Guest guest Posted July 13, 2009 Report Share Posted July 13, 2009 I wonder if this might not be a good question to ask the folks at Genetech, the manufacturers. Maybe you could wtie to them at http://www.xolair.com/index.html to get some information. Best wishes on this. Please let us know what you hear. Mike McBride ________________________________ From: meagainbenny <meagainbenny@...> Sent: Monday, July 13, 2009 6:44:53 AM Subject: [ ] Xolair and Lyme test Hi All, I'm a bit confused here and was hoping maybe someone knew something that could help me out. Back in early May, I was bitten by a tick, my MD did a 'Lyme test' 4 weeks out and 6 weeks out and they both came back negative. Each of the blood tests have been done at my PCP's office right after my bi-weekly Xolair appointments. I have all or most of the symptoms of Lyme Disease (night sweats, joint pain/swelling, etc...) so it has been perplexing as to why the tests are negative. I made an appointment with an Infectious Disease doctor who specializes in Lyme cases, so today when I got my Xolair, I got copies of the blood work to give to this new doctor. The blood work says that the Lyme tests are based on levels of IgG antibodies. So my question is, would Xolair block those antibodies and thus the test would be negative? I did some research online, but this is such an obscure thing, the answer doesn't seem to be readily available. Thank you for any help you can give me, Meagan Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 13, 2009 Report Share Posted July 13, 2009 This is a good thought, but is overall not a concern. Xolair does not bind out IgG. Xolair is an IgG molecule, which binds IgE molecules only (on average a 2:1 ratio of omalizumab:IgE). It is engineered to be that specific. So, to draw comparison, your IgG antibodies are not affected by omalizumab. Another question that will come up is " because omalizumab is an IgG antibody will it interfere with the results of an IgG test? " the answer is invariably, no. The reason for this is because IgG antibodies circulate in our blood at relatively high concentrations - the highest of all our antibodies. IgG exists as 660-1350 mg/dL as an average range. So, in an average adult's blood, the total IgG amount would probably range from 18 to 39 grams (or 18,000 to 39,000 mg). Omalizumab, at the highest dose is 375 mg (or 0.375 grams) at any one time. So, as you can see the addition of omalizumab to the current amount of IgG is negligible. Furthermore, most of the omalizumab is bound to IgE, and thus is far less than the original 375 mg floating around freely in the blood. on top of all this, there is no reported literature that discusses the interference of omalizumab on IgG testing, nor anything with Lyme disease. So some reassurance there. Lyme disease is a very tricky disease. there is no one test that will conclusively give you an indication one way or the other. Glenn - Pharm.D. > > I wonder if this might not be a good question to ask the folks at Genetech, the manufacturers. Maybe you could wtie to them at http://www.xolair.com/index.html to get some information. Best wishes on this. Please let us know what you hear. > Mike McBride > > > > > > > ________________________________ > From: meagainbenny <meagainbenny@...> > > Sent: Monday, July 13, 2009 6:44:53 AM > Subject: [ ] Xolair and Lyme test > > > > > > Hi All, > > I'm a bit confused here and was hoping maybe someone knew something that could help me out. Back in early May, I was bitten by a tick, my MD did a 'Lyme test' 4 weeks out and 6 weeks out and they both came back negative. Each of the blood tests have been done at my PCP's office right after my bi-weekly Xolair appointments. I have all or most of the symptoms of Lyme Disease (night sweats, joint pain/swelling, etc...) so it has been perplexing as to why the tests are negative. I made an appointment with an Infectious Disease doctor who specializes in Lyme cases, so today when I got my Xolair, I got copies of the blood work to give to this new doctor. The blood work says that the Lyme tests are based on levels of IgG antibodies. So my question is, would Xolair block those antibodies and thus the test would be negative? I did some research online, but this is such an obscure thing, the answer doesn't seem to be readily available. > > Thank you for any help you can give me, > Meagan > > > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 14, 2009 Report Share Posted July 14, 2009 hmmm I would think the Igg which xolair creates hangs around for awhile just like the bound Ige does thus there could be a very cumulative elevation. ________________________________ From: fpa9 <fpa9@...