Indices of inflammatory cell activity and pulmonary function in different stages of sarcoidosis

Biochemical changes in sarcoidosis

Biochemical markers in sarcoidosis are closely related to the immunological events and the activity of inflammatory effector cells at sites of granuloma formation. The markers can be measured in serum, then reflecting whole body concentration, or in BAL fluid, then indicating activity in the lung. Only calcium and ACE serum levels have gained a proven value in the clinical field.

Biochemical markers in sarcoidosis

The clinical course of sarcoidosis is varying and unpredictable. Once the diagnosis has been made, the clinician needs simple tests to detect and predict remission or progression, to determine whether treatment is effective or not, and to assess the clinical activity of the disease. Sarcoidosis is a multisystem disease, but the lungs are almost always involved. Traditionally, the clinical management has therefore included chest X-rays and lung function studies. Extrapulmonary lesions have been followed in different ways. Sensitive and reproducible biochemical tests would be helpful in evaluating the clinical course of patients with sarcoidosis, if they measure functions related to the granulomatous inflammation. This review will deal with measurements of serum and urinary calcium, and 1,25-dihydroxyvitamin D. The usefulness of single and serial determinations of lysozyme, angiotensin converting enzyme, beta 2-microglobulin, collagenase, carboxypeptidase and glucuronidase in serum, bronchoalveolar lavage fluid, and other biological fluids will be discussed.

Lactoferrin, lysozyme, and beta 2-microglobulin levels in cerebrospinal fluid: differential indices of CNS inflammation

The CSF levels of lactoferrin, lysozyme, and beta 2-microglobulin (beta 2 mu) were measured in patients with evident, probable, or possible inflammatory CNS reactions and compared to those found in neurologically apparently healthy patients. Patients with viral CNS infections had significantly raised beta 2 mu and lysozyme levels but normal lactoferrin levels, indicating a local activation of lymphocytes and monocytes but not of granulocytes. Patients with bacterial CNS infections had significantly raised levels of all three cell markers, but the increase of lysozyme and lactoferrin was relatively more pronounced than that of beta 2 mu, indicating that the inflammatory response to bacterial agents is dominated by monocytes and granulocytes. Patients with primary or secondary malignant brain tumors were characterized by a moderate increase of beta 2 mu and a considerable increase in both lysozyme and lactoferrin, i.e., the same protein pattern as observed in bacterial CNS infection. The lysozyme levels were moderately increased in half the patients with benign cerebral tumors while the levels of beta 2 mu and lactoferrin were normal, indicating that benign and malignant brain tumors induce different local inflammatory CNS reactions. Half the patients with pituitary gland adenoma had elevated beta 2 mu and lysozyme levels but normal lactoferrin levels, suggesting that immunological mechanisms are associated with the adenoma development. Patients with MS had moderately but significantly raised CSF levels of beta 2 mu and lysozyme and a third of them also had raised levels of lactoferrin, a protein pattern suggesting a low-active inflammatory process in CNS involving mononuclears and granulocytes. A similar protein pattern was found in Guillain-Barré syndrome. In cerebrosarcoidosis we noted considerably increased lysozyme and beta 2 mu but normal lactoferrin levels, consistent with the idea that the sarcoid granuloma mass is dominated by monocytic inflammatory cells. The data obtained indicate a clinical value of lactoferrin, lysozyme, and beta 2 mu as differential indices of inflammatory cell reactions taking place in various CNS processes.