Pulmonary sarcoidosis: population differences and pathophysiology

Sarcoidosis in residents of northern Israel of Arabic and Jewish origin: a comparative study

BACKGROUND

This study describes the features of sarcoidosis among Arab patients and compares it to Jewish patients residing in northern Israel.

METHODS

All new cases of biopsy-confirmed sarcoidosis diagnosed between 1980 and 1996 in northern Israel were divided into two groups according to their ethnic origin: Jewish (n = 72) and Arabic (n = 48). Disease parameters were recorded and compared.

RESULTS

Arabs and Jews had similar incidence rates that increased from 0.2/10(5) in 1980 to 2/10(5) per year in 1996. The peak incidence was in the sixth and seventh decades and the female/male ratio was 2 and 1.4 for Arabic and Jewish patients, respectively. Jewish patients had higher proportion stage II-IV pulmonary disease (78% vs. 51.2%) while their Arabic counterparts had higher proportion of stage I disease (70.8% vs. 41.7%). The proportion of extra-thoracic organ involvement was similar. Different disease phenotype indicated differed diagnostic procedures; higher proportion of mediastinoscopy for stage I disease among Arabic patients (47.9% vs. 20.8%, P = 0.015) and trans-bronchial biopsy for stage II-IV pulmonary disease among Jewish patients (25% vs. 8.35%, P = 0.05). Corticosteroids were used in a non-significantly higher proportion of Jewish patients (56.9% vs. 43.8%, P > 0.05). Of six sarcoidosis-related deaths (5%), five occurred in Jewish patients.

CONCLUSIONS

This study has documented different forms of presentation, clinical manifestation, severity and prognosis of sarcoidosis present among patients of Arabic and Jewish origin residing in the area of northern Israel.

Ultrastructural types of alveolar macrophages in bronchoalveolar lavages from patients with pulmonary sarcoidosis

By routine applied quantitative BAL methods are particularly helpful for the diagnosis of pulmonary sarcoidosis. Here the morphology of the alveolar cells does not play a role. However, morphological and especially electron microscopic investigations might contribute to the clarification of the aetiology of this disease. In a prospective study we investigated the bronchoalveolar lavages (BALs) from 10 patients with recently histologically diagnosed, untreated pulmonary sarcoidosis. Commonly applied cytological and immunological BAL diagnostic techniques were accompanied by morphological investigations of alveolar cells, especially alveolar macrophages, using light and electron microscopy. All patients showed lymphocytic alveolitis with an increased number of CD4 positive lymphocytes as well as an increased CD4/CD8 ratio. A striking light microscopic finding was the great morphological variety of the alveolar macrophages. Electron microscopy revealed typical lymphocytes, neutrophils, and eosinophils as well as three different types of alveolar macrophages in all 10 patients: type I (approx. 30%) with a normal macrophage morphology, a vacuole-rich type II (approx. 30%) with myelin-like structures and type III (approx. 40%) with electron-dense inclusions. The occurrence of intracellular myelin figures in type II macrophages is a hint for increased phagocytotic processes of surfactant with or without its overproduction in the sense of a secondary alveolar proteinosis. Numerous electron-dense inclusions in type III also indicate an increased macrophage activity that leads to an increased release of cytokines, which in turn can trigger an inflammatory reaction.

Bronchoalveolar lavage fluid D dimer levels are higher and more prevalent in black patients with pulmonary sarcoidosis

BACKGROUND

Abnormalities of lung coagulation and fibrinolysis in sarcoidosis are thought to play a role in the pathogenesis of this disease.

OBJECTIVE

We previously showed that bronchoalveolar lavage fluid (BALF) D dimer directly correlated with various measures of severity in sarcoidosis. Here, we analyze our observation that BALF D dimer was more frequently found at higher levels in African-American patients with pulmonary sarcoidosis.

METHODS

BALF D dimer was measured in 55 subjects with pulmonary sarcoidosis and 31 healthy volunteers by enzyme immunoassay. The healthy group established a normal range of BALF D dimer with 71 ng/ml as the highest measured level. This was the cut point for comparisons among the patients with sarcoidosis.

