Occupational lung diseases –general principles and approaches and beryllosis review

By
Mahmoud E. Abou El-Magd
Assistant lecturer of pulmonary and critical care medicine
OCCUPATIONAL LUNG
DISEASES –GENERAL
PRINCIPLES AND
APPROACHES

DEFINITIONS
OCCUPATIONAL LUNG DISEASES 2
• Damage to the lungs caused by dusts or fumes or
noxious substances inhaled by the workers in certain
specific occupations is known as “Occupational Lung
Diseases”.
• „Pneumoconiosis is the accumulation of the dust in the
lungs and the tissue reactions to its presence.
• „ Dust is an aerosol composed of solid inanimate
particles.

IMPORTANCE OF OCCUPATIONAL LUNG
DISEASES
• Knowledge of cause may affect patient management
and prognosis and may prevent further disease
progression in the affected person.
• „Establishment of cause may have significant legal,
financial and social implications for the patient.
• „The recognition of occupational and environmental risk
factors can also have important public health and
policy consequences

GLOBAL BURDEN
• Health burden: 2 million work related death per year.
„Fatalities Attributable to work:
• Circulatory diseases 23%
• Respiratory diseases 7%
• Cancer 32%
• Accidents and violence 19%
• Other causes 2%
• „Tip of the iceberg : 160 million nonfatal diseases.

Occupational lung diseases can be classified according to
several schemes.
• „Clinical presentation
• „Type of exposure to agent
Organic dusts
Inorganic dusts
Metals
Biological factors

• the etiology of many lung diseases may be multi-factorial and
occupational factors may interact with other factors.
• „The dose of exposure is an important determinant of the
proportion of people affected or the severity of disease.
• „Individual differences in susceptibility to exposures do exist.
• „ The effects of a given occupational or environmental lung
exposure occur after the exposure with a predictable latency
interval

The effects of an inhaled agent depend on
many factors:
• „its physical and chemical properties
• „the susceptibility of the exposed person
• „the site of deposition within the bronchial tree

PHYSICAL PROPERTIES
• physical state (solid particulates, mist, vapor and gases )
• solubility
• size, shape and density
• concentration
• penetrability
• radioactivity

CHEMICAL PROPERTIES
• alkalinity and acidity
• fibrogenicity
• antigenicity

• There are two important phases in the workup of any
patient with a potential occupational or environmental
lung disease.
• „1. General approach: To define and characterize the
nature and extent of the respiratory illness, regardless
of the suspected origin.
• A detailed history
• Physical examination
• Appropriate diagnostic tools

• 2. To determine the extent to which the disease or
symptom complex is caused or exacerbated by an
exposure at work or in the environment.
• Occupational and environmental history is ths single
most helpful tool in the diagnostic workup

OCCUPATIONAL AND
ENVIRONMENTAL HISTORY
• Employment details
• Job title
• Type of industry and specific work
• Years employed
• „Exposure information

• General description of job process and overall hygiene
• Materials wed by worker and others
• Specific workplace exposures
• Ventilation / exhaust system
• Use of respiratory protection
• Industrial hygiene informations provided by the
employer to Industrial hygiene informations provided by
the employer to the employee.

• environmental non-occupational factors
• Smoking
• Diet
• Hobbies
• „Details about past employments in chronological order

PHYSICAL EXAMINATION
• Generally unrevealing about specific cause.
• „It is most helpful in ruling out non-occupational causes
of respiratory symptoms or diseases (cardiac problems
or connective tissue disorders).

CHEST RADIOGRAPHY
• It is the most important diagnostic test for occupational
lung disease.
• „Under certain circumstances, the chest radiograph can
be unique or highly suggestive of an occupational
disorder and may be sufficient, along with an
appropriate exposure history, to establish a diagnosis.

