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Recent Research in Chronic Beryllium Disease
July 27‚ 2001 — Recent beryllium research topics include medical techniques for evaluating health problems in beryllium workers and the role of genetic susceptibility in chronic beryllium disease
Factors in Chronic Beryllium DiseaseBeryllium research at the University of Colorado Health Sciences Center involves T-cells‚ antigens‚ and alleles (Chest 2001; 120:S58; July 2001). T-cells are a class of white blood cells that fight infection and coordinate the immune system; antigens are substances that cause the production of antibodies. Alleles are different forms of the same gene. Caused by exposure to beryllium‚ chronic beryllium disease has sometimes been associated with particular human leukocyte antigen (HLA) alleles‚ especially certain “DP” alleles. These alleles may increase susceptibility to the disease.
The Colorado researchers developed T-cell lines from the lungs of four patients with chronic beryllium disease. These lines generally responded vigorously to the beryllium compound‚ beryllium sulfate‚ but not to other metallic compounds. The reactions of various antigen-presenting cells that had different HLA DP alleles were tested. The results indicated that only cells with certain types of HLA DP alleles reacted to beryllium compounds‚ thus providing more information about heightened predisposition to chronic beryllium disease.
A group at the Imperial College of Medicine in the United Kingdom also worked with T-cell lines derived from patients with chronic beryllium disease (J Immunol 2001 Mar 1;166(5):3549-55). They found a strong correlation between chronic beryllium disease and HLA DP alleles that contained glutamic acid positioned in a certain way. Glutamic acid is one of 20 amino acids‚ the building blocks that make up protein in the body. The sequence of amino acids in a protein is determined by genetics.
Medical Surveillance for Chronic Beryllium DiseaseIn another beryllium study‚ investigators looked at using the blood beryllium lymphocyte proliferation test (BeLPT) at regular intervals for purposes of medical surveillance (J Occup Environ Med 2001 Mar;43(3):231-7). Employees of a beryllium machining plant were screened with the BeLPT biennially. New employees were screened within three months of hire.
Of the 235 employees screened from 1994 to 1997‚ 15 had abnormal BeLPT results that indicated beryllium sensitization. Nine of these employees developed chronic beryllium disease. Four of the 15 cases were diagnosed within three months of their first beryllium exposure. From 1997 to 1999‚ 187 of the 235 employees participated in biennial screening; seven more had developed beryllium sensitization and chronic beryllium disease.
The results showed that beryllium sensitization can occur as early as within 50 days of first exposure. The researchers concluded the blood BeLPT should be used repeatedly and serially in beryllium disease surveillance to capture new or missed cases of sensitization and disease.