Received date: February 16, 2016; Accepted date: April 14, 2016; Published date: April 18, 2016
Citation: Suzuki T, Fujita A, Takamori M, Murata K, Wada A, et al. (2016) Implication of Immunohistochemistry for Propionibacterium acnes in Differential Diagnosis of Necrotizing Granuloma. J Pulm Respir Med 6:335. doi:10.4172/2161-105X.1000335
Copyright: © 2016 Suzuki T, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Propionibacterium acnes (P. acnes) have been reported to have an etiologic link with sarcoidosis. A 45-year-old Japanese woman complaining of cough for 1 month presented to our hospital. Chest computed tomography showed an irregular nodular shadow in the right upper pulmonary lobe, a finding suggestive of either pulmonary sarcoidosis or tuberculosis. Biopsy specimens from the pulmonary shadow showed necrotizing granulomas, and there were no other findings from the initial laboratory examinations that could provide a definitive diagnosis. However, immunohistochemical staining using a P. acnes-specific monoclonal antibody revealed small round bodies within the granulomas. Based on these results, we diagnosed the patient clinically with sarcoidosis, and orally inhaled ciclesonide was administered. At a 7-month follow up, the patient had improved clinically and radiologically. The outcome of this case indicates that immunohistochemical evaluation using a P. acnes antibody may be useful for diagnosing necrotizing granuloma.
Necrotizing granuloma; Propionibacterium acnes; Sarcoidosis; Tuberculosis
ACE: Angiotensin-Converting Enzyme; ANCA: Antineutrophil Cytoplasmic Antibodies; BALF: Bronchoalveolar Lavage Fluid; CT: Computed Tomography; NSG: Necrotizing Sarcoid Granuloma; PAB Antibody: Propionibacterium acnes- Specific Monoclonal Antibody that Reacts with Cell-Membrane- Bound Lipoteichoic Acid; P. acnes: Propionibacterium acnes; TBLB: Transbronchial Lung Biopsy
Important causes of granulomatous lung disease in Japan include sarcoidosis and tuberculosis, which are difficult to differentiate. The two diseases are not so rare in Japan, where 7.5 to 9.3 individuals per 100,000 people are estimated to have sarcoidosis, and 16.1 per 100,000 people are estimated to have tuberculosis . Distinguishing pulmonary sarcoidosis from tuberculosis can sometimes be very difficult, since they have pathological similarities. The finding of necrotizing granuloma cannot exclude pulmonary sarcoidosis, because it was reported that 6% of sarcoidosis patients had necrotizing granulomas . There are recent reports suggesting that Propionibacterium acnes (P. acnes) might have an etiologic association with sarcoidosis [3-7]. The investigators used a P. acnes-specific monoclonal antibody (PAB antibody) that detected small round bodies in sarcoid granulomas with high frequency and specificity [3,4]. The PAB antibody did not react with tuberculous granulomas.
We herein present a patient with pulmonary sarcoidosis with necrotizing granulomas, whose findings on initial laboratory testing were not typical of sarcoidosis, but for whom immunohistochemical staining using an antibody to P. acnes was useful to perform correct diagnosis.
A 45-year-old Japanese woman who was a former smoker presented to our hospital with a 1 month history of cough. On her first visit to our clinic, she was afebrile, and chest auscultation was negative for wheezing and rales. Chest computed tomography (CT) revealed an irregular nodular shadow in the right upper pulmonary lobe, which suggested either pulmonary sarcoidosis or tuberculosis (Figure 1A). Gallium-67 scintigraphy was negative for gallium uptake. The laboratory findings are presented in Table 1. In brief, no obvious abnormalities were observed on initial laboratory testing, including serum levels of calcium and angiotensin-converting enzyme (ACE), or the presence of antineutrophil cytoplasmic antibody. An interferon-gamma release assay (QuantiFERON®-TB Gold) was also negative. A transbronchial lung biopsy (TBLB) of a nodule showed eosinophilic necrotizing granulomas that stained negative for acid-fast bacilli (Figure 1B). Analysis of bronchoalveolar lavage fluid (BALF) showed a total cell count of 2.78 × 105 cells/mL, with 11.4% lymphocytes and a CD4/CD8 ratio of 1.98. The cultures of TBLB and BALF were negative for bacterial growth, including acid-fast bacilli, and fungal growth. These results were inconclusive for differentiating between pulmonary sarcoidosis and tuberculosis.
Table 1: Laboratory data on admission (ACE: Angiotensin-Converting Enzyme; ALB: Albumin; ALP: Alkaline Phosphatase; ALT: Alanine Aminotransferase; AST: Aspartate Aminotransferase; BUN: Blood Urea Nitrogen; Ca: Calcium; Cl: Chlorine; Cre: Creatinine; CRP: C-Reactive Protein; Hb: Hemoglobin; Hct: Hematocrit; K: Kalium; LDH: Lactate Dehydrogenase; MPO-ANCA: Myeloperoxidase Antineutrophil Cytoplasmic Antibody; Na: Natrium; Plt: Platelet; PR3-ANCA: Proteinase-3 Antineutrophil Cytoplasmic Antibody; RBC: Red Blood Cell; TP: Total Protein; WBC: White Blood Cell).