RESULTS

High BALF D dimer levels (>71 ng/ml) were found in younger patients with sarcoidosis and were associated with a significantly lower percent predicted forced expiratory volume in 1 s and greater numbers of BAL lymphocytes. Black patients with sarcoidosis had higher BALF D dimer levels (median 131, range 0-2,040 ng/ml) than white patients (median 18, range 0-605 ng/ml; p = 0.011). Higher than normal BALF D dimer levels were found in 61% of the black subjects with sarcoidosis, but in only 20% of the white individuals (chi(2) = 5.539, p = 0.019). BALF D dimer was the only disease measure that discriminated black from white individuals with sarcoidosis.

CONCLUSION

BALF D dimer is an indicator of lung fibrin formation and degradation in sarcoidosis. The relationship of high D dimer levels with greater BAL lymphocytosis and worse lung function may be a marker of active sarcoidosis, especially in African-Americans who tend to suffer a more serious form of the disease.

Differential effects of fosfomycin and corticosteroid on the molar ratio of interleukin-1 receptor antagonist/interleukin-1β in the culture supernatants of mononuclear phagocytes from patients with sarcoidosis

We compared the effects of fosfomycin, an antibiotic reported to possess immunomodulatory activities, and prednisolone on the production of interleukin-1 receptor antagonist (IL-1ra) and IL-1beta by bronchoalveolar lavage fluid (BALF) macrophages obtained from sarcoidosis patients. The molar IL-1ra/IL-1beta ratio in the culture supernatants of BALF macrophages obtained from sarcoidosis patients, which was lower in sarcoidosis patients than in healthy nonsmokers, was significantly increased in the presence of fosfomycin, but decreased by prednisolone. Further, the molar IL-1ra/IL-1beta ratios in the culture supernatants of peripheral blood mononuclear cells isolated from four of five patients after fosfomycin administration for 14 days were higher than the ratios measured before fosfomycin administration. Fosfomycin showed an anti-inflammatory effect in a different way, when compared with that of prednisolone.

The incidence, prevalence, and severity of sarcoidosis in New York City firefighters

OBJECTIVE

The etiology of sarcoidosis is unknown, but epidemiology suggests that environmental agents are a factor. Because firefighters are exposed to numerous toxins, we questioned whether sarcoidosis was increased in this cohort.

SETTING

The New York City Fire Department (FDNY), employing > 11,000 firefighters and nearly 3,000 emergency medical services (EMS) health-care workers (HCWs).

DESIGN

In 1985, FDNY initiated a surveillance program to determine the incidence, prevalence, and severity of biopsy-proven sarcoidosis in firefighters. In 1995, EMS HCWs were added as control subjects.

RESULTS

Between 1985 and 1998, 4 prior cases and 21 new cases of sarcoidosis were found in FDNY firefighters. Annual incidence proportions ranged from 0 to 43.6/100,000, and averaged 12.9/100,000. On July 1, 1998, the point prevalence was 222/100,000. For EMS HCWs, annual incidence proportions were zero. Radiographic stage 0 or stage 1 sarcoidosis was found in 19 firefighters (76%), and stage 3 was found in 1 firefighter (4%). Pulmonary function (FVC, FEV(1), and diffusing capacity for carbon monoxide) was normal in 17 firefighters (68%), and reduced to </= 65% predicted in 2 firefighters (8%). Maximum oxygen consumption (MVO(2)) was normal in 10 of 17 firefighters (59%), and reduced to 65% predicted in 3 firefighters (12%). Five of seven firefighters (71%) with abnormal MVO(2) had gas exchange abnormalities, and none had O(2) desaturation. All returned to fire fighting.

CONCLUSIONS

Annual incidence proportions and point prevalence were increased in FDNY firefighters as compared to EMS HCWs and historical controls. Radiographs and physiologic measurements demonstrated only minimal impairment.

Bronchoalveolar lavage. Still useful in diagnosing sarcoidosis?

BALF parameters, if evaluated as a diagnostic or prognostic tool, should be based on a full understanding of the clinical profiles and course of pulmonary sarcoidosis. The various markers that have been reported so far are unreliable in determining the prognosis, although BALF lymphocytes and CD4/CD8 ratios are still useful for diagnosing sarcoidosis. It is critical to find feasible markers that relate to a change in disease activity and prognosis, because markers of chronicity may be different from those of progressively worsening sarcoidosis.