Přidat odpověď

A ještě si dovolím článeček k tématu, překládat nebudu, nemyslím, je to velmi easy English - na téma MMR vakcína a její schopnost indukovat přesmyk ve tvorbě imunoglobulinů, následkem zhoršení stavu z hlediska alergie (longterm).
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---------Infection of human B lymphocytes with MMR vaccine induces
IgE class switching.
Clin Immunol 2001 Sep;100(3):355-61
Farhad Imani and Kelly E Kehoe
Division of Clinical Immunology, Department of Medicine, The Johns Hopkins
University School of Medicine, Asthma and Allergy Center
FROM INCLUDED ABSTRACT:
Circulating immunoglobulin E (IgE) is one of the characteristics of human allergic
diseases including allergic asthma.
We recently showed that infection of human B cells with rhinovirus or measles
virus could lead to the initial steps of IgE class switching.
Since many viral vaccines are live viruses, we speculated that live virus vaccines
may also induce IgE class switching in human B cells.
To examine this possibility, we selected the commonly used live attenuated
measles mumps rubella (MMR) vaccine.
Here, we show that infection of a human IgM B cell line with MMR resulted in the
expression of germline epsilon transcript. In addition, infection of freshly prepared
human PBLs with this vaccine resulted in the expression of mature IgE mRNA
transcript.
Our data suggest that a potential side effect of vaccination with live attenuated
viruses may be an increase in the expression of IgE. [WOW!]
THESE AUTHORS ALSO NOTE:
“A key component in allergic reactions is increased levels of circulating
immunoglobulin E (IgE).”
Mature resting B lymphocytes express IgM.
However, these B lymphocytes can differentiate to “switch” from immunoglobulin
class IgM to secreting immunoglobulins IgG, IgA, or IgE.
If the switch is to IgE, IgE molecules will bind to surface receptors of mast cells
and basophils, causing the release of histamine and leukotrienes.
Histamine and leukotrienes are responsible for many of the clinical manifestations
of the allergic response.
2
“The incidence rate of allergic reactions such as asthma has increased in the past
20 years.” Proposed reasons for this increase include:
(1) Improvements in home construction leading to an increase in the indoor
humidity and temperature resulting in an increase in house dust mite and
cockroach allergens.
(2) Bacterial products [endotoxins] are thought to down-regulate allergic
differentiation. Therefore, “an increase in antibiotic usage and a subsequent
reduction in bacterial infections has created an environment that may favor
allergic conditions.”
(3) A decrease in childhood outdoor activities and an increase in sedentary life
styles may contribute to the increase in asthma.
(4) Viral infections can cause IgE class switching in human B cells.
Specifically, live attenuated viral vaccines such as polio, MMR (mumps,
measles, rubella), and varicella can induce IgE class switching.
In this article, the authors provide evidence that infection with MMR vaccine can
cause IgE class switching in human B cells.[WOW!]
Since MMR vaccine is commonly used during childhood immunization, the authors
selected MMR vaccine for their experiments.
The authors showed that MMR vaccine infection induces IgE class switching in
freshly prepared human peripheral blood lymphocytes.
DISCUSSION
“Epidemiological studies have shown that one of the key characteristics of allergic
diseases is an increase in circulating IgE levels.”
“It is well documented that viral infections lead to the induction of IgG
expression.”
However, viral infections with rubella virus have been associated with the
expression of IgE.
“Childhood vaccines such as MMR that are live attenuated viruses could also
induce IgE class switching.”
“The viral vaccine titer that was used in these experiments was 10 times less than
the amount used in childhood immunization.”
3
The “data suggest that attenuated virus vaccine strains can replicate in the
immunized host and thus may have the opportunity to interact with B
lymphocytes.”
“Infection with measles virus is known to induce a robust Th1 immune response,”
which down-regulate [reduce] IgE class switching.
Therefore, infection of B cells with measles virus alone did not induce
IgE class switching.
The rubella vaccine was consistently the most potent inducer of IgE class
switching.
“Our data showed that live virus MMR vaccine can induce IgE class switching in
human B cells.”
“This is particularly relevant because events during the first 3 years of life have
been shown to be important in the induction of lifelong allergic reactions.”
Also, “the genetic background of each individual is critical to the expression of
allergen-specific IgE protein and subsequently to the induction of allergic
reactions.”
“Even though contradictory data exist, there is increasing evidence for induction of
atopic reactions secondary to childhood viral immunizations.”
“It is possible that a side effect of viral vaccination constitutes an increase in the
incidence of IgE-mediated disorders.”
KEY POINTS FROM DAN MURPHY
(1) IgE is the primary cause of the clinical manifestations of the allergic
response, including asthsma.
(2) Bacterial infections and endotoxin bacterial byproducts reduce IgE, and
therefore antibiotics are part of the problem of increasing allergic response.
(3) Measles infections reduces IgE.
(4) Mumps and Rubella, especially rubella infection increase IgE. Vaccination
with live attenuated mumps and rubella virus also increase IgE, and the allergic
response.
(5) The causes of IgE “switching” in first 3 years of life are most important
because the propensity to then produce IgE and allergic reactions is lifelong.