ASBESTOSIS

LIMITATIONS
• The chest radiographic findings can be nonspecific.
• „Conventional chest radiography is insensitive, missing
as many as 10 to 15 percent of cases with
pathologically documented disease.
• „Interpersonal variations

COMPUTED TOMOGRAPHY
• Conventional and HRCT scanning are highly sensitive
for diagnosis of pleural diseases and useful for
improved visualization of parenchymal abnormalities.
• „HRCT findings are usually non specific, but
occasionally certain features and distribution pattern
may suggest a specific cause and may help narrow the
differential diagnosis.

PHYSIOLOGICAL METHODS
• the most important tool to assess functional respiratory
status in patients with occupational lung disease.
Generally not specific but useful in :
• Evaluating dyspnoea of various causes.
• Differentiating obstructive from restrictive defects.
• Assessing the degree of pulmonary impairment.

METHODS
• Spirometry
• „Lung volumes
• „Diffusing capacity
• „Methocholine challenge test
• „Preshift and postshift FEV1 measurements
• „Serial measurements of peak expiratory flow rates
• „Specific inhalation challenge tests

CARDIOPULMONARY
EXERCISE TESTING
• Used to assess functional impairment and disease progression.
• „Can help distinguish among cardiac, pulmonary causes of
dyspnoea .

PATHOLOGIC EXAMINATION
Methods used to obtain specimens for pathologic
examination :
• „Bronchoscopy
• „Thoracoscopy
• „Open lung biopsy

BRONCHOALVEOLAR LAVAGE
• A predominance of lymphocytes suggests certain diagnoses
such as sarcoidosis, hypersensitivity pneumonitis or beryllium
disease (but is not by itself diagnostic).
• „The diagnosis of beryllium disease can be established with the
finding of a positive lymphocyte transformation in the BAL cells
of exposed patients.
• „ Characteristic multinucleated giant cells may be seen in the
BAL fluid of patients with hard-metal lung disease.

TRANSBRONCHIAL LUNG
BIOPSIES
• TBLB yield only small tissue samples that may be adequate to
diagnose disorders such as interstitial fibrosis, but are often
unable to shed light on the reason for the pathology that is
noted.
• „They are most helpful in diagnosing granulomatous interstitial
diseases such as sarcoidosis, beryllium disease and
hypersensitivity pneumonitis and diffuse malignant processes.

METHODS USED TO ANALYZE
DUST CONTENT OF LUNG TISSUE
• „Light microscopic evaluation with polarization
• „Radiographic fluorescence scanning electron microscopy
• „Energy dispersion radiographic spectroscopy

ASBESTOS FIBRE SEEN UNDER
POLARIZED LIGHT MICROSCOPE

INTRODUCTION
• Chronic beryllium disease - Chronic beryllium lung disease –
Berylliosis – Beryllium granulomatosis - Beryllium pneumonosis .
• Chronic beryllium disease (CBD) is an occupational hypersensitivity
disorder caused by beryllium exposure at the workplace. It is
characterised by non-caseating, non-necrotising granulomata within
the affected organs,most frequently lung and skin.
• CBD shares many clinical and histopathological features with
sarcoidosis and was first described in 1946 when 17 fluorescent lamp
workers presented with a syndrome of advanced pulmonary
granulomatous disease

DEFINITIONS
A patient is considered to have chronic beryllium disease
(CBD) if all of the following are present:
• A history of any beryllium exposure
• A positive blood or bronchoalveolar lavage (BAL)
beryllium lymphocyte proliferation test (BeLPT)
• Non-caseating granulomas on lung biopsy

EXPOSURE
Exposure to beryllium may occur among workers in the following
industries :
• Heavy beryllium-using industries: metal and metal alloy
(beryllium-copper) machine shops, electronics, defense industry,
and beryllium extraction
• Other beryllium-using industries: automotive, ceramic, computer,
aerospace, metal reclamation, electronics and computer
recycling, jewelry making, and dental alloy/appliance

• The exact exposure-response relationship for CBD is unclear.
• Both the dose and duration of beryllium exposure appear to be
associated with an increased risk of sensitization and disease,
with rates as high as 20 percent in certain higher exposure work
tasks (eg, beryllium ceramics, machining, rod and wire
production) .
• The current US Occupational Safety and Health Administration
(OSHA) industrial exposure limit for airborne beryllium (2 mcg/m
3 , time weighted average exposure for an eight hour day) is not
completely protective against CBD .

