One of the most important cells in the body is the mast cell. These cells are found in the lymph nodes, skin, stomach, liver, lining of the lungs, spleen and intestine etc. internal organs. These mast cells –
- Play a main role to defend the immune system and protect these organs from potential diseases.
- They also release cytokines and histamines, which are "chemical alarms" and other immune system defenders to an area that is under attack and needs help.
- Mast cells are also believed to help in the growth of blood vessels.
- They help in healing a wound, by gathering together.
Researchers have found that there is no instance of human beings, with too few or no mast cells at all. Hence, it can be concluded or inferred that having no or very few mast cells, is not compatible with life. However, increased mast cells can happen which is known as mastocytosis. Let us see the symptoms, causes, diagnosis and treatment of mastocytosis.
What is Mastocytosis?
Produced in the bone marrow, the mast cells are very important in having good immunity. Though too few and no mast cells haven't been reported ever, there is a condition in which the presence of mast cells significantly increases in the body. This is called Mastocytosis.
Mastocytosis is a rare condition or disorder in which the bone marrow, skin, spleen, liver etc. organs experience an abnormal accumulation of the mast cells.
Types of Mastocytosis
Mastocytosis can occur in two forms. These are –
- Cutaneous Mastocytosis: As the name suggests, this is a type of mastocytosis that is associated with the abnormal growth of mast cells in the skin. The growths or lesions are spots and bumps on the skin. These can sometimes occur even as blisters. The mast cells infiltrate the skin in this condition. Cutaneous Mastocytosis is also known as urticaria pigmentosa. Children are found to be usually suffering from this type of Mastocytosis, though the adults too can be affected. It is on rare occasions that the cutaneous mastocytosis progresses into systemic mastocytosis for children. However, with adults, this can also certainly occur. Cutaneous Mastocytosis can be of different types. These are –
- Maculopapular Cutaneous Mastocytosis: This is the most common type of cutaneous mastocytosis. It can occur both in infants as well as adults. Though it rarely spreads from one tissue to the other, it also doesn't subside with time.
- Solitary Mastocytoma: This type of mastocytosis occurs in infants, who get thick yellowish brown or reddish brown patch of skin. This gradually and largely subsides with time.
- Telangiectatic Cutaneous Mastocytosis: This type of mastocytosis can be very persistent and lead to systemic mastocytosis.
- Diffuse Cutaneous Mastocytosis: In this type, there is a widespread blistering of the skin on the infants. In case of adults, the skin gets a leathery thickened appearance.
- Plaque-type Mastocytoma
- Solitary and Multiple Nodular Mastocytoma
A person can acquire any of these types of Cutaneous Mastocytosis.
- Systemic Mastocytosis: When mastocytosis or accumulation of the mast cells occurs in the internal organs and tissues such as spleen, liver, small intestine and bone marrow, along with the skin, it is known as systemic mastocytosis. When the mast cells accumulate in these organs, the organs continue to perform and function normally. However, few disruptions can be found. When too many mast cells are accumulated in the organs, the organs may stop functioning normally. In fact, the excessive number of mast cell accumulation in the bone marrow may disrupt the production of blood cells. This can cause serious blood disorders like leukaemia. These conditions can be life threatening.
The different types of Systemic Mastocytosis are –
- Systemic Mastocytosis with Associated Clonal Haematological Non-mast Cell Lineage Disease: In this condition, there is an increased production of blood cells and this is associated with concurrent myeloproliferative neoplasms. Even myelodysplasia or very little production of blood cells can also be associated with this condition. About 1/3rd of all systemic Mastocytosis is of this type.
- Indolent Systemic Mastocytosis: This is the most common type of systemic mastocytosis.
- Aggressive Systemic Mastocytosis: Organ failure due to uncontrolled proliferation of neoplastic cells is associated with this type.
These different kinds of systemic mastocytosis mostly occur in adults. They are very rare in infants or children.
