Sarcoidosis Pathophysiology شرح بالعربي : الباثوفسيولوجى لمرض الساركويد
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Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology that is characterised by the presence of
non-caseating granulomas.
Broncho alveolar lavage shows a great increase in the overall number of cells;
a lymphocytosis (particularly CD4+
T-helper cells) is common.
Transbronchial biopsies show infiltration of the alveolar walls and interstitial spaces with leucocytes, mainly T lymphocytes, (that is why it is low in blood) prior to granuloma formation.
Sarcoidosis can affect any organ but has a predilection for the lungs (involvement in up to 90%).
Common extrathoracic manifestations include eye, skin or lymph nodes involvement, and constitu-tional upset with fatigue is a frequent and often refractory symptom.
Löfgren’s syndrome a combination of bilateral hilar lymphadenopathy, erythema nodosum, arthralgia and fever which usually resolves spontaneously without the need for treatment.
pulmonary symptoms
Although pulmonary involvement may be an incidental finding, cough, exertional breathlessness and vague chest discomfort are common presentations.
Even in symptomatic individuals the chest is often clear to auscultation, although wheeze may be evident if there is significant involvement of the airways with endobronchial disease.
Radiological stages of lung involvement:
Stage 1:bilateral hilar lymphadenopathy alone (BHL) - 55-90% spontaneous remission.
Stage 2:pulmonary infiltrates with BHL - 40-70% spontaneous remission.
Stage 3:pulmonary infiltrates without BHL- 10-20% spontaneous remission.
Stage 4: Lung fibrosis.