• Some individuals develop clinically significant illness even at
extremely low levels of exposure or after an exposure as short
as three months .
• Community acquired chronic beryllium disease has also been
described in a small number of residents living within five miles
of beryllium manufacturing facilities .
• In a community survey of residents without occupational
exposure to beryllium, disease manifestations sometimes
developed 20 to 50 years after community-based exposure had
ceased and were associated with substantial morbidity.

PATHOGENESIS
• The pathogenesis of chronic beryllium disease appears to involve a
combination of an immunologic response to beryllium exposure and an
underlying genetic susceptibility
• In patients with CBD and in beryllium-sensitized patients, beryllium elicits an
immunologic reaction with characteristics of a cell-mediated or delayed
hypersensitivity reaction
• These characteristics include beryllium-specific sensitization of T cells,
proliferation of T cells upon re-exposure, production and release of
proinflammatory cytokines, and granulomatous inflammation.

ACUTE DISEASE
• Acute berylliosis is caused by high dose beryllium exposure and
shares clinical characteristics with acute sarcoidosis .
• Patients develop dose-dependent diffuse interstitial infiltrates,
dyspnea, fatigue, fever ,night sweats, and cough. The onset is
usually immediate but maybe delayed for up to 3days.
• Pulmonary function tests reveal obstructive and/or restrictive lung
disease with impaired gas exchange.

• Biopsy specimens of the lung show a lymphocytic
interstitial pneumonitis indistinguishable from chemical
pneumonitis due to other causes.
• Approximately one third of the acute cases progress to
chronic .
• Although the acute disease is mainly of historical
interest, sporadic cases are still reported

CHRONIC DISEASE
• The latency period between initial beryllium exposure and onset of symptoms
varies from three months to 30 years .
• The clinical manifestations of CBD are nonspecific .
• Common symptoms include dry cough, shortness of breath, fever, night
sweats, fatigue, and weight loss .
• Bronchial involvement can produce symptoms similar to those of asthma.
• Pulmonary examination typically reveals bibasilar crackles; more advanced
disease may be associated with signs of cor pulmonale and digital clubbing.

BERYLLIUM SKIN NODULES
Cutaneous nodules can
develop, especially if
beryllium has penetrated the
skin. These nodules tend to
be located on exposed areas
of skin, such as fingers and
forearms .

INVESTIGATIONS
• The results of routine laboratory tests are typically nonspecific.
• Measurement of the serum angiotensin converting enzyme
(ACE) level is not helpful, as it does not discriminate between
patients with CBD, beryllium sensitization, beryllium exposure,
or sarcoidosis .
• A tuberculin skin test may be performed in patients being
evaluated for CBD to exclude TB.

• A blood beryllium lymphocyte proliferation test (BeLPT)
is the most appropriate initial test for patients
suspected of having CBD.
• As in other granulomatous diseases of the lung,
increased production of calcitriol (the most active form
of vitamin D) by activated pulmonary macrophages can
lead to hypercalciuria and hypercalcemia

CHEST IMAGING STUDIES
• the chest radiograph may be normal or may show hilar
adenopathy or parenchymal abnormalities such as nodules,
ground glass, linear, or alveolar opacities.
• The parenchymal abnormalities may be diffuse or may be more
prominent in the upper lobes.
• High resolution computed tomography (HRCT) is more sensitive
than a plain chest radiograph in identifying the changes of CBD;
however, high resolution CT scanning is normal in up to 25
percent of patients with biopsy-proven CBD .