> Sent: Monday, July 13, 2009 4:21:52 PM Subject: [ ] Re: Xolair and Lyme test This is a good thought, but is overall not a concern. Xolair does not bind out IgG. Xolair is an IgG molecule, which binds IgE molecules only (on average a 2:1 ratio of omalizumab:IgE) . It is engineered to be that specific. So, to draw comparison, your IgG antibodies are not affected by omalizumab. Another question that will come up is " because omalizumab is an IgG antibody will it interfere with the results of an IgG test? " the answer is invariably, no. The reason for this is because IgG antibodies circulate in our blood at relatively high concentrations - the highest of all our antibodies. IgG exists as 660-1350 mg/dL as an average range. So, in an average adult's blood, the total IgG amount would probably range from 18 to 39 grams (or 18,000 to 39,000 mg). Omalizumab, at the highest dose is 375 mg (or 0.375 grams) at any one time. So, as you can see the addition of omalizumab to the current amount of IgG is negligible. Furthermore, most of the omalizumab is bound to IgE, and thus is far less than the original 375 mg floating around freely in the blood. on top of all this, there is no reported literature that discusses the interference of omalizumab on IgG testing, nor anything with Lyme disease. So some reassurance there. Lyme disease is a very tricky disease. there is no one test that will conclusively give you an indication one way or the other. Glenn - Pharm.D. --- In , McBride <mike.dmcbride@ ...> wrote: > > I wonder if this might not be a good question to ask the folks at Genetech, the manufacturers. Maybe you could wtie to them at http://www.xolair. com/index. html to get some information. Best wishes on this. Please let us know what you hear. > Mike McBride > > > > > > > ____________ _________ _________ __ > From: meagainbenny <meagainbenny@ ...> > > Sent: Monday, July 13, 2009 6:44:53 AM > Subject: [ ] Xolair and Lyme test > > > > > > Hi All, > > I'm a bit confused here and was hoping maybe someone knew something that could help me out. Back in early May, I was bitten by a tick, my MD did a 'Lyme test' 4 weeks out and 6 weeks out and they both came back negative. Each of the blood tests have been done at my PCP's office right after my bi-weekly Xolair appointments. I have all or most of the symptoms of Lyme Disease (night sweats, joint pain/swelling, etc...) so it has been perplexing as to why the tests are negative. I made an appointment with an Infectious Disease doctor who specializes in Lyme cases, so today when I got my Xolair, I got copies of the blood work to give to this new doctor. The blood work says that the Lyme tests are based on levels of IgG antibodies. So my question is, would Xolair block those antibodies and thus the test would be negative? I did some research online, but this is such an obscure thing, the answer doesn't seem to be readily available. > > Thank you for any help you can give me, > Meagan > > > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 14, 2009 Report Share Posted July 14, 2009 Leigh, Xolair does not create IgG, it *is* an IgG antibody. But it is a very specific IgG antibody. It is made to bind mostly IgE antibodies, and little else. It does hang around, you are correct. Both Xolair and natural IgG antibodies have long lives in the body, where after production/injection, half of it will will still be there 26 days later. Regardless, because the amount of Xolair being injected into an adult at even it's highest dose, still is quite negligible. Because of the way IgG and Xolair both act time wise in the body, with each injection , based on my previous message about total amount in the body, and considering Xolair has an absolute bioavailability of 62%, would look like this: range of total + Xolair = Total combined amount of IgG in highest average adult dose 375 mg x 62% 