Figure 1: A: Chest computed tomography on the patient’s first visit to our clinic revealed an irregular nodular shadow in the right upper pulmonary lobe. B: A transbronchial lung biopsy (TBLB) specimen from the nodule showed necrotizing granulomas (hematoxylin-eosin stain; original magnification, X400). Necrosis is indicated by the black arrow, and the granuloma with Langhans giant cells is indicated by the blue arrow. C: Propionibacterium acnes organisms within a sarcoid granuloma of the transbronchial lung biopsy (TBLB) specimen. Immunostaining with Propionibacterium acnes-specific monoclonal antibody (PAB antibody) is shown (original magnification, X1000). Many small round bodies are seen within the granulomas (black arrows). D: Chest radiographs before and after treatment with inhaled ciclesonide. The abnormal shadow in the right upper lung field (blue arrow) disappeared after the treatment.
However, immunostaining of a biopsy specimen using a P. acnes-specific monoclonal antibody (PAB antibody) revealed many small round bodies in the granulomas (Figure 1C). Based on this result, we diagnosed the patient clinically with sarcoidosis. The patient was prescribed ciclesonide inhalation (400 μg twice daily) and followed closely. Seven months after she started treatment, her cough resolved, and her chest radiograph showed marked improvement (Figure 1D), which was not compatible with the time course of active tuberculosis.
There are a variety of pulmonary granulomatous diseases, including sarcoidosis, tuberculosis, fungal disease, granulomatosis with polyangiitis, collagen disease, autoimmune disease, and hypersensitivity pneumonitis. Among these conditions, differentiating between pulmonary sarcoidosis and tuberculosis is very difficult, since they have clinical and radiological similarities. The pathological hallmark of sarcoidosis is noncaseating granuloma, but some patients have been reported with necrotizing granuloma .
The etiology of sarcoidosis is still unknown. However, it has been reported to be a result of an abnormal immune response to certain antigenic stimuli. Mycobacterium tuberculosis and P. acnes are the most commonly implicated causative organisms . To date, P. acnes is the only microorganism that has been isolated from bacterial cultures of specimens from sarcoid lesions [8,9]. Negi et al. recently reported that P. acnes were detected with high frequency and specificity in sarcoid granulomas by a P. acnes-specific monoclonal antibody (PAB antibody) that reacted with cell-membrane-bound lipoteichoic acid . Sarcoidosis may arise from a Th1 immune response to P. acnes in association with a hereditary or acquired abnormality of the immune system .
Sarcoidosis sometimes represents a diagnostic challenge. The work up of our patient revealed the following atypical findings: 1) necrotizing pulmonary granuloma, 2) normal ACE level, 3) negative gallium uptake, and 4) relatively low proportion of lymphocytes and CD4/ CD8 ratio in BALF. There were also no extrapulmonary manifestations of sarcoidosis without mediastinal lymphadenopathy. Although the interferon-gamma release assay was negative, a negative result by itself could not rule out active tuberculosis. The interferon-gamma release assay is not the gold standard for the diagnosis of tuberculosis, and a positive result only supports the diagnosis. Moreover, the CT findings were compatible with tuberculosis, showing endobronchial spread along adjacent airways and relatively well defined nodules with a tree-in- bud pattern. In such cases, an antibody to P. acnes such as the PAB antibody can be useful for supporting the diagnosis of sarcoidosis. Investigators using the PAB antibody found that it did not react with nonsarcoid granulomas in any of 45 tuberculosis samples or 34 samples from sarcoid reactions . Our patient’s cough resolved and her chest radiograph showed improvement after treatment using inhaled ciclesonide for 7 months. Although we were unable to determine if the inhaled ciclesonide led to her improvement, the course of her illness was not compatible with active tuberculosis.
The present report also needs to keep necrotizing sarcoid granulomatosis (NSG) on the list of differential diagnoses to be considered for pulmonary sarcoidosis. NSG is an extremely rare granulomatosis, only about 200 cases were reported in English literature in pubmed . Its pathogenesis still remains unclear. Diagnosis of NSG mainly relies on pathological findings. Non-caseating epithelial cell granulomas of NSG may invade the vessel wall and lumen to form granulomatous vasculitis and lesions of coagulation necrosis; lymphocytes, multinucleated giant cells and other inflammatory cells can infiltrate pulmonary blood vessel walls and cause severe stenosis or occlusion of the vessel lumen with perivascular granuloma formation, all of which were not evident in this case . However, some argued that NSG might be a subtype of sarcoidosis [11,12]. Indeed, there was a report of NSG with P. acnes DNA found in the granulomas of lung specimens .
In summary, we reported a case of pulmonary sarcoidosis that was difficult to differentiate from tuberculosis and were successfully diagnosed by P. acnes-specific immunostaining. The presence of necrosis in a granuloma does not exclude the diagnosis of sarcoidosis. Evaluation by P. acnes-specific immunostaining may be useful for differentiating between granulomatous diseases.
We are grateful to Tamiko Takemura (Department of Pathology, Japanese Red Cross Medical Center, Japan) for her contributions to pathological assessment.
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