A case control etiologic study of sarcoidosis: environmental and occupational risk factors

Infliximab Therapy in Patients with Chronic Sarcoidosis and Pulmonary Involvement

RATIONALE

Evidence suggests that tumor necrosis factor (TNF)-alpha plays an important role in the pathophysiology of sarcoidosis.

OBJECTIVES

To assess the efficacy of infliximab in sarcoidosis.

METHODS

A phase 2, multicenter, randomized, double-blind, placebo-controlled study was conducted in 138 patients with chronic pulmonary sarcoidosis. Patients were randomized to receive intravenous infusions of infliximab (3 or 5 mg/kg) or placebo at Weeks 0, 2, 6, 12, 18, and 24 and were followed through Week 52.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the change from baseline to Week 24 in percent of predicted FVC. Major secondary efficacy parameters included Saint George's Respiratory Questionnaire, 6-min walk distance, Borg's CR10 dyspnea score, and the proportion of Lupus Pernio Physician's Global Assessment responders for patients with facial skin involvement. Patients in the combined infliximab groups (3 and 5 mg/kg) had a mean increase of 2.5% from baseline to Week 24 in the percent of predicted FVC, compared with no change in placebo-treated patients (p = 0.038). No significant differences between the treatment groups were observed for any of the major secondary endpoints at Week 24. Results of post hoc exploratory analyses suggested that patients with more severe disease tended to benefit more from infliximab treatment.

CONCLUSIONS

Infliximab therapy resulted in a statistically significant improvement in % predicted FVC at Week 24. The clinical importance of this finding is not clear. The results of this Phase 2 clinical study support further evaluation of anti-TNF-alpha therapy in severe, chronic, symptomatic sarcoidosis.

Antifungal treatment in sarcoidosis--a pilot intervention trial

BACKGROUND

Sarcoidosis is generally treated with corticosteroids that are not always an effective therapy.

OBJECTIVES

To assess if treatment with antifungal drugs would improve the clinical status of patients with sarcoidosis.

METHODS

Patients (n=18) with sarcoidosis grades II and III according to established criteria and without clinical and immunological signs of fungal infection, were treated with antifungal medication together with corticosteroids for 3-6 months. Pulmonary X-ray infiltration, lung function, and severity of symptoms were registered before and after the treatment and at follow up 9-58 months later.

RESULTS

The treatment resulted in statistically significant decreases in the degree of pulmonary infiltration with an average decrease in the group from 2.0 to 1.0. There were also significant increases in diffusion capacity and decreases in the severity of symptoms.

CONCLUSION

It is suggested that treatment with antifungal drugs may be useful, at least in certain cases of sarcoidosis.

Genetic characterization and fine mapping of susceptibility loci for sarcoidosis in African Americans on chromosome 5

Sarcoidosis, a systemic granulomatous disease, likely results from both environmental agents and genetic susceptibility. Sarcoidosis is more prevalent in women and, in the United States, African Americans are both more commonly and more severely affected than Caucasians. We report a follow up of the first genome scan for sarcoidosis susceptibility genes in African Americans. Both the genome scan and the present study comprise 229 African American nuclear families ascertained through two or more sibs with sarcoidosis. Regions studied included those which reached a significance in the genome scan of 0.01 (2p25, 5q11, 5q35, 9q34, 11p15 and 20q13), 0.05 (3p25 and 5p15-13) or which replicated previous findings (3p14-11). We performed genotyping with additional markers in the same families used in the genome scan. We examined multi-locus models for epistasis and performed model-based linkage analysis on subsets of the most linked families to characterize the underlying genetic model. The strongest signal was at marker D5S407 (P=0.005) on 5q11.2, using both full and half sibling pairs. Our results support, in an African American population, a sarcoidosis susceptibility gene on chromosome 5q11.2, and a gene protective for sarcoidosis on 5p15.2. These fine mapping results further prioritize the importance of candidate regions on chromosomes 2p25, 3p25, 5q35, 9q34, 11p15 and 20q13 for African Americans. Additionally, our results suggest joint action of the effects of putative genes on chromosome 3p14-11 and 5p15.2. We conclude that multiple susceptibility loci for sarcoidosis exist in African Americans and that some may have interdependent effects on disease pathogenesis.

Retrograde radiographic development in pulmonary sarcoidosis

A 48-year-old man with dyspnea, cough, and fever was found to have a diffuse ground-glass pulmonary lesion without lymphadenopathy on chest X-ray. The lesion shifted to the peripheral lung zones 2 months later when transbronchial biopsy demonstrated noncaseating granulomas with Langhans type giant cells. After 6 more months, prominent bilateral hilar lymphadenopathy and highly elevated serum angiotensin-converting enzyme confirmed the diagnosis of pulmonary sarcoidosis. Such a course is quite rare in that it goes the opposite way of the conventional staging system.

