Rheumatoid-nodule-like cutaneous granuloma associated with recombinase activating gene 1-deficient severe combined immunodeficiency: A rare case.

Cutaneous granulomas without detectable infectious etiology rarely occur in children and adults with primary immunodeficiency disorders. These cutaneous granulomas are primarily seen in combined variable immunodeficiency, ataxia-telangiectasia, and severe combined immunodeficiency (SCID) and can emulate the reaction patterns seen in sarcoidosis and granuloma annulare. To date, the literature has described only six cases of non-infectious cutaneous granulomas in SCID. We report an unusual case of cutaneous granuloma, mimicking a sarcoma, in a 40-year old male with recombinase activating gene 1-deficient SCID, who presented with a slow-growing globus mass over the lateral aspect of the right elbow. There was heterogeneous enhancement on MRI, which was concerning for neoplasm but no malignancy was found on frozen or permanent sections. GMS, PAS with diastase, and AFB stains, as well as microbiology cultures, were negative. An AE1/AE3 stain was negative and a CD163 stain highlighted histiocytes. No infectious etiology was identified and histopathology revealed palisaded granulomatous dermatitis, most closely resembling a rheumatoid nodule. Although cutaneous manifestations have been reported in nearly half of primary immunodeficiency disorder cases, non-infectious cutaneous granulomas are exceedingly rare in SCID. To our knowledge, this is the first case report of cutaneous palisaded granulomatous dermatitis mimicking a rheumatoid nodule in a major joint.

MMP expression in rheumatoid inflammation: the rs11568818 polymorphism is associated with MMP-7 expression at an extra-articular site.

Matrix metalloproteinases (MMPs) contribute to the joint damage in rheumatoid arthritis (RA). Less is known of the involvement of MMPs at extra-articular sites of rheumatoid inflammation. We assessed the relative contribution from MMP-1, MMP-3, MMP-7 and MMP-12 to joint and extra-articular tissue destruction and inflammation by comparing gene expression in joint synovia and subcutaneous rheumatoid nodules from RA patients. Expression of MMP-1 and MMP-3 predominated in synovia, whereas MMP-12 expression was significantly higher in rheumatoid nodules. Markedly higher MMP-7 expression distinguished a subgroup of nodules that featured infiltrating monocyte/macrophage-producing MMP-7 protein. The high MMP-7 expression in nodules was associated with the single-nucleotide polymorphism (SNP) rs11568818 (-181A>G, MMP-7 promoter) and more active inflammation within the nodule lesions. Patients with such nodules had significantly earlier age of RA onset. Our findings indicate that the expression of MMP-1 and MMP-3 occurs relatively independent of the tissue microenvironment with substantial expression also at extra-articular sites. MMP-12 expression reflects the involvement of monocyte/macrophages in rheumatoid inflammation. Evidence for the association between the rs11568818 SNP and increased MMP-7 expression is restricted to nodules, which indicates that consequences of the MMP-7 polymorphism are likely to manifest within aspects of immune/inflammatory activity that are monocyte/macrophage-mediated.

INI1 and GLUT-1 expression in epithelioid sarcoma and its cutaneous neoplastic and nonneoplastic mimics.