18,000-39,000 mg + 235 mg = 18,235 - 39,235 mg This is only adding 0.6% to 1.3% to the total amount of IgG in the body. *And* this is assuming that all of Xolair is acting like free IgG, which is not the case. Most of the drug will be bound up by IgE, neither of which (Xolair or IgE) will be available to the body. A very low fraction of 235 mg will thus be most appropriate for this calculation, maybe say 50 mg, to be generous, thus only 0.1% to 0.2% of an increase in total IgG in the body. I'm sorry for being so verbose here. I just am trying to make the point that the addition of Xolair to the total IgG count in the body will be negligible. Glenn Pharm.D. > > hmmm I would think the Igg which xolair creates hangs around for awhile just like the bound Ige does thus there could be a very cumulative elevation. > > > ________________________________ > From: fpa9 <fpa9@...> > > Sent: Monday, July 13, 2009 4:21:52 PM > Subject: [ ] Re: Xolair and Lyme test > > > > > > This is a good thought, but is overall not a concern. > > Xolair does not bind out IgG. Xolair is an IgG molecule, which binds IgE molecules only (on average a 2:1 ratio of omalizumab:IgE) . It is engineered to be that specific. So, to draw comparison, your IgG antibodies are not affected by omalizumab. > > Another question that will come up is " because omalizumab is an IgG antibody will it interfere with the results of an IgG test? " the answer is invariably, no. The reason for this is because IgG antibodies circulate in our blood at relatively high concentrations - the highest of all our antibodies. IgG exists as 660-1350 mg/dL as an average range. So, in an average adult's blood, the total IgG amount would probably range from 18 to 39 grams (or 18,000 to 39,000 mg). Omalizumab, at the highest dose is 375 mg (or 0.375 grams) at any one time. So, as you can see the addition of omalizumab to the current amount of IgG is negligible. Furthermore, most of the omalizumab is bound to IgE, and thus is far less than the original 375 mg floating around freely in the blood. > > on top of all this, there is no reported literature that discusses the interference of omalizumab on IgG testing, nor anything with Lyme disease. So some reassurance there. > > Lyme disease is a very tricky disease. there is no one test that will conclusively give you an indication one way or the other. > > Glenn - Pharm.D. > > --- In , McBride <mike.dmcbride@ ...> wrote: > > > > I wonder if this might not be a good question to ask the folks at Genetech, the manufacturers. Maybe you could wtie to them at http://www.xolair. com/index. html to get some information. Best wishes on this. Please let us know what you hear. > > Mike McBride > > > > > > > > > > > > > > ____________ _________ _________ __ > > From: meagainbenny <meagainbenny@ ...> > > > > Sent: Monday, July 13, 2009 6:44:53 AM > > Subject: [ ] Xolair and Lyme test > > > > > > > > > > > > Hi All, > > > > I'm a bit confused here and was hoping maybe someone knew something that could help me out. Back in early May, I was bitten by a tick, my MD did a 'Lyme test' 4 weeks out and 6 weeks out and they both came back negative. Each of the blood tests have been done at my PCP's office right after my bi-weekly Xolair appointments. I have all or most of the symptoms of Lyme Disease (night sweats, joint pain/swelling, etc...) so it has been perplexing as to why the tests are negative. I made an appointment with an Infectious Disease doctor who specializes in Lyme cases, so today when I got my Xolair, I got copies of the blood work to give to this new doctor. The blood work says that the Lyme tests are based on levels of IgG antibodies. So my question is, would Xolair block those antibodies and thus the test would be negative? I did some research online, but this is such an obscure thing, the answer doesn't seem to be readily available. > > > > Thank you for any help you can give me, > > Meagan > > > > > > > > > > > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 14, 2009 Report Share Posted July 14, 2009 Thank you so much for your help, I will let you know what the specialist says. Meagan > > > > hmmm I would think the Igg which xolair creates hangs around for awhile just like the bound Ige does thus there could be a very cumulative