Testing for CVID in Children

[supersub70]

I've been treated for CVID for about eight years now and last year we had the very happy event of the birth of our first child. He's nearly one now but I'm worried that he seems to pick up everything going around and is already on his 4th or 5th lot of antibiotics for various infections including chest and tonsilitus.

I know his immune system is still developing and its perfectly normal for youngsters to get all sorts of illnesses when they are this young, but should he really have this many? His Mum says none of the other kids in his playgroup have this many infections etc. I'm guessing that there is a minimum age they can test for PID in children because their immune systems are not fully developed yet?

I spoke to my immunologist about it before he was born and he said it was extremely unlikely that I'd pass it on to any offspring and to just enjoy parenthood.

Just looking for reassurances or anyone with a similar story. I'm probably being paranoid but his Grandparents are starting to worry he's got what I've got and although she doesn't admit it I know his Mum is thinking that too!

[gilliem]

Hi. I have CVID and haven't passed it to either of my daughters. However, the elder has low IgA and takes prophylactic penicillin all the time. Her deficiency was picked up by my immunologist when I was diagnosed. Bearing in mind that IgA is our first line-of-defence against infection, present in all our mucous membranes from nose to anus, it's possible that your son is low on IgA like Philippa. As a child, she specialised in spectacularly virulent bouts of tonsillitis! Don't fret about this, even if it does turn out that your son's IgA deficient. It's completely manageable and there's no reason to think that he'll ever develop full-blown CVID. If your family's worried, remind them that quite a percentage of the whole population 's IgA deficient and never knows it! Give your son time to do some growing and to develop his own immune system. Monitor the situation, and I strongly suggest a written record, so that if you ever have to go to your own immunologist and ask for advice, you'll have facts, figures and dates to quote.
Best wishes,
Gillie.
PS. Philippa's first baby will be born in about 5 months time, so she and her husband aren't too worried!

[liz2mac]

Hi, the current understanding is that all primary antibody deficiencies are caused by some kind of genetic defect but in the case of cvid they don't know what the defect is or how it is transferred. Experience shows that it's incredibly rare for a parent with cvid to pass full blown cvid on to their children, however we do often have children who are more sickly than other kids. Some of these turn out to have IgA deficiency, some have selective antibody deficiencies etc. Usually they need no more intervention than appropriate antibiotic therapy.

Sent from my GT-N7000 using proboards

[dianesistern]

Hi this is difficult for me to put as it might be seen as negative but i have cvid and so did my sister inherited from my dad i also have a cousin with it and i have three children all grown up now who have been tested the youngest one has a slight problem with her immunity, but the nagative bit is that i think all children should be tested as lack of diagnosis can cause more problems although my sister was an adult before she was diagnosed she had had many years of health problems and endedup getting encephalitis before being diagnosed so i am of course very pro testing everyone for cvid at the risk of being negative i feel forewarned is forarmed. Diane

[liz2mac]

Hi Diane,
You're right of course, some of us with cvid do pass on full blown cvid to our children. Its imperative that our children and grandchildren are tested as soon as they are old enough to make testing viable. I guess that should include our neices and nephews as well?
Liz

[s162216]

Its important to remember that CVID itself is actually a 'diagnosis of exclusion' and represents about 50 different primary immunodeficiencies that have the same similar clinical symptoms so some people may produce inert antibodies, others may have a T-helper cell defect or a defect in any stage of antibody production but in the end the outcome is usually similar. Basically if the person has B-cells then its not XLA, if CD40 levels are normal then its not a subtype of Hyper IgM syndrome and if clinical findings exclude all other diagnosis's then its CVID.

Because of this, there is not one exact genetic mutation for CVID and a 'cure' or test for one sub-type may benefit some but not the majority. At the moment only 6 mutations for 6 sub-types have actually been identified and these have all been in rare cases where only 1 or a few people have the mutation. To sequence the genome of everyone with CVID would be prohibitively expensive with todays technology ($100,000+ per person) and take a long time so its not viable as a diagnosis tool.

Because CVID is a collection of different mutations, some are recessive and others dominant. In the case of dominant mutations, only one parent needs to have the condition for it to be passed on, with a 50% chance of a child having it or being normal. With recessive mutations though, there is usually a 25% chance of being affected or normal and a 50% chance of being a carrier. The problem is when 2 carriers have offspring as recessive genes are not usually passed on. It should be remembered that there are many types of CVID and as so many different types of mutation and the mutations of the parents have to be similar in the case of recessive genes for it to be passed on so in the end the chances are fairly small but it does happen. As so testing beyond direct family (parents, children etc) is pretty unnecessary and testing every child would simply not work as every childs immune system develops differently and starts to produce its own antibodies around 6 months of age when the maternal IgG starts to become low. In the case of other PIDs though with distinct mutations (especially SCID) it is feasible and some countries include these in the post birth tests.

Sam

[liz2mac]

Hi Sam,
Whilst all you say is scientifically sound, trying to put it in laymans terms, the fact is is that nobody yet knows what the genetic defects are in CVID. As you say, CVID is actually a description of many types of Primary Antibody Deficiency. See the website for the definition of what CVID means. To re-iterate about testing children whose family members have CVID, my understanding of the age when testing becomes appropriate is at between 3 & 4 years old. Since the tests for CVID are so cheap, it is financially worth testing IF there is a concern. Whether it is ethical to put a child through the trauma of a blood test when they are showing no signs of problems is somthing for parents and Dr's to discuss and decide on together. My Grandchildren were tested because that is hwat their parents decided to do. Only one of the four so far shows any signs of problems. However, my daughter went undiagnosed until she was 29 with a specific antibody deficiency because I didn't recognise it. We're not always the best ones to notice problems in our own children!!
Liz

[dianesistern]

As i am about to be a grandmother i feel it slightly alarming that they are taking no notice of the family history with us and not intending to look into testing my soon to be grandson as her mum could be a carrier

[liz2mac]

Diane,
Please don't worry about this at the moment, Keep putting pressure on me and I'll remember to ask our medical advisory panel to write a leaflet about the testing of children when a family member has a PAD or other PID. I'm drowning slightly in UKPIPS work and wil be until the end of November. BUT, keep reminding me everyone. If anyone else is interested in working on the leaflet production system (from your own homes) as a UKPIPS Volunteer, please let me know.
Liz

[beckag87]

Hi Liz,

I will help with this Will be in touch tomorrow/today?! (Saturday).

Speak to you soon,

Becks

[liz2mac]

Thank you Becks.
Liz