• The HRCT findings associated with CBD include
parenchymal nodules of varying size, thickened septal
lines, ground glass opacities, cystic cavitation,
bronchial wall thickening, and adenopathy involving the
hilum or mediastinum .
• Pleural thickening may be observed adjacent to areas
of dense subpleural parenchymal nodules, but pleural
effusions are uncommon. Pneumothorax has been
reported .

PULMONARY FUNCTION
TESTS
• Pulmonary function tests are obtained in virtually all patients suspected of
having CBD on the basis of dyspnea, an abnormal chest radiograph, or a
history of exposure to beryllium.
• Diffusing lung capacity for carbon monoxide (DLCO) is commonly
diminished, although this test is less sensitive than arterial blood gas
analysis at rest and exercise.
• As the disease becomes more clinically apparent, spirometry shows airflow
limitation, restriction, or a mixed pattern.
• Pure restriction is a relatively late finding

DIFFERENTIAL DIAGNOSIS
• The differential diagnosis OF CBD includes sarcoidosis, other
granulomatous lung diseases, idiopathic pulmonary fibrosis,
hypersensitivity pneumonitis, and asthma .
• Due to the strong clinical and histopathological resemblance of
sarcoidosis and CBD, patients are sometimes misdiagnosed
with sarcoidosis until the history of exposure to beryllium is
elicited and beryllium hypersensitivity demonstrated with
specific testing. As an example, it is estimated that up to 6
percent of all patients diagnosed with sarcoidosis may actually
have CBD

DIAGNOSIS
• The diagnosis of CBD requires that all three of the following findings be
present: a history of beryllium exposure, a positive beryllium lymphocyte
proliferation test (BeLPT), and the presence of noncaseating granulomas
and/or mononuclear cell interstitial cell infiltrates on lung biopsy.
• When histopathology is unavailable, the diagnosis can be made based on
the history of exposure, a positive BeLPT, and imaging that shows
abnormalities consistent with CBD.
• As a general approach to diagnosis, all patients with clinical or radiographic
evidence of lung disease or an occupational or environmental history of
beryllium exposure should be evaluated for CBD.

BERYLLIUM LYMPHOCYTE
PROLIFERATION TEST
• The blood beryllium lymphocyte proliferation test
(BeLPT) is the most appropriate initial test for patients
suspected of having CBD.
• the standard industry surveillance tool for identifying
beryllium-exposed workers who are beryllium-
sensitized or in the early stages of CBD .
•

• The BeLPT is also used to correct misdiagnoses of
sarcoidosis .
• In the BeLPT assay, mononuclear cells from peripheral
blood or bronchoalveolar lavage (BAL) are exposed in
vitro to three different concentrations of beryllium salts
(eg, beryllium sulfate) for two different time intervals .

BRONCHOALVEOLAR LAVAGE
• For patients who have a positive peripheral blood BeLPT or a clear history of
exposure to beryllium, we perform bronchoscopy with a bronchoalveolar
lavage (BAL) to obtain cell counts and a sample of BAL mononuclear cells
for BeLPT testing.
• Approximately 10 to 35 percent of patients with beryllium sensitivity have a
negative BeLPT test on peripheral blood, but a positive test on BAL
mononuclear cells .
• occasionally BAL proliferation assays give false negative results due to a
significant excess of alveolar macrophages in the lavage, which is a common
finding among cigarette smokers .

TISSUE BIOPSY
• 4 to 6 endobronchial biopsies are typically obtained from a site where the
mucosa appears erythematous.
• if the mucosa appears normal throughout, endobronchial biopsies are
obtained from the main carina and a secondary carina .
• Transbronchial biopsies are typically obtained from an area of involved lung
(identified by the HRCT scan appearance), but not the same site as a BAL
performed during the same procedure.
• We typically obtain 8 to 10 transbronchial biopsy pieces (as tolerated by the
patient) to maximize the yield

• The typical pathologic findings of CBD are noncaseating
granulomas and/or mononuclear cell infiltrates in the bronchial
wall or lung interstitium. In some patients, the same pathology
can be detected in the regional lymph nodes
• Biopsies of beryllium-induced skin nodules also typically
demonstrate noncaseating granulomas.

