Macroscopic qualitative evaluation of solid pancreatic lesion specimens from endoscopic ultrasound-guided fine needle aspiration/biopsies.

OBJECTIVES: To pathologically clarify the macroscopic features of endoscopic ultrasound-guided fine needle aspiration/biopsy (EUS-FNA/B) specimens in representative pancreatic diseases and establish tissue-handling standards based on the macroscopic findings. METHODS: We gathered EUS-FNA/B specimens of cases at our institution with the final diagnoses of pancreatic ductal adenocarcinoma (PDAC, n = 172), neuroendocrine tumor (NET, n = 19), and chronic inflammatory lesion (CIL, n = 24) including autoimmune pancreatitis. We classified the specimens' macroscopic features in five categories (red strings, mixed-red-and-white strings, white cores, gray tissues, gelatinous tissues) and compared the specimens' features on cytological and histological slides. RESULTS: All five macroscopic categories were observed in variable combinations in the PDACs; red strings and white cores predominated in the NETs and CILs. White cores represented neoplastic (PDAC, NET) or lesion (CIL) tissues. Mixed-red-and-white strings were unique to PDACs and contained cancerous cells. Neoplastic cells were numerous in red strings in NETs but not the other groups. Gray and gelatinous tissues represented necrosis and mucin, respectively, and the former were almost exclusively observed in PDACs. Red strings, mixed-red-and-white strings, and white cores were suitable for histological examination, whereas gray and gelatinous tissues were suitable for cytological examination. The white cores, mixed-red-and-white strings, and gelatinous tissues may be composed of non-neoplastic tissues such as contaminated gastrointestinal epithelium. In seven PDACs, although white cores were obtained, a histological diagnosis was not established. CONCLUSIONS: Macroscopic evaluations of EUS-FNA/B can enable the identification of specimen components and a possible diagnosis. They also contribute to the selection of the optimal tissue-handling methods.

Long-term outcomes of drug-induced autoimmune-like hepatitis after pulse steroid therapy.

AIM: Pulse steroid therapy occasionally causes drug-induced autoimmune-like hepatitis (DI-ALH), but the long-term outcome of treated patients is not well known. In this study, we investigated the long-term outcomes of DI-ALH due to pulse steroid therapy. METHODS: We retrospectively reviewed the medical records of 405 patients treated with pulse high-dose methylprednisolone in Kurashiki Central Hospital. The frequency and clinicopathological characteristics of acute liver injury that occurred within 3 months after the therapy were analyzed. The diagnosis of DI-ALH was made according to the revised international autoimmune hepatitis group criteria. RESULTS: Among the 405 patients treated with methylprednisolone, 61 (15.1%) had acute liver injury after the pulse steroid therapy, and DI-ALH was diagnosed in five patients (1.2%). Absence of oral prednisolone tapering after the pulse steroid therapy was a significant risk factor for the subsequent development of DI-ALH (odds ratio 11.9; p = 0.017). One patient was treated with 3 days of intravenous methylprednisolone followed by oral prednisolone. Two patients were treated with glycyrrhizin followed by oral prednisolone due to ineffectiveness of glycyrrhizin. Remission was achieved with glycyrrhizin alone, and spontaneous remission without drug therapy occurred in one patient each. During the median follow-up period of 34 months, no relapse was evident in all the patients without maintenance therapy. CONCLUSIONS: Pulse steroid therapy can cause DI-ALH, especially when subsequent prednisolone is not tapered. Prednisolone is effective for DI-ALH due to pulse steroid therapy, and can be safely withdrawn once remission is achieved.

Salivary gland polymorphous adenocarcinoma: Clinicopathological features and gene alterations in 36 Japanese patients.

BACKGROUND: Polymorphous adenocarcinoma is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of polymorphous adenocarcinoma-associated genes, such as PRKD1/2/3, ARID1A, and DDX3X, in a large cohort of Japanese patients with polymorphous adenocarcinoma. METHODS: We examined the cases of 36 Japanese patients with salivary gland polymorphous adenocarcinoma and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for polymorphous adenocarcinoma-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations. RESULTS: This study revealed the indolent clinical course of polymorphous adenocarcinoma with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (23.3%). Twenty cases (55.6%) of polymorphous adenocarcinoma (but none of the mimics) exhibited alterations in at least one polymorphous adenocarcinoma-associated gene. Rearrangement of polymorphous adenocarcinoma-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (p = 0.0005), the presence of prominent nucleoli (p = 0.0003), and ARID1A split positivity (p = 0.004) were independent risk factors for disease-free survival. CONCLUSION: Japanese patients with polymorphous adenocarcinoma showed clinicopathological features similar to those reported in Western countries. This study disclosed that polymorphous adenocarcinoma-associated genetic alterations were common and specific findings in polymorphous adenocarcinomas. The diagnostic role and possible prognostic significance of polymorphous adenocarcinoma-associated genetic alterations in polymorphous adenocarcinomas were suggested.