Symptoms of Mastocytosis:
The symptoms of Mastocytosis largely depend on the type of Mastocytosis that a person is suffering from. However, the common and usual signs and symptoms of this condition include –
- Skin lesions, skin reactions, flushing and itching
- Abdominal discomfort and cramping
- Vomiting and nausea
- Rhinitis, bronchitis and conjunctivitis and similar infections
- Pain in bones and muscles
- Inflammation of throat, nose and ears
- Peptic ulcer caused by increased production of stomach acids.
Causes of Mastocytosis
Though the exact causes of Mastocytosis are not clearly known; scientists and researchers still associate this condition with genetic mutations or changes in genes. This gene mutation is known as the KIT mutation. When the KIT gene mutates on the 4q12 chromosome, cellular reproduction is increased. As a result of the mutation, the mast cells become more sensitive to SCF or Stem Cell Factor signalling protein. Since SCF is responsible in stimulating the production of mast cells, an overgrowth of the mast cells takes place.
In most cases, the excessive production of mast cells or Mastocytosis is a spontaneous event. In some cases, there is a family history associated with this condition.
Pathophysiology of Mastocytosis
The increased growth of mast cell through lesions, in case of the cutaneous mastocytosis, is associated with –
- Melanin pigment production
- Melanocyte proliferation
- Mast cell proliferation.
It is because of the induction of the melanocytes that the hyperpigmentation occurs. The other factors that are associated with this condition include the apoptosis-preventing protein BCL-2 and the D816V that activates the mutation of c-kit.
Epidemiology of Mastocytosis
Mastocytosis is mostly reported to have occurred in whites. It might be because the skin lesions are less prominently visible in highly pigmented skin. It occurs more in children, especially during their infancy. As they reach their puberty, the condition gradually subsides. However, it can also occur in patients in their 30 to 49 years of age. However, no evidence has been found that can prove a sex predilection. It occurs equally in males and females.
Diagnosis of Mastocytosis
As you visit a doctor with visible skin lesions, patchy and red skin with itchiness and inflammation, the dermatologist will recognise this sign and even a physical examination can diagnose the occurrence of cutaneous mastocytosis. The doctor will also run a biopsy test that will check the amount of mast cells present in the body.
In case of systemic mastocytosis, the tests that are performed are –
- Blood Test for Mastocytosis: Measuring of tryptase level in the blood and full blood count
- DEXA Scan to Detect Mastocytosis: Measuring of bone density
- Ultrasound: Checking for spleen and liver enlargement.
- Biopsy of Bone marrow.
Treatment of Mastocytosis
Mastocytosis doesn't have any cure or treatment as such. Only the symptoms are reduced. To reduce the symptoms of cutaneous mastocytosis, corticosteroid medicines are given. Steroid creams can reduce the mast cells and thus, can reduce the release of histamines that actually causes the inflammation and patchiness of the skin.
Antihistamines are given to reduce this redness and itchiness from the skin. The other treatments include –
- Cromolyn sodium to reduce abdomen cramping
- Steroid to treat mal-absorption and malnutrition
- Aspirin to relieve flushing
- Chemotherapy for mast cell leukaemia is a must. The common drugs that are given in this condition are Fludarabine, Etoposide, Daunomycin, Hydroxyurea, Mercaptopurine, Cladribine, and Cytarabine.
- Sometimes, bone marrow stem cell transplant may also be required.
Systemic mastocytosis has no cure. In order to keep the symptoms under control, antihistamines such as H1 and H2 blockers are given. The H2 blockers also help is reducing peptic ulcer. To reduce the effect of systemic mastocytosis on bone marrow, interferon-alpha is given.
Prognosis of Mastocytosis
Usually, most patients of Mastocytosis get to resolve the condition by their puberty and in that respect, mastocytosis has a great prognosis level. The number of lesions also decreases by 10% in every year. In case of tryptase level increase, hospitalization may be needed for daily monitoring. It is only in rare cases that the condition leads to leukaemia.
Complications Associated with Mastocytosis
Usually, mastocytosis has a good prognosis and by the time the patient reaches puberty, the condition subsides. However, in some cases, where the patient suffers from systemic mastocytosis, there are chances of developing a lifelong blood disorder, even leukaemia.
Since Mastocytosis doesn't have a proper treatment and some of its types can be difficult to cope with or manage, it is a must that medical attention is sought after.