Immunology of sarcoidosis

Successful treatment of recalcitrant cutaneous sarcoidosis with fumaric acid esters

BACKGROUND

Sarcoidosis is a multisystem disease of unknown origin characterized by the formation of noncaseating granulomas, in particular in the lungs, lymph nodes, eyes, and skin. Systemic treatment for cutaneous sarcoidosis can be used for large disfiguring lesions, generalized involvement, or recalcitrant lesions that did not respond to topical therapy.

CASE PRESENTATIONS

We report three patients with recalcitrant cutaneous sarcoidosis who were treated with oral fumaric acid esters (FAE). Three female patients presented with cutaneous sarcoidosis that have proved to be refractory to various therapies, including corticosteroids and chloroquine. We treated the patients with FAE in tablet form using two formulations differing in strength (Fumaderm initial, Fumaderm). Dosage of FAE was performed according to the standard therapy regimen for psoriasis patients. After treatment with FAE (4-12 months), a complete clearance of skin lesions was achieved in the three patients. The side effects observed in this trial correspond to the well-known spectrum of adverse effects of FAE (flush, minor gastrointestinal complaints, lymphopenia).

CONCLUSIONS

On the basis of our findings FAE therapy seems to be a safe and effective regimen for patients with recalcitrant cutaneous sarcoidosis. Nevertheless further investigations are necessary to confirm our preliminary results.

Outcomes for patients with sarcoidosis awaiting lung transplantation

STUDY OBJECTIVES

To describe the population of patients with sarcoidosis listed for orthotopic lung transplantation (OLT) in the United States, and to determine outcomes for these subjects relative to persons awaiting OLT for idiopathic pulmonary fibrosis (IPF).

DESIGN

Retrospective analysis of the United Network for Organ Sharing transplant database over the period between January 1995 and December 2000.

PATIENTS

All patients listed for OLT with an underlying diagnosis of either sarcoidosis or IPF.

MEASUREMENTS AND RESULTS

During the study period, 427 patients with sarcoidosis and 2,115 patients with IPF were registered on the list for OLT. Demographically, the patients with sarcoidosis were younger and more likely to be female African Americans than were patients with IPF. Pulmonary function was worse in patients with sarcoidosis. The mean FVC was 42.6% of predicted, as compared to 45.0% of predicted in patients with IPF (p = 0.0044). The FEV(1) also differed between the populations (36.0% vs 46.0% of predicted for patients with sarcoidosis and IPF, respectively; p < 0.0001). Only 30.1% of patients with sarcoidosis and 32.4% of patients with IPF lacked functional limitations. For the subset of patients with hemodynamic data available, the mean pulmonary artery pressure was significantly higher in the sarcoidosis population (34.4 mm Hg vs 25.6 mm Hg, respectively; p < 0.0001). Neither the pulmonary capillary wedge pressure nor the cardiac index differed between the groups. Patients with sarcoidosis were less likely to receive a transplant. Approximately 30% of patients with sarcoidosis underwent OLT, compared to 37.3% of IPF patients (p = 0.0102). For those who did undergo transplantation, the median wait until OLT was 803 days for patients with sarcoidosis compared to 555 days for patients with IPF (p < 0.0001). Mortality rates were similar in both groups. In the sarcoidosis group, 28.1% of patients died, compared to 31.1% of patients with IPF (p = not significant).

CONCLUSIONS

Patients with sarcoidosis are at as high a risk for mortality as patients with IPF while awaiting transplantation. Nonetheless, patients with sarcoidosis are less likely to undergo OLT. Pulmonary hypertension is a major concern in patients with advanced sarcoidosis awaiting transplantation.

Delayed cutaneous hypersensitivity tests and lymphopenia as activity markers in sarcoidosis

STUDY OBJECTIVES

To evaluate new and already known biological markers of activity in patients with sarcoidosis.

DESIGN

A 10-year prospective clinical evaluation, including a battery of delayed cutaneous hypersensitivity tests (DCHTs) and other markers of activity.

SETTING

Outpatient department of a university teaching hospital.

PATIENTS

Forty patients with biopsy-proven sarcoidosis were prospectively evaluated every 6 months. In this study, only the visits that fulfilled the situation of active period (AcP) or of asymptomatic period (AsP) were taken into account. Twenty-one visits were considered to be in the AcP, and 26 were considered to be in the AsP. Seven patients were studied both in the AcP and the AsP.