Investigation of IgG4-positive cells in idiopathic multicentric Castleman disease and validation of the 2020 exclusion criteria for IgG4-related disease.

Patients with plasma cell type idiopathic multicentric Castleman disease (PC-iMCD) often show elevated serum IgG4 levels and IgG4-positive cell infiltration in tissues due to overproduction of interleukin-6, and may meet the diagnostic criteria for IgG4-related disease (IgG4-RD). Although PC-iMCD has been listed as a major exclusion disease for IgG4-RD, distinguishing between these diseases is challenging due to a lack of highly specific diagnostic biomarkers. In 2020, we proposed exclusion criteria of IgG4-RD mimickers. In this paper, we validated the accuracy of the criteria in excluding one of the mimickers, PC-iMCD, from IgG4-RD. Validation was performed on 57 PC-iMCD patients (39 presenting lymph node lesions and 19 with lung lesions) and 29 IgG4-RD patients (22 presenting lymph node lesions and seven with lung lesions). According to our results, 20.5% of the PC-iMCD patients with lymph node lesions and 42.1% of those with lung lesions met the diagnostic criteria for IgG4-RD. All these patients with PC-iMCD were excluded from a diagnosis of IgG4-RD by the proposed criteria. Additionally, 6.9% of IgG4-RD patients met the exclusion criteria. Thus, if the exclusion criteria are met, diagnosis should be made based on a combination of findings including organ distribution of disease, response to steroid therapy, and other pathological findings.

Immunoglobulin G4 (IgG4)-related autoimmune hepatitis and IgG4-hepatopathy: A histopathological and clinical perspective.

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a chronic inflammatory disease that simultaneously or consecutively involves multiple organs of the body. It is characterized by elevated serum IgG4 levels and massive infiltration of IgG4+ plasma cells in the damaged tissues. IgG4-related autoimmune hepatitis (IgG4-AIH) and IgG4-hepatopathy are relatively new entities that have been proposed as a phenotype of IgG4-RD in the liver. Immunoglobulin G4-AIH is defined as a disorder with serological, histopathological, and clinical features of both IgG4-RD and AIH, simultaneously satisfying the diagnostic criteria of both classical AIH and IgG4-RD. Although there are several case reports and studies of IgG4-AIH among the published works, no consensus regarding the histopathological characteristics of IgG4-AIH has been established, and its clinical implications remain obscure. Immunoglobulin G4-hepatopathy is defined as a comorbidity of IgG4-RD in the liver, and patients not meeting the diagnostic criteria of classical AIH could be diagnosed with IgG4-hepatopathy. Numerous issues regarding these diseases, especially their epidemiology, histopathological and clinical characteristics, and treatment response to corticosteroids, remain unsolved, and need to be determined to establish the disease concepts of IgG4-AIH and IgG4-hepathopathy.

Utility of gastric biopsy in diagnosing IgG4-related gastrointestinal disease.

The utility of gastric biopsy for diagnosing immunoglobulin (Ig)G4-related gastrointestinal disease (IgG4-GID) remains unclear. Bottom-heavy plasmacytosis (BHP) is a distinct feature of IgG4-GID. To clarify the feasibility of using gastric biopsies to diagnose BHP in IgG4-GID, we analyzed the histological features and immunostaining of gastric biopsy specimens from 31 known IgG4-related disease (IgG4-RD) patients and we assessed the presence of BHP in 1696 consecutive routine gastric biopsies. Cases with both >10 IgG4-positive plasma cells per high-power field and an IgG4/IgG-positive ratio >40% were defined as IgG4-high. Ten of the 31 IgG4-RD patients were concluded to have IgG4-GID, in which IgG4-positive plasma cells were notably detected at the deeper part of the mucosa. Six cases displayed BHP whereas the remaining four cases showed transmural infiltration with concomitant Helicobacter pylori-associated gastritis. In addition to BHP, we identified two unique histologic features for IgG4-GID: plasmacytic aggregation in the muscularis mucosae and permeative plasmacytic infiltration between fundic glands in the non-atrophic mucosa. Six of the routine cases (0.35%) displayed BHP, including a case with IgG4-RD. IgG4-GID can be suspected by the presence of gastric biopsy specimens with characteristic histological features. Such cases are recommended to undergo further examinations to determine whether IgG4-RD is present.