MANAGEMENT
Management of CBD includes :
• avoidance of further exposure.
• supportive care.
• therapy with glucocorticoids or other immunosuppressive
agents, depending on the severity of symptoms, physiologic
impairment, and radiographic involvement.

SUPPORTIVE THERAPY
• Although not specifically studied in patients with CBD,
supportive therapies, including influenza and pneumococcal
vaccination and smoking cessation counselling, are provided to
all patients.
• supplemental oxygen and pulmonary rehabilitation are
prescribed as indicated.

GLUCOCORTICOID THERAPY
Indications :
• When the patient reports dyspnea or cough.
• when there has been a greater than 10 percent decline in lung volumes or
gas exchange compared to baseline.
• when the patient has abnormal physiology at baseline (eg, lung volumes or
DLCO less than 70 percent of predicted).
• Patients with beryllium sensitization in the absence of CBD do not require
treatment, but should undergo annual or biennial evaluation for progression
into CBD .

• Patients who have documented CBD, but minimal or absent symptoms and
physiologic abnormalities, also do not require active treatment, but are
reassessed at 6 to 12 month intervals.
• the usual initial dose is 0.5 to 0.6 mg/kg (approximately 40 mg) per day .
• Approximately 6 to 12 weeks after initiating prednisone, the patient’s
symptoms, spirometry, lung volumes, and gas exchange (eg, diffusing
capacity [DLCO], arterial blood gases, pulse oxygen saturation at rest and on
exertion) are reassessed.
• Once a clinical response is noted, the dose of prednisone is tapered to 20
mg daily, or 40 mg on alternate days.

• Chest imaging may or may not demonstrate improvement.
• Evaluations are repeated at approximately three month intervals, and the
dose of prednisone is gradually tapered to the lowest level needed to
maintain physiologic and symptomatic improvement and disease stability,
usually about 5 to 10 mg daily.
• Complete withdrawal of prednisone can result in disease recrudescence, so
lifelong therapy is usually continued at the lowest dose of prednisone that
controls disease manifestations

TREATMENT FAILURE
• In some cases failure to respond was attributed to ongoing exposure to beryllium,
in others to delayed removal from exposure and delayed initiation of therapy .
• If no improvement in symptoms or physiologic parameters has occurred after six
months, a decision is made whether to discontinue glucocorticoid therapy or add
another immunosuppressive agent.
• If there has been a lag time of several years between the onset of symptoms and
initiation of therapy or if the chest radiograph and HRCT suggest a greater
proportion of fibrotic change, the patient likely does not have reversible disease
and glucocorticoid therapy can be tapered and stopped.
• If the clinical impression supports a greater likelihood of reversible disease, an
additional immunosuppressive agent is usually added.

OTHER IMMUNOSUPPRESSIVE
AGENTS
• For patients who fail to respond to glucocorticoids or who experience severe
side effects, addition of alternative immunosuppressive agents may be tried,
although clinical trials supporting their use have not been published.
• Based on the experience with low-dose methotrexate therapy for sarcoidosis,
this agent is often chosen for refractory CBD .
• Prior to initiating methotrexate, liver function tests and hepatitis B and C
viral antibody testing are obtained. Patients with evidence of underlying liver
disease or chronic infection with hepatitis B or C are not candidates for
methotrexate.

• Oral methotrexate is usually initiated at a starting dose of 7.5 mg weekly and
gradually increased (eg, by 2.5 mg increments every two weeks) until a dose
of 10 to 15 mg per week is achieved.
• folic acid 1 mg daily is routinely given to patients taking chronic low-dose
methotrexate therapy.
• Methotrexate toxicity includes liver inflammation and fibrosis, bone marrow
suppression, alopecia, skin rash, and teratogenicity.
• Complete blood counts and liver tests (eg, aminotransferases and albumin)
are repeated at 4 to 8 week intervals while escalating the dose and then at 8
to 12 week intervals.

