Is there a cure for MCAS?

There is currently no cure for MCAS and experts in the field are of the widespread belief that there will no cure for MCAS for the foreseeable future.

MCAS is driven by somatic genetic mutations within the hematopoietic stem cells in bone marrow that give birth to mast cells. The mutations found thus far are known to involve defects in mast cell regulatory genes such as KIT. The KIT gene provides instructions for making a member of a protein family called receptor tyrosine kinases.

These somatic (not inherited) mutations are a one way ticket. Whether these mutations occur due to chemical exposure from substances like benzene or whether they occur due to endogenous mast cell mediator overload (which can occur during trauma), they CANNOT be undone.

Can antihistamines cure MCAS?

No antihistamines do not cure MCAS, there is no cure for MCAS.

When mast cells degranulate they release chemical mediators in a controlled manner to drive other actions within the body. In fact even without degranulation, mast cells “leak” potent chemical mediators constantly as part of their normal function of guiding growth & development throughout the body.

When mast cells are behaving normally they output the correct mediator, for the correct reasons and for the correct duration. When a patient suffers Mast Cell Activation Syndrome their mast cells output incorrect mediators for incorrect reasons and for incorrect durations.

Aberrant mast cell behaviour as described above can cause utter havoc in every system within the body. Cardiovascular system, gastrointestinal tract, genitourinary tract, lymph system, the integumentary system, the central nervous system and so on.

One of the mast cell mediators that appears to be consistently over produced in approximately a quarter of MCAS patients is histamine. Most people will know that histamine is involved in inflammatory response and with allergies & anaphylaxis.

However, people may not be aware that histamine has a wide array of effects and is known to be involved in erections, emotions, cervix to brain communication, water retention, temperature regulation and the sleep wake cycle. So if histamine is being produced for the wrong reason and for the wrong duration this one single chemicals mediator can cause problems in all bodily systems.

If we know that histamine is a mast cell mediator that is overproduced in some MCAS patients then it makes sense to try to control what happens when it is overproduced. For example histamine landing on a H1 or H2 receptor of another mast cell can trigger that mast cell to itself produce histamine leading to a cascade effect.

As well as mast cells, other cells in the body can produce & respond to histamine and as a result a problem with histamine overproduction can lead to such varied symptoms as anxiety, flushing, itching, diarrhea & hypotension.

Antihistamines do not directly block the production of histamine but if histamine is produced, antihistamines lessens the body’s response to it.

At the time of writing (June 2020) there are no doctors in Ireland with MCAS expertise and so there are likely no doctors actively testing , diagnosing or treating MCAS.

For patients who suspect they may have MCAS, antihistamines are the first line of self help treatment along with a strategy to identify & avoid environmental triggers in what they eat, drink, breathe & wear. For many, self help is the only current hope they have for any MCAS treatment.

For the record mast cells can produce over 1,000 different potent mast cell mediators all with an array of effects. Histamine is just one of these.

Can a drug called Imatinib cure MCAS?

No Imatinib does not cure MCAS, there is no cure for MCAS.

Imatinib, sold under the brand name Gleevec in Ireland,is an oral medication” (of the tyrosine kinase inhibitor class) which has been shown useful for treating a variety of illnesses including both certain malignant conditions & certain non-malignant conditions.

Imatinib that was developed by a process called “rational drug design” and was designed to treat a particular philadelphia chromosome mutation that lead to a fatal cancer called chronic myeloid leukemia (CML). Imatinib was a game changer for CML and converted a fatal cancer into a manageable chronic condition.

It has been found that Imatinib can be very effective for “some” MCAS patients. For these MCAS patients who respond to Imatinib it has converted their MCAS into a manageable chronic condition.

The current cost of Gleevec in the USA is approximately $150,000 for a 1 year supply or $4111 per day.

In the USA, Imatinib is licenced to treat various cancers and also approved to treat some MCADs. In the EU, Imatinib is only licenced to treat cancer and is believed to be currently unavailable to MCAD patients in Ireland.

So if there is no cure for MCAS what is the point of a diagnosis?

While there is no cure, MCAS is a treatable illness and the aim of MCAS treatment is for patients to enjoy more good days than bad.

Correct diagnosis of any illness should lead to the most appropriate treatment.

For MCAS patients, suffering a variety of linked illnesses, an MCAS diagnosis offers the possibility of different treatments that may potentially offer a better outcome than their current treatment.

Initial simple steps that involve a strategy to identify & avoid triggers and trialling a H1 & H2 antihistamine regime may bring considerable relief to many patients but certainly not for all patients.

Further steps will require the involvement of a suitably qualified clinician or at least a doctor who is willing to work with the patient to learn how to get the illness under control. Further steps usually involve another class of drugs called mast cell stabilisers.

What are the consequences of not treating MCAS?

The consequences of not treating MCAS usually means not getting chronic inflammation under control and therefore allowing it to slowly escalate unhindered.

  • Chronic inflammation of the GI/GU tract may drive eventual malignancy
  • Chronic inflammation of the cardiovascular system is known to drive atherosclerosis and may lead to subsequent heart attacks.
  • Chronic inflammation of the central nervous system is known to drive anxiety & depression in some cases this can unfortunately lead to suicide.
  • There are many more symptoms that can escalate and lead to further harm.

How long before I feel better?

Some simple interventions as detailed above can sometimes make considerable improvements quickly.

Knowledge & research in mast cell biology & disease remains in its infancy and at present there is no way to reliably predict which treatments will best help which MCAS patients.

Trials of many medications often are needed by the individual patient to find the regimen which will best serve that patient.

Although a few MCAS patients are fortunate as to find very helpful medications within weeks to months of diagnosis, and quite inexpensively, it is common for MCAS patients to have to patiently, persistently & methodically try many medications over many months to years, eventually including quite expensive medications, before the available regimen which works best for the individual patient has been identified.

In time, advancing research likely will lead to better tests for identifying which particular MCAS patients are more likely to respond to any particular medication. This will hopefully shorten the time & lower the cost of getting an individual patient to the point of optimal management.