Efficacy and limitations of the histological diagnosis of type 1 autoimmune pancreatitis with endoscopic ultrasound-guided fine needle biopsy with large tissue amounts.

OBJECTIVES: We examined the efficacy and limitations of acquiring large specimens by endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for diagnosing type 1 autoimmune pancreatitis (AIP). METHODS: Patients from 12 institutions with non-neoplastic diseases or pancreatic ductal adenocarcinoma (PDAC) with large EUS-FNB specimens were investigated. Slides stained with hematoxylin-eosin, elastic, IgG4, and IgG stains were evaluated. The IgG4- and IgG-positive cell numbers were counted in three foci. The diagnoses were based on the Japan Pancreas Society 2011 (JPS 2011) criteria and the International Consensus Diagnostic Criteria (ICDC). RESULTS: We analyzed 85 non-neoplastic (definite type 1 AIP in 73/85 based on the ICDC) cases and 64 PDAC cases. IgG4-positive cells were numerous (>10 in 85.9%), and the IgG4/IgG ratios were high (>40% in 81.2%). Plasma cell crushing by an artifact caused unsuccessful immunostaining, notably in smaller samples. Tissue lengths were an important factor for the presence of storiform fibrosis and obliterative phlebitis, but storiform fibrosis was equivocal even in large tissues. A definite or possible histological diagnosis was achieved in 45.9% (39/85) and 41.2% (35/85), respectively, and contributed to the definite final diagnosis of type 1 AIP in 33.3% (ICDC) and 55.6% (JPS 2011) in cases with segmental/focal lesions. In the PDAC group, >10 IgG4-positive cells was rare (2/58), but elastic stains revealed fibrous venous occlusions in 10.3% (6/58). CONCLUSIONS: EUS-FNB with large tissue amounts was useful for diagnosing type 1 AIP, notably by facilitating successful IgG4 immunostaining, but definite diagnosis may not be achieved even in cases with large specimens.

Pancreatic neuroendocrine carcinoma G3 may be heterogeneous and could be classified into two distinct groups.

BACKGROUND/OBJECTIVES: Pancreatic neuroendocrine carcinoma (PanNEC)-G3 often presents along with genetic abnormalities such as KRAS, RB1, and TP53 mutations. However, the association between these genetic findings and response to chemotherapy and prognosis has not been clarified. This study aimed to clarify the clinicopathological features of PanNEC-G3. METHODS: We performed a subgroup analysis of the Japanese PanNEN-G3 study (multicenter, retrospective study), which revealed that Rb loss and KRAS mutation were predictors of the response to platinum-based regimen in PanNEN-G3. We re-classified WHO grades of PanNENs using the 2017 WHO classification and then analyzed the clinicopathological features and prognostic factors in 49 patients with PanNEC-G3. RESULTS: The rates of Rb loss and KRAS mutation in PanNEC-G3 were 54.5% and 48.7%, respectively. Patients with Rb loss and/or KRAS mutation showed a higher response rate to first-line platinum-based regimen than those without Rb loss or KRAS mutation (object response rate 70.0% vs 33.3%, odds ratio 9.22; 95% CI 1.26-67.3, P = 0.029), but tended to have shorter overall survival rates than those without Rb loss or KRAS mutation (median 239 vs 473 days, hazard ratio 2.11; 95% CI 0.92-4.86, P = 0.077). CONCLUSIONS: Patients with PanNEC-G3 have varied clinical outcomes for platinum-based regimen. When grouped based on Rb loss and KRAS mutation, there seemed to be two groups with distinct prognoses and responses to the platinum-based regimen. PanNEC-G3 could, therefore, be classified into two distinct groups based on immunohistochemical and genetic findings.

Clinicopathological differential diagnosis of IgG4-related disease: A historical overview and a proposal of the criteria for excluding mimickers of IgG4-related disease.