elevation. > > > > > > ________________________________ > > From: fpa9 <fpa9@> > > > > Sent: Monday, July 13, 2009 4:21:52 PM > > Subject: [ ] Re: Xolair and Lyme test > > > > > > > > > > > > This is a good thought, but is overall not a concern. > > > > Xolair does not bind out IgG. Xolair is an IgG molecule, which binds IgE molecules only (on average a 2:1 ratio of omalizumab:IgE) . It is engineered to be that specific. So, to draw comparison, your IgG antibodies are not affected by omalizumab. > > > > Another question that will come up is " because omalizumab is an IgG antibody will it interfere with the results of an IgG test? " the answer is invariably, no. The reason for this is because IgG antibodies circulate in our blood at relatively high concentrations - the highest of all our antibodies. IgG exists as 660-1350 mg/dL as an average range. So, in an average adult's blood, the total IgG amount would probably range from 18 to 39 grams (or 18,000 to 39,000 mg). Omalizumab, at the highest dose is 375 mg (or 0.375 grams) at any one time. So, as you can see the addition of omalizumab to the current amount of IgG is negligible. Furthermore, most of the omalizumab is bound to IgE, and thus is far less than the original 375 mg floating around freely in the blood. > > > > on top of all this, there is no reported literature that discusses the interference of omalizumab on IgG testing, nor anything with Lyme disease. So some reassurance there. > > > > Lyme disease is a very tricky disease. there is no one test that will conclusively give you an indication one way or the other. > > > > Glenn - Pharm.D. > > > > --- In , McBride <mike.dmcbride@ ...> wrote: > > > > > > I wonder if this might not be a good question to ask the folks at Genetech, the manufacturers. Maybe you could wtie to them at http://www.xolair. com/index. html to get some information. Best wishes on this. Please let us know what you hear. > > > Mike McBride > > > > > > > > > > > > > > > > > > > > > ____________ _________ _________ __ > > > From: meagainbenny <meagainbenny@ ...> > > > > > > Sent: Monday, July 13, 2009 6:44:53 AM > > > Subject: [ ] Xolair and Lyme test > > > > > > > > > > > > > > > > > > Hi All, > > > > > > I'm a bit confused here and was hoping maybe someone knew something that could help me out. Back in early May, I was bitten by a tick, my MD did a 'Lyme test' 4 weeks out and 6 weeks out and they both came back negative. Each of the blood tests have been done at my PCP's office right after my bi-weekly Xolair appointments. I have all or most of the symptoms of Lyme Disease (night sweats, joint pain/swelling, etc...) so it has been perplexing as to why the tests are negative. I made an appointment with an Infectious Disease doctor who specializes in Lyme cases, so today when I got my Xolair, I got copies of the blood work to give to this new doctor. The blood work says that the Lyme tests are based on levels of IgG antibodies. So my question is, would Xolair block those antibodies and thus the test would be negative? I did some research online, but this is such an obscure thing, the answer doesn't seem to be readily available. > > > > > > Thank you for any help you can give me, > > > Meagan > > > > > > > > > > > > > > > > > > > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 14, 2009 Report Share Posted July 14, 2009 When you are on the borderline for obtaining IVIG, any extra IGG can mess up your chances for obtaining the product. Leigh ________________________________ From: fpa9 <fpa9@...> Sent: Tuesday, July 14, 2009 7:04:47 AM Subject: [ ] Re: Xolair and Lyme test Leigh, Xolair does not create IgG, it *is* an IgG antibody. But it is a very specific IgG antibody. It is made to bind mostly IgE antibodies, and little else. It does hang around, you are correct. Both Xolair and natural IgG antibodies have long lives in the body, where after production/injectio n, half of it will will still be there 26 days later. Regardless, because the amount of Xolair being injected into an adult at even it's highest dose, still is quite negligible. Because of the way IgG and Xolair both act time wise in the body, with each injection , based on my previous message about total amount in the body, and considering Xolair has an absolute