrocytes and to a lesser extent astrocytes. There is a failure to make myelin, the insulating material around nerve cells, leading to confusion, disorientation, personality changes, loss of speech and balance, dementia and death. There is no effective treatment.

Although the three patients reported had all been treated with rituximab, they were all severely immunosuppressed from other treatments: the first with long term chlorambucil and then fludarabine, the second with fludarabine and cyclophosphamide and the third with chlorambucil, fludarabine, alemtuzumab, pentastatin and cyclophosphamide. They had had CLL for respectively 3 years, 8 years and 9 years.

Although PML is most commonly associated these days with AIDS, where it occurs in between 3-5% of patients, it was originally recognized in hematologic cancers including CLL. Immunity to the JC virus resides in the T cells rather than antibody, and the T-cell depletion seen in CLL patients treated with fludarabine or Campath is comparable with that seen in AIDS.

In Bournemouth, despite seeing close to 1000 patients with CLL we have not seen PML. This contrasts strongly with Royal Oak, Michigan where these three cases were among only 45 cases of CLL seen by them. I don't think we are missing the diagnosis.

Inpatients who have transplants it is much more common to reactivate other dormant viruses like Herpes Zoster, CMV and EBV, but PML does occur. In CLL it is often unrecognized how immunodeficient patients who have longstanding CLL plus multiple treatments can be. It is this group who are most likely to succumb to PML. Patients who receive rituximab alone or as part of FCR first line are most unlikely to reactivate JC.


Anonymous said...

I saw the paper a while ago and investigated what happened to patients with PML. Many outright die, some survive, but with various neurological deficits.

Not a pretty picture. I wonder if the Michigan facility has done anything differently than other institutions.

Your report is reassuring to those newly diagnosed; less so those of us who have been fighting the disease for years.

I guess the lesson is to cure CLL with the first treatment.

This means treatment when the counts start to go out of control.

For me, I had seven years of steady counts, then something happened and the counts skyrocketed. That's when to treat (if not before), even if you feel OK, as I did. My CLL expert recommended treatment when he saw the numbers take off.

CLL CANADA said...

The only thing that the Michigan facility is doing and probably others in the U.S.A. is to treat CLL too aggressively and too often with FCR or Fludara or Rituxan.

In order to get PML your immune system must be nearly completely collapsed.

It is still very rare. The French study (1999) saw it effecting 0.52% of CLL patients

Also see the study in Blood about PML


Anonymous said...

Sorry, this has nothing to do with PML.I am a a 47 years old female and have just discovered in Sept 09that I have Cll. My problem is I can`t/don`t know of any specialists in Scotland to get a DNA prognosis etc done and I feel I`m in a third world country.
My doctor/heamotologist just keep saying it will be 10 to 20 years before I need treatment. How do they know this?

Terry Hamblin said...

They don't. I don't know of anywhere in Scotland that does these tests. Ask your haematologist.

Tricia said...

Is it possible to test for the latent JC virus before undergoing any further treatment?

Terry Hamblin said...

It is, but 99.9% of people are positive. It's not the presence of teh virus that matters, it's the state of your immune system. Even then we don't know how to measure that in any useful way for PML.

Anonymous said...

Dear Terry
I am a Brazilian 35 yr old male who has got the diagnosis of MBL two years ago. At that time monoclonal B lymphocytes count was 1777 (moderate expression of CD20;CD11c) with a total lymphocytes count of 4400. My haematologist told me to move on and undergo regular blood counts every year or so. Surprisingly my total lymphocytes count has dropped to 3200 after 6 months from the "diagnosis" and to 3000 last month.
I have two questions:
1 - Is it possible to occur (that drop in lymphocyte count)in MBL patients?
2 - Does MBL lead to such a damaged immune system as in CLL that viruses antibodies (HIV, Hepatitis, etc) would not be detected (false negative tests)?
Thank you and best wishes.

Terry Hamblin said...


The majority of patients with MBL never progress to CLL. It is certainly possible for lymphocyte counts to spontaneously decrease. No-one has done immunization studies in MBL.

Anonymous said...

My mother had CLL (so did her mother, and 2 aunts. Her grandmother had leukemia, I assume it was CLL, but not stated as such at the time of her death. My mother had Rituximab therapy and later developed PML (which was positively identified via a spinal tap at Mayo Clinic and later in an autopsy). This was a terrible disease that took away her sight, caused many, many hallucinations, and weakened her body so that she could no longer walk. She died weighing approx 70 pounds. The warning was not stated at the time she received this treatment, and if it had, the risk benefit analysis would never had existed. I will NEVER take this medicine.

Debra Andrews said...

My husband died of PML June 13, 2010 at 61. First symptom was bilateral vision loss in April 2009. PML is hell on earth.

He was diagnosed with CLL in 2003, and developed Hodgkins Lymphoma in ADDITION to CLL (found in liver) in June 2005. Treatments received were chlorambucil from March to June 2005, 9 months ABVD chemo for Hodgkins, Treanda for CLL in 2008 and Treanda again in 2010. His T-cell count was 200. It must be the compromised immune system that allows the JC Virus to reactivate and head to the brain to do its damage. Is there a way to raise the T-cell count?

Anonymous said...

My husband (57) has had a stem cell transplant in June and is now being tested for PML. he has developed weakness etc. What are the latest treatments or research?

Terry Hamblin said...

Alas, there is no effective treatment.

Anonymous said...

Does PML always follow a progressive course? Are there any common features that indicate the PML is in remission, and at what point could it be said that the disease is no longer active?

Terry Hamblin said...

I have never heard of it following other than a progressive course.