INTERVENTIONS

DCHTs and blood sample extraction every 6 months.

MEASUREMENTS AND RESULTS

The mean diameter of the cutaneous wheal for each antigen (AG) was lower in the AcP group than in the AsP group (candidine, p < 0.0001; tuberculin, p < 0.0009; trichophytin, p < 0.02; streptokinase-streptodornase, p < 0.001). Also, the mean (+/- SD) diameter for the four AGs taken together was lower in the AcP group (2.3 +/- 4.2 mm) than in the AsP group (16.8 +/- 9.3 mm; p < 0.0001). The mean serum angiotensin-converting enzyme (S-ACE) value was higher in the AcP group than in the AsP group (p < 0.02). A low lymphocyte count and a percentage of the lymphocyte count (< 20%) also were detected more frequently in the AcP group than in the AsP group (p < 0.02 and p < 0.0001, respectively).

CONCLUSIONS

DCHTs appear to be a simple, reliable, and easily performed marker of inflammatory activity in sarcoidosis patients. Furthermore, serum total and differential lymphocyte count and the S-ACE level proved to be useful inflammatory markers in this study.

Nerve granulomas and vasculitis in sarcoid peripheral neuropathy: a clinicopathological study of 11 patients

Peripheral neuropathy is a rare, yet treatable manifestation of sarcoidosis, a multisystem disorder characterized by the presence of non-caseating granulomas that are seldom found in nerve biopsy specimens. In order to learn more about the subject, we reviewed our clinical and pathological findings in a series of 11 patients (six men and five women aged 26-83 years) with symptomatic neuropathy associated with characteristic granulomas in nerve biopsy specimens. Only two patients were known to have sarcoidosis before the occurrence of the neuropathy. The neuropathy was focal or multifocal in six patients, including one with a multifocal neuropathy associated with conduction blocks, and one with a multifocal axonal motor deficit. Four patients had a distal symmetrical deficit and one patient had a Guillain-Barré-like syndrome with facial diplegia and respiratory failure. Serum angiotensin-converting enzyme concentration was elevated in only two patients. Epineurial granulomas and perineuritis were present in all nerve specimens. The inflammatory infiltrates invaded the endoneurium, following connective tissue septae and blood vessels, in five patients. Multinucleated giant cells were found in eight patients and necrotizing vasculitis in seven. Inflammatory lesions were associated with variable, asymmetrical involvement of nerve fascicles and axon loss. A muscle specimen was sampled during the same procedure in 10 patients. It showed inflammatory infiltrates and granulomas in nine patients and necrotizing vasculitis in two. Immunolabelling showed a mixed inflammatory infiltrate of T cells (predominantly CD4+ cells) and macrophages, in keeping with a delayed hypersensitivity reaction. In addition to nerve involvement, all patients had at least one other tissue or organ affected, including muscle in nine patients, lungs and/or intrathoracic lymph nodes in eight, skin in three, arthritis in two, and peripheral lymph nodes, stomach and eye in one patient each. Most patients improved on corticosteroids. Two patients remain free of symptoms after 7 years. Severe side-effects of long-term treatment with corticosteroids occurred in two patients, leading to death in one. This study illustrates the wide range of clinical manifestations of sarcoid neuropathy and the frequent association of granulomatous inflammatory infiltrates with necrotizing vasculitis and with silent or symptomatic involvement of other organs.

Neurologic manifestations of sarcoidosis

Sarcoidosis is multisystem granulomatous disease of unknown etiology. Although the nervous system is involved in only 5% to 16% of patients, neurosarcoidosis is one of the more serious manifestations of the disease. Cranial neuropathies are common, but involvement of the mininges or the brain or spinal cord parenchyma causes more severe morbidity. MR imaging of affected portions of the neuraxis is a very sensitive diagnostic technique. Treatment with corticosteroids is the mainstay of therapy.

Endobronchial biopsy for sarcoidosis: a prospective study

STUDY OBJECTIVES

To determine the yield of endobronchial biopsy (EBB) for suspected sarcoidosis, and to evaluate if EBB increases the diagnostic value of fiberoptic bronchoscopy (FOB) when added to transbronchial biopsy (TBB).

DESIGN

Prospective study of consecutive patients.

SETTING

Pulmonary clinic of a tertiary-care, academic medical center.

PATIENTS

Patients consecutively referred for suspected pulmonary sarcoidosis.