• Azathioprine is another potential adjunctive therapy to
glucocorticoids, given some success with this agent in patients
with sarcoidosis . However, no published data is available to
support this choice.
• Based on the current understanding of immunopathogenesis of
CBD, tumor necrosis factor (TNF)-alpha antagonists appear
promising as therapeutic agents; however, definitive clinical trial
evidence supporting the use of these agents is not available and
results in sarcoidosis have been mixed.

PROGNOSIS
• The prognosis variability appears to depend on the industrial setting, the
duration of beryllium exposure after development of CBD, individual
variation, and the duration of clinical follow up .
• Among patients with beryllium sensitization without CBD (ie, a positive blood
BeLPT, but no lung pathology), the risk of progressing to CBD is clearly
increased, compared with non-sensitized workers.
• higher percentage of lymphocytes in the BAL correlates with a greater
severity of the illness

PREVENTION
• The permissible limit for occupational exposure to beryllium that was
designed to prevent CBD was 2 mcg/m 3 , as an eight hour time weighted
average.
• However, beryllium sensitization has been identified in approximately 10
percent of workers with lower exposures, leading to calls for lower
permissible exposure limits
• minimize occupational exposure to beryllium. improving ventilation systems
to reduce dust, minimizing the number of workers allowed into beryllium
areas, providing personal protective equipment (eg, respirators), and
educating workers in how to reduce the risk of exposure .
• Dermal exposure can also contribute to risk of beryllium sensitization;
therefore, measures should be taken to protect skin .

• Hard metal is an alloy of tungsten carbide in a matrix of cobalt into which
smaller amounts of chromium, nickel, niobium, tantalum, titanium, and/or
vanadium may be added.
• These components are milled to a fine powder, mixed together, pressed into
the desired shape, and heated under pressure to between 800 and 1000◦C,
yielding a product with a chalklike consistency.
• hard metal is an important component in cutting tools, drill bits, armor plate,
and jet engine parts.
• OSHA requires an 8-h of 0.1 mg/m3 as permissible exposure limits for
cobalt metal, dust, and fumes .

CLINICAL MANIFESTATIONS
• A variety of respiratory syndromes have been associated with exposure to
hard metal, most commonly:
(1) asthmatic reactions
(2) a form of hypersensitivity lung disease
(3) interstitial pulmonary fibrosis.
(4) Lung Cancer
• Hard-metal disease has been used to describe all types of lung disease but
is most often used to reference the parenchymal or interstitial lung disease
rather than the airway-related manifestations of hard-metal inhalations.

OCCUPATIONAL ASTHMA
• asthma can occur in workers exposed to cobalt alone without tungsten.
• Tungsten carbide has not been shown to produce bronchoconstriction.
• ranges from 6.5 percent to 10 percent.
• As with other forms of occupational asthma, patients may note cough,
wheezing, dyspnea, chest tightness, conjunctivitis, and rhinitis.

• Throughout the workday, symptoms may increase in severity, and a progressive
decline in peak flow may be demonstrated.
• Symptoms usually abate during weekends or vacations and often resolve when
exposure is discontinued.
• Upper-airway symptoms may result from either direct airway irritation or atopic
responses.
• the diagnosis may be confirmed by bronchoprovocation testing (BPT) with cobalt or
cobalt salts.
• Testing with cobalt salts is preferable, as it is much easier to control dosage and
delivery of soluble ion solutions than those of particulate substances.