The morphological features of epithelioid sarcoma may closely mimic those of epithelial neoplasms, such as squamous cell carcinoma, mesenchymal tumors, such as benign fibrous histiocytoma, and nonneoplastic lesions, such as granuloma annulare. Immunohistochemistry, particularly for epithelial markers and CD34, thus plays a valuable role in the differential diagnosis of epithelioid sarcoma. However, some epithelioid sarcomas may show very focal or even absent expression of such markers and may be difficult to distinguish from various morphological mimics. There is therefore continued interest in the development of new immunohistochemical markers of epithelioid sarcoma. Recently, loss of expression of INI1, a tumor suppressor gene/protein, and expression of GLUT-1, a glucose transporter protein, have been described in epithelioid sarcoma. We examined the utility of immunohistochemistry for INI1 and GLUT-1 in the diagnosis of epithelioid sarcoma and various cutaneous mimics. Twenty-four cases of epithelioid sarcoma, 13 cases of granuloma annulare, 10 cases of rheumatoid nodule, 19 cases of cutaneous squamous cell carcinoma, 7 cases of atypical fibroxanthoma, 9 cases of benign fibrous histiocytoma (dermatofibroma), and 3 cases of nodular fasciitis were immunostained for GLUT-1 and INI1 using commercially available antibodies, heat-induced epitope retrieval, and the Dako Envision detection system. Total or near-total loss of normal constitutive expression of INI1 protein was noted in more than 85% of epithelioid sarcomas, with 19 of 24 cases (79%) showing complete loss of INI1 expression. In contrast, all other cases studied showed uniformly retained expression of INI1. GLUT-1 was positive in 40%-50% of epithelioid sarcomas, all cases of granuloma annulare and rheumatoid nodules, 67% of benign fibrous histiocytomas, and in all squamous cell carcinomas. In contrast, atypical fibroxanthomas and cases of nodular fasciitis were consistently GLUT-1 negative. We conclude that immunohistochemistry for INI1 expression should be included as part of the routine immunohistochemical panel for the diagnosis of epithelioid sarcoma, along with established markers such as wide-spectrum cytokeratins, cytokeratin 5/6, p63, and CD34. In this clinical context, loss of INI1 expression seems to be an entirely specific marker of epithelioid sarcoma and this finding may be of great value in distinguishing CD34-negative epithelioid sarcoma from squamous cell carcinoma and in the distinction of rare cytokeratin-negative epithelioid sarcomas from necrobiotic processes, nodular fasciitis, and benign fibrous histiocytomas. In contrast, there does not seem to be a role for GLUT-1 immunohistochemistry in this differential diagnosis.

Colocalization of C4d deposits/CD68+ macrophages in rheumatoid nodule and granuloma annulare: immunohistochemical evidence of a complement-mediated mechanism in fibrinoid necrosis.

Rheumatoid nodule (RN) represents a palisading granuloma with central fibrinoid necrosis, which is not only a classical manifestation of rheumatoid arthritis (RA) and part of the American College of Rheumatology (ACR)-criteria, but also is its diagnostic hallmark. The pathogenesis of RN is still not fully understood. At present, only data on serum analyses indicating a complement-mediated pathogenesis in the development of RA are available. Equivalent examinations for RN have not yet been performed. Granuloma annulare (GA) represents another type of palisading granuloma. A special subtype of GA, subcutaneous GA (SGA), is an important differential diagnosis to RN. Therefore, our aim was to examine RN and SGA regarding the complement deposition (C4d) by immunohistochemical means. All RN and GA were stained by hematoxylin/eosin and different special stains. In addition, all specimens were stained immunohistochemically with antibodies against CD68. Five GA and five RN were analyzed immunohistochemically with antibodies against C4d and CD68, and evaluated using single- and doublestaining immunohistochemistry. All RN and GA displayed depositions of C4d within their central necroses and between the surrounding palisading macrophages. Most importantly, C4d/CD68 double staining was visible in the palisading macrophages next to the necroses, while macrophages in the periphery were negative for C4d but positive for CD68. The main difference between RN and GA was a quantitative phenomenon with less positively reacting macrophages in a more incomplete palisade in GA. The positive reactions of all central necroses to C4d and colocalization of CD68 and C4d suggest that a complement-mediated mechanism may be operative in the formation of fibrinoid necrosis. This mechanism may be involved in any form of "fibrinoid necrosis", since no different patterns of C4d/CD68 expression could be observed in GA. This may explain why RG/GA are not distinguishable morphologically.

Polymorphisms of genes for programmed cell death 1 ligands in patients with rheumatoid arthritis.

To investigate the role of ligands for programmed cell death 1 (PD-L) in the pathogenesis of rheumatoid arthritis (RA), 129 patients with RA and 125 unrelated healthy controls were enrolled in this study. The PD-L1 and PD-L2 polymorphisms were determined by the method of polymerase chain reaction (PCR)/direct sequencing or PCR/reaction fragment length polymorphisms. The genotype distributions of PD-L1 6777 C/G were not significantly different between the patients with RA and healthy controls. There was also no significant difference in the allele frequencies of PD-L1 6777 C/G polymorphisms between the patients with RA and controls. Similar findings could also be found in the phenotypes and alleles frequencies of PD-L2 47103 C/T and 47139 T/C polymorphisms between the patients with RA and controls. The patients with PD-L1 6777 G had higher prevalence of rheumatoid nodule in comparison with those without PD-L1 6777 G (p = 0.005, OR = 4.0, 95% CI = 1.5-10.9). In contrast, the PD-L2 47103 C/T and 47139 T/C polymorphisms were not related to the occurrence of rheumatoid nodule. This study demonstrated that the PD-L1 and PD-L2 polymorphisms were not associated with susceptibility to RA in Taiwan. PD-L1 6777 G was associated with the prevalence of rheumatoid nodule.

