Summary of the First European Primary hyperoxaluria (PH) Patient Meeting (2020) and Answers to the Questions received after the meeting

The first European PH Patient meeting was displayed virtually on September 19th 2020, and it was repeated almost entirely on October 11th 2020. PH Europe invited patients, families and professionals to join this up to date presentation on Primary Hyperoxaluria. The following topics were displayed as a video format via Zoom:

• Welcome to meeting and introduction of PH-Europe and PH&HP team
• Overview: The primary hyperoxalurias
• Primary hyperoxaluria type III: an update
• Diet in primary hyperoxaluria?
• Future perspectives of treatment for the Primary Hyperoxalurias
• Introduction of patient representatives from Pharma companies

Overall we were able to welcome 90 attendees in total from all over the world (Europe, USA, Pakistan, Brazil, Israel, Algeria) who could watch the presentations in six different languages (German, Spanish, French, Portuguese and Italian). We were also glad to welcome and get the support from OxalEurope (The European Hyperoxaluria consortium) and from the Oxalosis and Hyperoxaluria Foundation (OHF, USA).

After the meeting all patients had the possibility to send their questions either via chat or via email. Now, we present you here with the answers, also shown in six languages, aiming that all participants can obtain the same information.

We would like to send a special thank to Marcus Bauer (Animaniacs GmbH) for his IT support, to the Kindernierenzentrum in Bonn for hosting us, and to all the colleagues who helped us in translating and recording the videos.

And last, but not least, thank you to all of you who joined this initiative.

                                                                                                                                                              

Questions and answers to the First European PH Virtual meeting                                                                                     


PH TYPES

Q: Where can we find information about a known mutation type of PH1 that our child has, ie what was the progress of the kidney function reduction in children with the same mutation over the years.

A: There are scientific articles that describe genotype-phenotype correlations, however, they do not clearly put a given mutation to a given follow up. This is more information reported about an overall outcome to the whole PH1 community, and less according to the type of the mutation (missense, deletion). Also, as all types of PH are so heterogenous in clinical follow up, even in siblings with the same mutation, a prediction of follow up is not really possible yet.

WATER AND FOOD

Q: With vitamin B6, the 24 hr urine collections oxalate/creatinine are most of the times almost normal but when our child consumes more oxalate or maybe foods that naturally contains more salt in her diet it seems that increases … is it possible that some mutations of PH1 are more effected from the diet? Or it could be the salt?

A: In PH 1 patients we do not recommend too much dietary restrictions. We only let the patients know about the really high oxalate diets, like spinach, rhubarb or sweet potatoes. You will find extensive lists of oxalate content in diet, we would suggest to not really use that. It is more important to stick on a high fluid intake and alkaline citrate medication. Patients with PH3 are more prone to diet and this was shown in our presentations. We do not recommend salt reduction in PH patients with normal kidney function, but would do that in patients with chronic kidney disease.

Q: When the plasma Urea and uric acid in children with PH1 is high, should the protein in diet also be limited or use low protein products or substitutes that some companies produce ?

A: If the kidney function declines, blood urea may rise accordingly. When kidney function is significantly decreased, then protein intake may need to be decreased, but not because of oxalate, but because of the amount of blood urea (and possibly also because of uric acid). Here, products with low protein content can be used.

Q: By looking the tables of oxalate content on line ( Harvard, Uni of Pittsburg etc.) same foods are low in one table high in others (eg strawberry ) … which one should we follow ?

A: These differences are based on the time the fruits were harvested, for example, the oxalate content changes over the year and that is one other reason, why we do not recommend to stick on these lists!

NEW THERAPIES

Q: When RNA treatment starts, B6 and citrate as conservative methods are still necessary or may be stopped?

A: When RNAi treatment starts, first the other medication and the high fluid intake remain, but, when urinary oxalate excretion declined to (near) normal, these conservative measures can be reduced or finished.

Q: For glycolate there is no evidence that it causes problems to health but it seems that when the oxalate is reducing the glycolate increases (at least in our child’s case) is there a new medication that can also treat glycolate?

A: In PH 1 under the Lumasiran treatment, the glycolate levels increase, this is not the case under Nedosiran. However, to the best of our knowledge, the higher glycolate neither in urine nor in blood makes any problem.

Q: Are the new RNA treatments going to be covered from public insurance? Since most of the private health insurances do not cover genetic issues, we know that orphan drugs are very expansive if are not prescribed, Is there an estimated cost yet? Is there any case the European health cards could help have access in a country that medicines are approved when were we live are not approved yet ?

A: If the medication is getting a permission from the European Medical agency, then it should be available in Europe. However, there always are differences all over Europe for very expensive medication and thus they are not all available in every country.

OXALATE REDUCTION

Q: Our doctors say 76% less oxalate is huge. Fantastic. We think so too. Still, I ask myself how much damage 24% can do. Is that even an answerable question?

A: Every reduction over 50 % of urinary oxalate excretion is fantastic and it looks, as if the urinary oxalate is going further down in long term administration. So, the 76 % reduction leads to near normalization and this means, that this is a great achievement and should help, that a patient should no longer be on dire straits.

PH 3 AND KIDNEY FUNCTION

Q: Hi, noted in the presentation about PH3 that lower oxalate excretion levels were found ( if I have understood that correctly). I have had three 24hr oxalate excretions done and one was 1,500 a 1,950 and a 2,100. just wondered why mine are high in PH3? thanks

A: The data we had shown is the median data, so there are other PH III patients also, who have the same amount of oxalate excretion, as you have,

Q: Oh I see and does anyone know as I find this very confusing. I have been told that PH3 doesn’t usually cause ESRD or Oxalosis yet oxalate levels are just as high in my PH3 (and now others with PH3 as well) as PH1 and if I understand correctly, the high oxalate levels are what cause ESRD and oxalosis?

A: Yes, there is a paper saying, the higher the urine oxalate excretion, the worse the outcome. However, there is other not yet published data, which does not find this correlation. But, of course, with such a high oxalate in urine, the risk of getting into problems is high. However, long term follow up data is not available in PH 3 and hence, we cannot really predict the long term follow up in PH3 patients.

Q: Unfortunately I have been told I will end up in ESRD because I had a very late diagnosis which caused me to loose one kidney and severely damage my remaining one but this has been stressed this has been caused by my PH3 not being managed which allowed masses of stones to form and shut down one kidney and stretch and damage my remaining one. Obviously in the hope I get a new kidney in the future I still am baffled why I am excluded from ESRD and oxalosis from the PH3 itself when my oxalate excretion levels are very high like PH1. Is there something with PH3 that stops the oxalate from leaving the kidneys and causing oxalosis or causing ESRD even though the numbers are high?

A: We, the physicians taking care of PH patients, are putting data together to proof that also PH 3 patients are on risk of chronic kidney disease. We will fight to also make possible, that PH3 patients will get better treatment options. As said before, we are missing long term data in PH3, we need that urgently. Then we can help you better.

NEW DRUGS

Q: With this new drug if it would not go well, can you "go back to the previous treatment, without altering the values?

A: Of course, you can get back to the previous medication.                                                                                     

VITAMIN D AND B6

Q: I do have 1 question about Vit D. My daughter has a below optimal level of 23,10 ng/ml from last week routine check up. And this after summer time. How much should I give her during winter? Our family doctor says 2000/day. Shouldn't she reach 30?

A: You should please follow the local doctors advice.

Q: Also, what about B6?                                                                                                         

A: For your daughter type of PH (PH3), vitamin B6 is not helping. This is only a medication that is only efficient in a subgroup of patients with PH 1.

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