Sjogren’s syndrome

Within the defense mechanisms of the immune system we have some types of lymphocytes, B lymphocytes, which are transformed into plasma cells, the cells responsible for generating antibodies, compounds that detect parts of agents external to the body - antigens -, in order to be able to do so. identify potential threats and attack them, as they do with bacteria and viruses.

Under normal conditions, plasma cells only recognize foreign elements as foreign to the body and have mechanisms to also recognize cells and proteins of the body. Now, when for various reasons there is an alteration in this ability to recognize organic components as their own, plasma cells can generate antibodies against the body itself and cause various alterations depending on the type of tissue, cell or protein that they attack. When this happens, it is called an autoimmune disease.

The exocrine glands are not immune to these possible alterations and when the body creates antibodies that attack these structures, the glands atrophy and cannot produce their normal secretions. When this occurs in several glands and other structures of the body are affected, it is said that the patient suffers from Sjögren's syndrome, named after the Swedish ophthalmologist who first described it.

How is it produced?

In the appearance of Sjögren's syndrome, it is believed that there are several factors that may be involved, both genetic and hormonal or due to previous infection with some type of virus.

It mainly affects women (9 women for every man), the majority aged between 40 and 60 years. A distinction is made between primary Sjögren's syndrome, which is the one that appears isolated, and secondary, which occurs associated with other diseases, such as rheumatoid arthritis (30%), systemic lupus erythematosus (20%), systemic sclerosis ( 30%) or other diseases to a lesser degree, such as primary biliary cirrhosis or hepatitis C.

Plasma cells invade the exocrine glands and create inflammation that in the long term causes these glands to atrophy and therefore unable to carry out their exocrine secretion function. The main autoantibodies involved in the appearance of this syndrome are called Ro or SS-A and La or SS-B.

Symptoms

The main manifestations of Sjögren's syndrome occur at the glandular level, but it is a systemic disease, with which several organs and systems can be affected.

The lacrimal glands are affected, with which there is a decrease or suppression of tear production, which produces xerophthalmia, dryness at the corneoconjunctival level, which causes constant irritation and an increased risk of suffering from keratoconjunctivitis and lesions of the cornea.

At the level of the oral mucosa, there is a decrease in salivation, which gives rise to xerostomia and the constant sensation of thirst, which leads to polydipsia. Lack of salivation alters the perception of taste and smell, makes speech and swallowing difficult, and leads to oral infections and cavities. Infiltration of plasma cells can produce a unilateral growth of one of the parotid glands.

The excretory glands of the skin and vaginal mucosa are also affected, causing significant xeroderma and vaginal dryness, which makes sexual intercourse difficult. With regard to systemic involvement, which is more common in young patients, it should be said that the main manifestations are:

• pulmonary, with decreased mucus secretion, which favors bronchial infections and atelectasis, lymphocytic alveolitis that in the long run can lead to fibrosis, amyloidosis or pulmonary hypertension.
• less frequent cardiovascular diseases, with the appearance of pericarditis, Raynaud's phenomenon or vasculitis.
• digestive systems, with dysphagia, chronic gastritis, intestinal malabsorption, pancreatitis or liver involvement.
• renal, with tubular acidosis or nephritis due to lymphocyte infiltrates.
• nervous, with vasculitis that can cause cerebral microinfarctions, peripheral nerve involvement or psychiatric disorders; they are more frequent in Sjögren's syndrome associated with systemic lupus erythematosus.
• thyroid involvement due to Hashimoto's thyroiditis.
• musculoskeletal, with arthritis of various joints, arthralgia or myositis less frequently.
• cutaneous, with erythema nodosum or vasculitis added to xeroderma.
• hematological, with chronic anemia, decreased leukocytes and increased eosinophils; lymphadenopathy and splenomegaly may be present.

Most of the patients remain stable, but in some cases the lesions can evolve into lymphoma, mainly non-Hodgkin type and which occurs at the renal, lymph node, lung or gastrointestinal level.

Diagnosis

The diagnosis will be suspected in patients who present symptoms of dryness, especially at the ocular or oral level. A correct physical examination and various tests should be carried out to assess the degree of dryness.

Salivary gland dysfunction will be studied mainly by assessing the volume of saliva produced in a given period of time. A gammagraphy that studies the salivary glands or an ultrasound may also be done. A minor salivary gland biopsy can be performed, but is not usually done because it is a painful technique.

The decrease in tear production will be quantified using the Schirmer test, which allows to assess tear production at a specific time. Observation of the eye with the slit lamp after using a specific stain will reveal keratoconjunctivitis sicca lesions suggestive of this syndrome.

At the level of the blood test, the existence of anemia and involvement of the number and proportion of leukocytes will be assessed. Look for the presence of Sjögren syndrome specific antibodies, Ro and La antibodies. Likewise, the presence of other antibodies involved in other pathologies associated with this disease, such as rheumatoid factor (RF), ANA or cryoglobulins, will also be determined. Serology will also be performed to determine the existence of hepatitis C virus infection.

There are 6 diagnostic criteria for Sjögren's syndrome and the presence of 4 of them is required to establish the diagnosis. These criteria are:

• eye symptoms
• eye signs
• oral symptoms
• oral signs
• minor salivary gland biopsy consistent with Sjögren's syndrome
• presence of Ro, La, ANA or FR antibodies

The appearance of lymphoma in these patients should be suspected if there are adenopathies, splenomegaly or the antibodies disappear when performing blood tests.

Treatment

Treatment is symptomatic, using artificial tears, moisturizers, vaginal ovules and proper hydration. In case of severe extraglandular manifestations, corticosteroids can be used and if these do not work, immunosuppressants.

Precautionary measures

Sjögren's syndrome is an autoimmune disease, so there are no preventive measures to avoid it.