INTERVENTIONS

All patients having FOB performed underwent an evaluation that included history, physical examination, a chest radiograph, and spirometry. During FOB, airway appearance was recorded and both TBB and EBB were performed in a standardized fashion. Six TBB specimens were obtained, as were six EBB samples. For patients with abnormal-appearing airways, four specimens were obtained from the abnormal-appearing airways and two specimens were obtained from the main carina. In patients with normal-appearing airways, four specimens were obtained from a secondary carina and two specimens were obtained from the main carina. A biopsy finding was considered positive if it demonstrated nonnecrotizing granulomas with special stains that were negative for fungal and mycobacterial organisms.

MEASUREMENTS AND RESULTS

The study cohort included 34 subjects (mean +/- SD age, 37.9 +/- 6.8 years; 58.8% were male; 64.7% were African American). EBB findings were positive in 61.8% of patients, while TBB showed nonnecrotizing granulomas in 58.8% of subjects. The addition of EBB increased the yield of FOB by 20.6%. Although EBB findings were more frequently positive in abnormal-appearing airways (p = 0.014), EBB provided diagnostic tissue in 30.0% of patients with normal-appearing endobronchial mucosa. There were no complications resulting from the addition of EBB to TBB.

CONCLUSIONS

Endobronchial involvement is common in sarcoidosis. EBB has a yield comparable to TBB and can safely increase the diagnostic value of FOB. Pulmonologists should consider routinely performing EBB in cases of suspected sarcoidosis.

Clinical insights and basic science correlates in sarcoidosis

More than a century has elapsed since the initial description of sarcoidosis, but critical aspects of the disorder remain poorly understood. Information obtained from epidemiologic observations and basic laboratory research suggests that the disease may represent an immunologic response to an exogenous agent in a genetically susceptible individual. However, a definitive etiologic role for any specific exogenous agent has never been proved, and a "candidate gene" underlying a predisposition to sarcoidosis has not yet been identified. This review presents an historical framework for considering available evidence regarding a transmissible agent in sarcoidosis and host susceptibility to the disease.

Non-caseating granulomata associated with hypocellular myelodysplastic syndrome

Non-caseating granuloma (NCG) remains a histopathological hallmark for sarcoidosis. Although the exact mechanism for NCG formation is unknown, the pathogenesis may involve a disordered antigen presentation in the monocyte/macrophage system, functional abnormalities in activated T-lymphocytes and uncontrolled cytokine production. Similar immunological dysfunction has been described in myelodysplastic syndrome (MDS). However, the association of NCG and MDS is rarely documented. We report a case of hypocellular MDS associated with generalized NCG. Despite treatment for both sarcoidosis and tuberculosis, the patient failed to respond. A clonal myeloid disorder which was initially suppressed by T-cell immunosurveillance evolved after treatment with anti-thymocyte globulin. Although the coexistence of sarcoidosis remains a possibility, the lack of supportive clinical evidence of sarcoidosis, the abnormal appearances of the bone marrow, together with the failure to improve on high-dose steroid favour the clonal myeloid disorder as the sole pathology.

Sarcoid and erythema nodosum arthropathies

Sarcoidosis is a systemic granulomatous disease of unknown origin, characterized in affected organs by an accumulation of activated T lymphocytes and macrophages. Musculoskeletal manifestations of sarcoidosis include acute and chronic arthritis and muscular and osseous sarcoidosis. In certain populations, acute sarcoidosis often presents with constitutional symptoms, polyarthritis and erythema nodosum (Löfgren's syndrome). Erythema nodosum, often with joint symptoms, also occurs in association with several other conditions including infections, medications and other underlying diseases. The diagnosis of sarcoidosis should be based on a tissue biopsy, but a patient with typical Löfgren's syndrome may not require biopsy proof. Among the long list of biochemical markers that have been suggested as aids for diagnosis and monitoring of sarcoidosis, calcium in serum and urine and angiotensin-converting enzyme in serum are well-established clinical tools. Serum angiotensin-converting enzyme can be used for monitoring disease activity in the individual patient, but because of lack of sensitivity and specificity its diagnostic value is rather low. Non-steroidal anti-inflammatory agents usually effectively alleviate acute sarcoid arthritis and joint symptoms associated with erythema nodosum. In severe acute arthritis and in chronic arthritis, corticosteroids may be required to control the symptoms. In patients requiring persistent corticosteroid therapy, antimalarial agents and methotrexate constitute therapeutic alternatives.