IgG4-related disease (RD) is a relatively new entity, which was first proposed in 2001. Since then, clinical and pathological characteristics of the disease have been investigated. As IgG4-RD has been studied extensively, the diagnostic criteria for IgG4-RD of each organ and the comprehensive diagnostic criteria for IgG4-RD have also been developed. However, one of the biggest challenges in the field is distinguishing between IgG4-RD and mimickers, which show overlapping features with IgG4-RD. It is now known that some non-IgG4-RDs may meet the diagnostic criteria of IgG4-RD and can be misdiagnosed as IgG4-RD. However, accurate diagnosis is crucial, as the treatments for IgG4-RD and those for other diseases that may be misdiagnosed as IgG4-RD are different. This prompted us to create and propose comprehensive exclusion criteria for IgG4-RD. In this review, we have described the comprehensive exclusion criteria for IgG4-RD, with a historical overview of the disease. These exclusion criteria were recently created by the Research Program for Intractable Disease of the Ministry of Health, Labor, and Welfare of Japan, All Japan IgG4 team, to support correct and accurate diagnosis of IgG4-RD.

Guidance for diagnosing autoimmune pancreatitis with biopsy tissues.

The biopsy-based diagnosis of autoimmune pancreatitis (AIP) is difficult but is becoming imperative for pathologists due to the increased amount of endoscopic ultrasound-guided biopsy tissue. To cope with this challenge, we propose guidance for the biopsy diagnosis of type 1 AIP. This guidance is for pathologists and comprises three main parts. The first part includes basic issues on tissue acquisition, staining, and final diagnosis, and is intended for gastroenterologists as well. The second part is a practical guide for diagnosing type 1 AIP based on the AIP clinical diagnostic criteria 2018. Inconsistent histological findings, tips for evaluating IgG4 immunostaining and key histological features including the ductal lesion and others are explained. Storiform fibrosis and obliterative phlebitis are diagnostic hallmarks but are sometimes equivocal. Storiform fibrosis is defined as spindle-shaped cells, inflammatory cells and fine collagen fibers forming a flowing arrangement. Obliterative phlebitis is defined as fibrous venous obliteration with inflammatory cells. Examples of each are provided. The third part describes the differentiation of AIP from pancreatic ductal adenocarcinoma (PDAC), focusing on histological features of acinar-ductal metaplasia in AIP, which is an important mimicker of PDAC. This guidance will help standardize pathology reports of pancreatic biopsies for diagnosing type 1 AIP.

Surgery for Pancreatic Neuroendocrine Tumor G3 and Carcinoma G3 Should be Considered Separately.

BACKGROUND: The role of surgery in pancreatic neuroendocrine neoplasm grade 3 (pNEN-G3) treatment remains unclear. We aimed to clarify the role of surgery for pNEN-G3, which has recently been reclassified as pancreatic neuroendocrine tumor-G3 (pNET-G3) and pancreatic neuroendocrine carcinoma-G3 (pNEC-G3), with and without metastases, respectively. METHODS: We analyzed a subgroup of patients from the Japanese pancreatic NEC study, a Japanese multicenter case-series study of pNEN-G3. Pathologists subclassified 67 patients as having pNET-G3 or pNEC-G3 based on morphological features. We compared the overall survival (OS) rates among patients who were grouped according to whether they had undergone tumor-targeted surgery for tumors without (SwoM) or with (SwM) metastases, or non-surgical procedures (NS). RESULTS: Data from 21 patients with pNET-G3 (SwoM, n = 6; SwM, n = 5; NS, n = 10) and 46 patients with pNEC-G3 (SwoM, n = 8; SwM, n = 5; NS, n = 33) were analyzed. OS of patients with pNET-G3 was significantly longer after SwoM and SwM than with NS (p = 0.018 and p = 0.022). In contrast, OS did not significantly differ between either SwoM or SwM and NS (p = 0.093 and p = 0.489) among patients with pNEC-G3. CONCLUSION: The role of surgery should be considered separately for pNET-G3 and pNEC-G3. Although SwoM and SwM can be considered for pNET-G3, caution is advised before considering SwM and SwoM for pNEC-G3.

Long-term outcomes of pediatric-onset primary sclerosing cholangitis: A single-center experience in Japan.