Recurrent sarcoidosis in lung transplant allografts: granulomas are of recipient origin

INTRODUCTION

Sarcoidosis accounts for only 2.8% of lung transplants in the United States. It is, however, the most commonly reported disease to recur after lung transplantation. In most cases, recurrence is diagnosed as an incidental finding in transbronchial lung allograft biopsy (TBLAB) and is unrelated to clinical or radiologic abnormalities. The origin of the histiocytes composing the noncaseating granulomas in the allograft lung in patients with recurrent sarcoidosis (RS) was analyzed using DNA identity testing in 4 cases.

MATERIAL AND METHODS

Native lung resections and corresponding transbronchial biopsies from patients who underwent lung transplantation for sarcoidosis between 1990 and 2004 and who developed RS were gathered from the paraffin block archives of University of Pittsburgh Medical Center. Clinical parameters including age, sex, grade of rejection, number of episodes of RS, and follow-up were recorded. Native lungs and corresponding TBLAB showing granulomas consistent with RS were microdissected in cases where adequate material was available. DNA was extracted, and an ABI AmpflSTR commercial kit was used to simultaneously amplify 15 short tandem repeat (STR) loci as well as 1 marker for the XY chromosomes. The informative STR loci in native lung (pure recipient), nongranulomatous donor lung, and granulomas in donor lung were analyzed in 4 patients. The relative proportion of donor and recipient cells in the chimera was quantified using the fluorescence intensity of each peak on an electropherogram. FISH analysis using probes targeted to X and Y chromosomes was performed in a case of sex-mismatched lung transplantation.

RESULTS

Eight patients with RS were identified. Two had bilateral lung transplantation, and the remaining 6 had single-lung transplantation. The age at transplantation ranged between 39 and 53. Five were females and 3 were men. Recurrent disease was diagnosed in 1 to 11 biopsies per patient and occurred first in the first 6 months following transplantation in 2 cases (25%), between 6 months and 1 year in 2 other cases (25%), and between 1 and 2 years in 4 cases (50%). In 4 patients, sufficient material allowed for DNA analysis. Amplification failed in 1 of the 4 cases, while the other 3 were successful. Patient 1 showed no ACR and granulomatous inflammation of RS in TBLAB. Donor (D) to recipient (R) profile changed from "normal" donor lung (37% D, 63% R) to 15% D and 85% R DNA in the granuloma. In patient 2, the TBLAB showed minimal ACR and granulomatous inflammation. D to R profile changed from 75% D and 25% R in the "normal" D lung to 54% D and 46% R in the granuloma. Patient 3 showed no ACR and RS in TBLAB. D to R profile changed from 85% D and 15% R in the "normal" D lung to 71% D and 29% R in the granuloma. FISH analysis showed a predominance of male cells of recipient origin.

CONCLUSIONS

DNA analysis of 3 cases of RS suggests that the presence of recurrent granulomas in the graft is associated with an increase in the percentage of recipient DNA in the epithelioid cell clusters, as confirmed by the FISH analysis of 1 case.

Sarcoidosis

Sarcoidosis is a disease found in most populations worldwide, although it has a proclivity for relatively young African-American women in the United States. Although the pathogenesis is unknown, there likely are social, environmental, and genetic factors that are involved. Sarcoidosis seems to be different between whites and African Americans, with the latter population experiencing more severe and chronic disease. Improving access to care and addressing other disparities in health care may help to bridge the gap in health outcomes observed between patients.

Job and industry classifications associated with sarcoidosis in A Case-Control Etiologic Study of Sarcoidosis (ACCESS)

OBJECTIVES

To determine whether specific occupations and industries may be associated with sarcoidosis.

METHODS

A Case Control Etiologic Study of Sarcoidosis (ACCESS) obtained occupational and environmental histories on 706 newly diagnosed sarcoidosis cases and matched controls. We used Standard Industrial Classification (SIC) and Standard Occupational Classification (SOC) to assess occupational contributions to sarcoidosis risk.

RESULTS

Univariable analysis identified elevated risk of sarcoidosis for workers with industrial organic dust exposures, especially in Caucasian workers. Workers for suppliers of building materials, hardware, and gardening materials were at an increased risk of sarcoidosis as were educators. Work providing childcare was negatively associated with sarcoidosis risk. Jobs with metal dust or metal fume exposures were negatively associated with sarcoidosis risk, especially in Caucasian workers.

CONCLUSIONS

In this study, we found that exposures in particular occupational settings may contribute to sarcoidosis risk.

[Update on sarcoidosis]

Since the first description more than a century ago, intensive research continues to focus on sarcoidosis. Based on our current knowledge, sarcoidosis can be considered as an immune syndrome resulting from a variable combination of predisposing genetic, ethnic, and environmental factors. Over the last few years, several teams have proposed a link between certain genetic polymorphisms, particularly of the HLA system, and the risk of development or progression of sarcoidosis. Other pathogenic mechanisms involved in the formation of the sarcoid granuloma are becoming more clear and have led to the development of new therapeutic approaches such as anti-TNF currently being evaluated in multicentric trials.