• A positive radio-immunosorbent test (RAST) to cobalt-conjugated human
serum albumin has also been reported in some patients, suggesting a type I
allergic response.
• Skin patch testing with cobalt salts does not appear to be of use in
diagnosing hard-metal asthma.
• In patients with symptoms or findings suggestive of occupational asthma,
peak flow monitoring during working and nonworking hours should be
performed and other causes of pulmonary function deterioration ruled out.
• Treatment for occupational asthma related to cobalt includes control of
exposure as well as medical therapy with bronchodilators and inhaled
corticosteroids. Systemic corticosteroid treatment is usually not required.

INTERSTITIAL LUNG DISEASE
• ILD develops in a small minority of exposed workers. Estimates
range from 0.7 to 13 percent.
• Although ILD may occur after a short duration and low levels of
exposure, longer duration or higher levels of exposure are
associated with increased risk.
• Interestingly, most studies suggest that workers exposed to
cobalt alone without tungsten and other metals do not appear to
develop ILD.

• These patients manifest fever, anorexia, cough, dyspnea,
inspiratory crackles, and fine reticulonodular infiltrates on chest
radiograph.
• Pulmonary function testing typically shows a restrictive pattern,
with a reduced DlCO.
• Symptoms may resolve when exposure is discontinued but may
recur with re-exposure.
• Over time, progressive dyspnea, lung function impairment, and
interstitial fibrosis may develop.

• Fibrosis may also occur in the absence of antecedent
symptoms.
• Patients with advanced disease exhibit weight loss, hypoxemia,
digital clubbing, pulmonary hypertension, and corpulmonale.
• The histopathological manifestations of the interstitial disease in
these patients can be varied, with findings consistent with
bronchiolitis, desquamative interstitial pneumonitis, usual
interstitial fibrosis, and giant-cell interstitial pneumonitis (GIP).
• Granuloma formation does not occur.

• GIP is characterized by lympho-plasmacytic infiltration, epithelial
desquamation, and the presence of numerous multinucleated
giant cells in the alveolar spaces.
• These giant cells are formed by both actively phagocytic
alveolar macrophages and type II pneumocytes.
• Infiltration with eosinophils has also been described.
• Analysis of BALF may demonstrate hypercellularity, with
increased numbers of macrophages and giant cells.

• A relative or absolute increase in the number of lymphocytes,
with a reduced CD4/CD8 ratio as well as increased numbers of
neutrophils, eosinophils, and mast cells, may also be seen.
• Additionally, the multinucleated giant cells can also be found in
the BALF which can be diagnostic of hard metal lung disease
without requiring a surgical lung biopsy.
• Electron microscopy with energy dispersive x-ray analysis
(EDAX) of the particulate material present in biopsy specimens
may demonstrate the presence of the elements used to form
hard metal.

• CT findings of patients with hard-metal disease these findings show a wide
variability and can include end-stage honeycombing with cystic changes and
traction bronchiectasis, to less impressive reticulation and even areas of
ground-glass opacities.
• No pathognomonic finding has been described.
• Treatment for this disease consists of discontinuation of exposure and
administration of systemic corticosteroids.
• Although no clinical trials have been performed, dosage and duration of
treatment similar to those used in other forms of active alveolitis or fibrosis
should be considered.

• Patients with active alveolitis may show a dramatic response to
steroids, whereas patients with more prominent fibrosis may
show minimal response despite prolonged steroid treatment.
• Fibrosis can also progress despite cessation of exposure.
• GIP has been observed to recur after lung transplantation
despite cessation of occupational exposure.

LUNG CANCER
• there was inadequate evidence for the carcinogenicity of cobalt and cobalt
compounds in humans.
• Mechanisms of Injury
• (1) hypersensitivity with lymphocyte-driven toxicity
• (2) free-radical and cytokine-mediated injury.
• Bronchoalveolar lavage (BAL) studies of both exposed workers and those
with hardmetal disease have shown increased lymphocytes with reduction of
the helper/suppressor T-cell ratios.

Occupational lung diseases –general principles and approaches and beryllosis review

Occupational lung diseases –general principles and approaches and beryllosis review

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