Citrullination in extra-articular manifestations of rheumatoid arthritis.

BACKGROUND: Anti-citrullinated protein antibodies have been detected with high specificity in serum of patients with rheumatoid arthritis (RA), and citrullination of proteins may play a key role in the pathogenesis of RA. We therefore investigated the presence of citrullination in two extra-articular manifestations of RA, interstitial pneumonia (IP) and rheumatoid nodules. METHODS: Open-lung biopsy specimens from patients with RA-associated IP (n = 18), idiopathic IP (n = 20) and controls (n = 10), as well as specimens of rheumatoid nodules from 26 patients, were examined. All sections were incubated with an anti-modified citrulline antibody. Masked scoring of stained sections and analysis of results by stratification according to demographic and clinical characteristics was performed. RESULTS: Presence of citrulline could be detected in eight lung specimens of patients with RA-associated IP (44%) and nine patients with idiopathic IP (46%). Conversely, lung tissue from control patients showed weak extracellular citrullination in only two cases (20%). Citrullination did not show any significant associations with demographic or clinical characteristics such as age, gender, smoking habits, disease severity, histological subtype, degree of inflammation or steroid use. Rheumatoid nodules were citrulline positive in a majority of cases (70%). CONCLUSION: Citrullination is present in extra-articular manifestations of RA such as IP and nodules. In contrast to the high specificity of anti-citrulline antibodies in RA, citrullination is not only restricted to RA but can also be observed in idiopathic IP. Whether citrullination significantly contributes to the initiation or perpetuation of autoimmunity or merely reflects ongoing inflammation remains to be clarified.

Rheumatoid nodulosis during methotrexate therapy in a patient with rheumatoid arthritis.

We report a 62-year-old man with rheumatoid arthritis (RA) who developed nodulosis after methotrexate (MTX) treatment. The epithelioid cells of nodules were positive for matrix metalloproteinases (MMP)-2, MMP-3, MMP-9, and Ki67. The synovial tissues obtained from the same patient were negative for MMP-3, MMP-9, and Ki67. This study demonstrated that MTX-induced nodules are different from synovial tissues in terms of MMP expression, suggesting the presence of different pathologic mechanisms and differential MTX susceptibility.

Expression of the histiocytic marker PG-M1 in granuloma annulare and rheumatoid nodules of the skin.

BACKGROUND: The expression of PG-M1, the most specific histiocytic marker, has not yet been studied in granuloma annulare (GA) and other palisaded granulomas of the skin. We evaluated the reactivity of PG-M1 with a series of GA and rheumatoid nodules (RN) to establish the sensitivity and potential usefulness of this marker in the diagnosis and characterization of these entities. METHODS: Histological sections from 30 GA and 15 RN were immunostained with PG-M1. For comparison, additional sections were stained with KP-1 and lysozyme. The stains were recorded as negative, weakly positive (1+) and strongly positive (2+). RESULTS: PG-M1 stained all cases of GA (100%). KP-1 and lysozyme stained 26 (86%) and 18 (60%) GA cases, respectively. PG-M1 exhibited a significantly stronger staining intensity (1.8 +/- 0.07) when compared with KP-1 (1.4 +/- 0.13) (p = 0.018) and with lysozyme (0.9 +/- 0.15) (p < 0.0001). All RN were stained by PG-M1 (100%). KP-1 and lysozyme stained 14 (93%) and six (40%) RN cases, respectively. PG-M1 staining intensity (1.6 +/- 0.13) was slightly higher than that of KP-1 (1.4 +/- 0.18) (p = 0.27) and significantly higher than that of lysozyme (0.4 +/- 0.13) (p < 0.0001). CONCLUSIONS: PG-M1 is consistently and strongly expressed by the histiocytic population of GA and RN, being more sensitive and reliable than other histiocytic markers. We recommend its use in difficult cases in which the histiocytic nature of the lesion needs to be confirmed.

Complement mediated vascular endothelial injury in rheumatoid nodules: a histopathological and immunohistochemical study.