bioavailability of 62%, would look like this: range of total + Xolair = Total combined amount of IgG in highest average adult dose 375 mg x 62% 18,000-39,000 mg + 235 mg = 18,235 - 39,235 mg This is only adding 0.6% to 1.3% to the total amount of IgG in the body. *And* this is assuming that all of Xolair is acting like free IgG, which is not the case. Most of the drug will be bound up by IgE, neither of which (Xolair or IgE) will be available to the body. A very low fraction of 235 mg will thus be most appropriate for this calculation, maybe say 50 mg, to be generous, thus only 0.1% to 0.2% of an increase in total IgG in the body. I'm sorry for being so verbose here. I just am trying to make the point that the addition of Xolair to the total IgG count in the body will be negligible. Glenn Pharm.D. --- In , Leigh McCall-Alton <mccallalton@ ...> wrote: > > hmmm I would think the Igg which xolair creates hangs around for awhile just like the bound Ige does thus there could be a very cumulative elevation. > > > ____________ _________ _________ __ > From: fpa9 <fpa9@...> > > Sent: Monday, July 13, 2009 4:21:52 PM > Subject: [ ] Re: Xolair and Lyme test > > > > > > This is a good thought, but is overall not a concern. > > Xolair does not bind out IgG. Xolair is an IgG molecule, which binds IgE molecules only (on average a 2:1 ratio of omalizumab:IgE) . It is engineered to be that specific. So, to draw comparison, your IgG antibodies are not affected by omalizumab. > > Another question that will come up is " because omalizumab is an IgG antibody will it interfere with the results of an IgG test? " the answer is invariably, no. The reason for this is because IgG antibodies circulate in our blood at relatively high concentrations - the highest of all our antibodies. IgG exists as 660-1350 mg/dL as an average range. So, in an average adult's blood, the total IgG amount would probably range from 18 to 39 grams (or 18,000 to 39,000 mg). Omalizumab, at the highest dose is 375 mg (or 0.375 grams) at any one time. So, as you can see the addition of omalizumab to the current amount of IgG is negligible. Furthermore, most of the omalizumab is bound to IgE, and thus is far less than the original 375 mg floating around freely in the blood. > > on top of all this, there is no reported literature that discusses the interference of omalizumab on IgG testing, nor anything with Lyme disease. So some reassurance there. > > Lyme disease is a very tricky disease. there is no one test that will conclusively give you an indication one way or the other. > > Glenn - Pharm.D. > > --- In , McBride <mike.dmcbride@ ...> wrote: > > > > I wonder if this might not be a good question to ask the folks at Genetech, the manufacturers. Maybe you could wtie to them at http://www.xolair. com/index. html to get some information. Best wishes on this. Please let us know what you hear. > > Mike McBride > > > > > > > > > > > > > > ____________ _________ _________ __ > > From: meagainbenny <meagainbenny@ ...> > > > > Sent: Monday, July 13, 2009 6:44:53 AM > > Subject: [ ] Xolair and Lyme test > > > > > > > > > > > > Hi All, > > > > I'm a bit confused here and was hoping maybe someone knew something that could help me out. Back in early May, I was bitten by a tick, my MD did a 'Lyme test' 4 weeks out and 6 weeks out and they both came back negative. Each of the blood tests have been done at my PCP's office right after my bi-weekly Xolair appointments. I have all or most of the symptoms of Lyme Disease (night sweats, joint pain/swelling, etc...) so it has been perplexing as to why the tests are negative. I made an appointment with an Infectious Disease doctor who specializes in Lyme cases, so today when I got my Xolair, I got copies of the blood work to give to this new doctor. The blood work says that the Lyme tests are based on levels of IgG antibodies. So my question is, would Xolair block those antibodies and thus the test would be negative? I did some research online, but this is such an obscure thing, the answer doesn't seem to be readily available. > > > > Thank you for any help you can give me, > > Meagan > > > > > > > > > > > > > > > > Quote Link to comment Share on other sites More sharing options...
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