Sunday, 11 June 2017

CPPERS, PPERS, LIPPERS or CLIPPERS?

There's a storm coming ...
A very interesting paper has recently appeared by Dr Taieb and colleagues about treatment strategies in CLIPPERS. I will return to this theme in a subsequent post but wanted to focus on something more basic, namely whether CLIPPERS is a single condition. In this recent works which reviews the majority of previously published cases, Dr Taieb proposes some division of CLIPPERS into sub-types. My reading of this is that it is a sub-division of convenience based on symptoms, investigations and response to treatment rather than any new insight into underlying biology. Nevertheless, it has been apparent for some time that there is immense variability under the CLIPPERS "umbrella".

Dr Taieb lists 5 key features of CLIPPERS which I paraphrase more simply here: (i) characteristic signs and symptoms, (ii) characteristic pattern of lesions seen in MRI, (iii) prompt response to steroid treatment, (iv) no competing diagnosis, (v) characteristic appearance of brain biopsy. So as a reminder, CLIPPERS stands for "Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids". With this in mind, Dr Taieb suggests that sufferers with a single attack and the first 4 or 5 key features are "PPERS" or "LIPPERS" respectively and sufferers with more than one attack and the first 4 or 5 key features are "CPPERS" or "CLIPPERS" respectively. 

I think the key interpretation of this system is that it is designed to reflect the available evidence about each case and make comparing cases easier. However it is influenced by the range of tests done (i.e. not everyone has brain biopsy) and the success of treatment. For instance, to date I have had a single attack and I declined a brain biopsy so I have the first 4 features and am "PPERS", but this can't distinguish between someone who has successful treatment and someone who simply has a disease that doesn't relapse.

In the diagnosis of Multiple Sclerosis, one of the criteria is that damage must have occurred at two different times - it is an inherently relapsing disease. However, presumably this is only true while effective treatments which could be given after a single episode are not available. I think the same is true of CLIPPERS and that when treatment strategies improve, the role of the "relapse" in diagnosis may dwindle.

(NOT A DOCTOR)

Read other articles in this series at Living With CLIPPERS.

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