OBJECTIVE: To evaluate morphologically and immunohistochemically the role of IgM rheumatoid factor (RF) immune complexes and complement activation in rheumatoid nodule vascular injury, a typical extraarticular manifestation of rheumatoid arthritis. METHODS: Histological features such as cellular infiltration, endothelial alteration, fibrinoid degeneration, and basement membrane alterations were observed in the small vessels in rheumatoid nodules. An immunohistochemical study was also carried out. RESULTS: Distinct colocalization of IgM RF and terminal complement complexes (TCC: C5b-9) was observed on the luminal surface in some of the damaged endothelial cells. Immuno-electron microscopy revealed endothelial vesiculation, typical of the in vitro protective mechanism against complement attack, with deposition of not only TCC but also IgM RF. Most TCC positive endothelial cells simultaneously expressed the major complement regulatory factor, CD59. CONCLUSION: These data suggest that, in rheumatoid nodules, vascular injury mediated by complement activation involves the assembly of IgM RF on the endothelial cell surface.

Broadening of the T cell receptor spectrum among rheumatoid arthritis synovial cell-lines in relation to disease duration.

OBJECTIVE: The aim of the study was to evaluate the T cell receptor (TCR) family usage in T cell-lines from subcutaneous nodules and synovium from patients with rheumatoid arthritis (RA), with specific reference to the duration of symptoms. In vitro adherence characteristics of nodular T cells was studied as well. METHODS: Monoclonal antibodies were used to determine the distribution of TCR families in T cell-lines from synovium of patients with early and long-standing RA, from rheumatoid nodules and control tissues. An in vitro binding assay with T cell-lines from 2 rheumatoid nodules was performed. RESULTS: In early RA synovium, a restricted TCR family usage was observed in 5 out of 8 patients, contrary to long-standing disease, peripheral blood, ileum and colon. In RA nodules, a similar degree of restriction was noted. Moreover, the same TCR family was overexpressed by T cell-lines from different nodules derived from the same patient. T cell-lines from rheumatoid nodules demonstrated a preferential in vitro adherence to rheumatoid synovium and rheumatoid nodules, while no binding was observed on skin or tonsil. CONCLUSION: The TCR spectrum among RA synovial cell-lines broadens in relation to the disease duration. The overexpression of the same TCR family in different rheumatoid nodules from the same patients, and the in vitro adherence of T cell-lines from rheumatoid nodules may be indicative for recirculation between the different disease manifestations in RA.

Detection of sarcolectin-specific receptors like the cytokine macrophage migration inhibitory factor in rheumatoid nodules.

The objective of this study was the evaluation of the relation between the N-acetyl-neuraminic acid-binding endogenous lectin sarcolectin and the cytokine macrophage migration inhibitory factor (MIF) during development of rheumatoid nodules (RN) in seropositive rheumatoid arthritis (RA). Sarcolectin was purified and biotinylated. The binding patterns of this probe were analyzed in RN from patients with RA (n = 23) and compared with the distribution of antibodies with specificity for MIF, fibrin, fibronectin. In early RN, all areas of the inflammatory tissue displayed presence of receptors for sarcolectin. Macrophages were especially positive. In mature rheumatoid nodules binding of sarcolectin was restricted to the periphery of necrotic areas, to endothelial cells and perivascular connective tissue of marginal zones. Distribution patterns of MIF were similar but not identical. The histological staining characteristics demonstrate sarcolectin-binding receptors in RN that are altered upon disease progression. The finding suggests that specific interactions between this endogenous lectin and MIF may be involved in the course of RA.

Pathogenic mechanisms in the rheumatoid nodule: comparison of proinflammatory cytokine production and cell adhesion molecule expression in rheumatoid nodules and synovial membranes from the same patient.

OBJECTIVE: To investigate the production of proinflammatory cytokines and expression of cell adhesion molecules in the rheumatoid nodule. METHODS: Cytokine content (tumor necrosis factor alpha [TNFalpha], interleukin-1beta [IL-1beta], and IL-1 receptor antagonist [IL-1Ra]), at the messenger RNA (mRNA) and protein levels, and cell adhesion molecule expression were studied in 16 rheumatoid nodules and 6 synovial membranes. RESULTS: Macrophages in the rheumatoid nodules contained TNFalpha, IL-1beta, and IL-1Ra mRNA and protein, particularly in perivascular cells of the stroma and in the palisading layer. All cell adhesion molecules studied were expressed in both the rheumatoid nodules and synovial membranes, with increased expression of E-selectin in the rheumatoid nodule compared with the synovial membrane, and with the absence of vascular cell adhesion molecule 1 expression on cells of the palisading layer in the rheumatoid nodule. CONCLUSION: The presence of similar proinflammatory cytokines and cell adhesion molecules in the rheumatoid nodule and synovial membrane suggests that similar pathogenic processes result in the chronic inflammation and tissue destruction in these lesions.