Sarcoidosis in developing countries

Sarcoidosis is seen in different parts of India and other developing countries with almost similar frequency as in the West. It was largely due to lack of awareness and non-availability of investigations for diagnosis that the disease was reported to be rare in the past. A combination of clinical, radiologic, and histologic criteria are used to diagnose sarcoidosis. A confident exclusion of other causes of granuloma formation, especially tuberculosis, is required. Absence of mycobacteria and of caseation in the histologic specimens and presence of skin anergy to tuberculin help make a diagnosis. Transbronchial lung biopsy obtained with the help of fiberoptic bronchoscopy is positive in about 80% of patients. Corticosteroids are used to treat patients with symptoms and those showing active organ involvement. Aggressive treatment is required for patients with acute and severe pulmonary, cardiac, ocular, or neurologic involvements.

Sarcoidal tissue reaction in Sézary syndrome

Sézary syndrome (SS) is an erythrodermic and leukemic variant of cutaneous T-cell lymphoma (CTCL). Occasionally, the histology of CTCL exhibits evidence of a granulomatous infiltrate in the skin. A case of SS that showed epithelioid granulomas resembling sarcoidosis in the skin and lymph nodes is presented. The clinical course of this patient has been relatively indolent.

Renal sarcoidosis with superimposed postinfectious glomerulonephritis presenting as acute renal failure

We describe two patients with sarcoidosis with lesions of granulomatous interstitial nephritis (GIN) and postinfectious glomerulonephritis (GN). Both patients presented with heavy proteinuria, hematuria, and renal failure. Renal histology in both showed GIN and glomerular changes of proliferative GN with hump-like subepithelial deposits by electron microscopy of postinfectious GN. Antecedent history of pneumonia was present in one, and ASO titer was elevated in the other. The proteinuria and azotemia improved in both with steroid therapy. Reports of "postinfectious" or diffuse proliferative GN in patients with sarcoidosis are rare. The authors are unaware of reports of concomitant sarcoid GIN and postinfectious GN. Although acute renal insufficiency or failure can occur with GIN or other more common renal lesions primary glomerular disease should be considered in patients with sarcoidosis who present with renal dysfunction. This is a US government work. There are no restrictions on its use.

Hepatic granulomas and hepatic sarcoidosis

The causes of hepatic granulomas are numerous and their identification can be difficult. Sarcoidosis is a main cause of hepatic granulomas. The mechanisms that initiate the formation of sarcoid granulomas are unknown. This article discusses the pathology of hepatic sarcoidosis and hepatic granulomas.

Novel aggregate structure adjuvants modulate lymphocyte proliferation and Th1 and Th2 cytokine profiles in ovalbumin immunized mice

Cytokines are important mediators of effector lymphoid cell function during an immune response. The principal cytokine producers are the T helper (Th) cells and macrophages. Vaccine strategies need to take into account the balance of Th (Th1/Th2) cytokines they induce. Adjuvants are compounds that, when combined with an antigen, potentiate an immune response in an immunized species. The use of adjuvants has been shown to activate differentially Th1 and Th2 subsets. In this study we describe the immunopotentiating properties of three novel molecular aggregate formulations based on tomatine (RAM1), a glycosylamide lipid (RAM2) and a fifth generation dendrimeric polymer (RAM3) respectively. These formulations were evaluated for their ability to augment Th1 or Th2 cytokine responses when administered with a soluble protein antigen. Of the three formulations, RAM1 was found to induce predominantly Th1 cytokines; the levels of which were substantially higher than those induced by reference control adjuvants. It was also found that at a late post-vaccinated period, RAM1 can stimulate Th2 responses. In contrast, RAM2 and RAM3 induced cytokine profiles typically associated with Th2 responses.

The clinical management of sarcoidosis. A 50-year experience at the Johns Hopkins Hospital