Palisading cells of rheumatoid nodules: comparison with synovial intimal cells.

OBJECTIVES: The palisading cells of rheumatoid nodules share certain features with synovial intimal cells. The similarities between the two cell populations have been reassessed using new cytochemical markers. METHODS: Cell populations in cryostat sections of non-inflamed, rheumatoid and osteoarthritic synovial tissues, and rheumatoid nodules were assessed for the presence of CD68, prolyl hydroxylase, vascular cell adhesion molecule 1 (VCAM-1), and the alpha 4 and beta 1 integrin chains, and the activity of uridine diphosphoglucose dehydrogenase (UDPGD) and nonspecific esterase. RESULTS: Synovial intimal cells formed a dual population of macrophages (nonspecific esterase positive, strongly positive for CD68) and fibroblastic cells (prolyl hydroxylase positive). The latter showed prominent VCAM-1 expression and high UDPGD activity as previously reported and also prominent beta 1 integrin chain expression. Palisading cells similarly proved to be a dual population of macrophages and fibroblastic cells. In contrast with synovial intima, however, the fibroblastic cells lacked UDPGD activity and expression of VCAM-1 and showed no preferential expression of the beta 1 integrin chain. The exception to this rule was where nodules contained central clefts, which were lined with cells showing all the features associated with synovial intimal cells. CONCLUSION: Palisading cells are a mixture of macrophages and fibroblasts, but the latter show no evidence of synoviocyte differentiation. Cells with features of synoviocytes may occur lining clefts within areas of necrobiosis.

Presence of human 65 kD heat shock protein (hsp) in inflamed joints and subcutaneous nodules of RA patients.

Monoclonal antibodies to the human homologue of the bacterial 65 kD heat shock protein (hsp) were used to investigate the tissue distribution of endogenous hsp 65 in normal versus rheumatoid synovial tissue, in subcutaneous nodules of patients with rheumatoid arthritis (RA) and in several instances of non-rheumatoid inflammation. A strong reactivity of the anti-hsp antibody was found in the cartilage-pannus junction in rheumatoid joints and in rheumatoid nodules, but not in normal joints or in normal or inflamed kidney or liver (irreversible graft rejection, chronic glomerulonephritis or primary biliary cirrhosis). The findings provide a new hypothetical explanation for a role of T cells reactive with the 65 kD hsp in the generation of both articular and extra-articular lesions in chronic rheumatoid arthritis.

Terminal N-acetylglucosamine in chronic synovitis.

The distribution of terminal GlcNAc residues in normal and diseased synovial tissue has been studied using a mouse monoclonal antibody (mAb) which binds to terminal N-acetylglucosamine (GlcNAc). Normal human connective tissue, including synovium, showed no staining for terminal GlcNAc. Normal epithelial tissues, including tonsillar epithelium, skin, small intestinal epithelium and salivary epithelium showed cellular staining. Synovium from patients with definite rheumatoid arthritis showed dense granular staining of macrophages. In addition, synovium from 9 of 12 patients with definite rheumatoid arthritis showed reticular extracellular staining indicating deposition of material bearing terminal GlcNAc in the connective tissue stroma. The extracellular staining was not seen in synovium from patients with osteoarthritis. Extracellular material bearing terminal GlcNAc may act as an inflammatory stimulus in rheumatoid arthritis, either by acting as antigen or by interaction with receptors on macrophage membranes which also recognize GlcNAc on bacterial material, thus triggering biochemical pathways normally occurring in response to the presence of micro-organisms.

Immunological and immunohistochemical analysis of rheumatoid nodules.

An attempt was made to examine the pathophysiology of the rheumatoid nodule. Significant amounts of interleukin 1-like activity and prostaglandin E2 were detected in the supernatants from in vitro organ cultures of rheumatoid nodule tissue. When fresh (but not old) rheumatoid nodules were minced and cultured in vitro prominent outgrowths of cells were observed. These cells expressed both HLA-DR and CD14 antigens but lacked conventional differentiation antigens for T cells and B cells, suggesting that they are of monocyte-macrophage origin. These data suggest that interleukin 1 and prostaglandin E2 may be deeply involved in the formation of rheumatoid nodules.