Sarcoidosis is an enigmatic disease with extremely variable manifestations in pattern, severity and course. Since Longcope and Freiman's descriptive monograph in 1952 (50) summarizing the clinical findings of the first half of this century, new dimensions of assessing the disease and treatment have been added. The impact of corticosteroids is central. The present review extends the studies to the second half of this century. Earlier diagnosis is facilitated and treatment often reverses many of the disease manifestations and improves the quality and extent of life for the patient. The management issues and guidelines outlined in this paper for both intrathoracic and extrathoracic disease are based on several longitudinal studies of the sarcoidosis patients summarized here, and 50 years of clinical experience by the senior author (CJJ) at Johns Hopkins Hospital, a tertiary referral center with an active Sarcoid Clinic. Case reports are presented in the appendix. It is clear that corticosteroids are the most effective therapeutic agent for sarcoidosis, usually with impressive and prompt response. This represents the dramatic difference in this disease after 1950. No more specific or effective immunosuppressive or antiinflammatory agents have been identified. Undesirable side effects are minimal if excessive doses are avoided. The effectiveness of "steroid-sparing agents" such as methotrexate is uncertain. Although irreversible tissue damage from the disease may limit the effectiveness of treatment, benefits of corticosteroids greatly exceed the negative side effects. Since spontaneous remissions without treatment do occur, a period of observation of 2 years are more is warranted if the patient is relatively asymptomatic. Gradual radiographic progression for 2 or more years, even without major symptoms or reduction in pulmonary function, indicates the need for a trial of corticosteroid treatment, especially in white patients where symptoms may lag behind the radiographic changes. Relapses as treatment is withdrawn are frequent, especially in African-American patients, who tend to have more severe and more prolonged disease than white patients. A minimum of 1 year of treatment is recommended unless no improvement is noted after 3 months. Continued low-dose prednisone at daily doses of 10-15 mg is helpful in preventing relapses and further progression of disease. Periodic attempts at tapering are justified. Repeated relapses may indicate the need for life-long treatment. When irreversible changes are present, especially in the presence of chronic fibrotic disease, changing goals of treatment to provide optimal supportive care may represent better management than having unrealistic expectations from increased corticosteroid dosage or the addition of other potentially toxic immunosuppressive agents. Many agents related to sarcoidosis require further research. The most important question facing sarcoid researchers today is etiology. It is difficult to design specific therapy when the fundamental causes and disease mechanisms are not established. Rather than being a single disease with a single cause, it is possible that a number of genetic factors and environmental or infectious agents may result in an immune response that is manifested as sarcoidosis. Understanding basic causal mechanisms may help explain the varied disease manifestations and aid in designing curative treatments. Such etiologic questions should be explored from both a basic science and an epidemiologic approach. Therapeutic trials of new drugs such as pentoxyfylline and possibly thalidomide are needed to address their potential as well as limitations of steroid therapy. Finally, for patients who have progressed to organ failure, the problems of sarcoid recurrence in transplanted tissue, increased allograft rejection, and long-term prognosis of solid organ transplants have yet to be resolved. (ABSTRACT TRUNCATED)

Osteopontin Is Associated with T Cells in Sarcoid Granulomas and Has T Cell Adhesive and Cytokine-Like Properties In Vitro

Sarcoidosis is a systemic disease characterized by the accumulation of activated T cells and widespread granuloma formation. In addition, individual genetic predisposition appears to be important in this disease. Osteopontin, a noncollagenous matrix protein produced by macrophages and T lymphocytes, is expressed in the granulomas of tuberculosis, and is associated with genetic susceptibility to intracellular infection. The function of osteopontin in these T cell-mediated responses is unknown. We sought to elucidate the role of osteopontin in granulomatous inflammation by characterizing its expression in different stages of sarcoidosis and its effector function on T cells in vitro. Lymphocyte-associated expression of osteopontin in sarcoidosis was demonstrated by immunohistochemistry, and its expression correlated with granuloma maturity. In addition, osteopontin induced T cell chemotaxis, supported T cell adhesion (an effect enhanced by thrombin cleavage of osteopontin), and costimulated T cell proliferation. These results suggest a novel mechanism by which osteopontin and thrombin modulate T cell recruitment and activation in granulomatous inflammation.

Update on sarcoidosis

The local inflammatory response in sarcoidosis appears to be a Th1-mediated process. Evidence exists that the systemic immune response, however, shows a Th2 predominance. Mycobacteria species, particularly cell wall-deficient forms, continue to be candidates for an infectious cause of the disease. Evidence for a possible role for human herpesvirus 8 has also been submitted. The relationship between sarcoidosis and infectious pathogens remains open to investigation. Both Sjögren's syndrome and common variable immunodeficiency display clinical and immunopathologic overlap with sarcoidosis. Blau's syndrome, a genetic disorder of autosomal dominant inheritance, may be confused with infantile sarcoidosis. Vasculitis in sarcoidosis may be underappreciated. Virtually any size vessel may be involved, thus adding to the multiplicity of clinical settings in which sarcoidosis can occur.