AIM: Primary sclerosing cholangitis (PSC) is very rare in Japan. Although a large-scale cohort study of 781 pediatric-onset PSC patients in Europe and North America showed that the 5-year survival with native liver was 88%, the long-term outcomes of pediatric-onset PSC in Japan are unknown. Here, we evaluated the clinical outcomes of pediatric-onset PSC in Japan. METHODS: We carried out a retrospective cohort study with a medical records review of pediatric PSC patients diagnosed between 1986 and 2017 at a single center. The PSC diagnoses were based on cholangiography, liver histology, and biochemical findings. The patients' survival was analyzed using the Kaplan-Meier method. Prognostic factors were determined by univariate and multivariate analyses using the Cox proportional hazards regression model. RESULTS: We identified 39 pediatric-onset PSC patients (22 boys, 17 girls). The median age at diagnosis was 9 years (interquartile range 6.0-13.5 years). The median follow-up period was 5.5 years (interquartile range 3.4-8.7 years). The phenotypes of PSC-autoimmune hepatitis, PSC-inflammatory bowel disease, and small-duct PSC were diagnosed in 13 (33.3%), 36 out of 38 (94.8%), and three (7.7%) patients, respectively. The 5-year liver transplantation-free survival of the whole cohort was 93.5%. Nine patients underwent liver transplantation, and four of these nine cases resulted in death. Both the univariate and multivariate analyses showed that the phenotype of "PSC-autoimmune hepatitis overlap" was an independent poor prognostic factor. CONCLUSIONS: The overall survival of pediatric-onset PSC in Japan was comparable to those in Western countries. The phenotype of PSC-autoimmune hepatitis was identified as a prognostic factor associated with a poorer long-term outcome.

An unusual case of Aß2M amyloid deposition in bladder cancer in a non-dialysis patient.

ß2-microglobulin-related (Aß2M) amyloidosis (dialysis-associated amyloidosis) is a common complication in long-term dialysis patients. An increased concentration of ß2-microgloblin (ß2-m) in the serum appears to be a prerequisite for Aß2M amyloidosis, in turn causing Aß2M amyloid deposition predominantly in the osteoarticular tissue. There are few reports, however, of Aß2M amyloid deposition in non-dialysis patients. We describe an atypical case of a non-dialysis patient with Aß2M amyloid deposition in bladder cancer. A Japanese man in his 80s with no history of dialysis was admitted for transurethral resection of bladder cancer. Histopathological analysis revealed a small amount of amyloid deposition in the small-vessel wall of both the peripheral urothelial carcinoma and necrotic area. Amyloid typing by immunohistochemistry was strongly positive for anti-ß2-m antibody, and ß2-m was most frequently detected in laser microdissection-liquid chromatography tandem mass spectrometry. Although Aß2M amyloidosis was expected, contrary to this, the patient's serum ß2-m was only 4 mg/L, although his urine ß2-m level was increased at 1340 mg/L. The unique findings observed in our patient may contribute to the elucidation of the novel pathogenesis of Aß2M amyloid fibril formation that is distinct from conventional Aß2M amyloidosis.

[Recurrence of malignant lymphoma immediately after treatment for hepatitis C virus using direct-acting antivirals].

A Japanese male in his 70s with chronic hepatitis C was diagnosed with diffuse large B-cell lymphoma and achieved and maintained complete remission following treatment with eight cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisolone). Seven years later, he received the direct-acting antivirals (DAAs) sofosbuvir/ledipasvir for hepatitis C virus (HCV) genotype 1b. Although the patient achieved sustained virological response immediately after the initial treatment period, laboratory data showed elevation of LD and soluble IL-2R. Computer tomography showed diffuse intraabdominal lymph node swelling and splenomegaly. Lymph node biopsy revealed the relapse of lymphoma. The lymphoma cells were resistant to chemotherapy, and the patient died five months later. Several studies reported early recurrence of hepatocellular carcinoma after HCV treatment using DAAs. However, the relationship between DAAs and hepatocellular carcinoma recurrence remains unclear. Nonetheless, possible cancer recurrence should be considered in patients with a history of lymphoma who are prescribed DAAs to treat HCV.

TAFRO syndrome successfully treated with tocilizumab: A case report and systematic review.

Thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly (TAFRO) syndrome is considered as a unique clinicopathologic variant of multicentric Castleman's disease and is recently reported in Japan. This entity represents a severe inflammatory state leading to organ failures such as severe liver dysfunction seen in our case, and can be treated by immunosuppressive agents, steroids, and cyclosporine shown in several case reports. A systematic review and our case suggest the potential utility of tocilizumab as a treatment for TAFRO syndrome.

Abundant immunoglobulin (Ig)G4-positive plasma cells in interstitial pneumonia without extrathoracic lesions of IgG4-related disease: is this finding specific to IgG4-related lung disease?

AIMS: There have been few reports on immunoglobulin-G4 (IgG4)-related interstitial pneumonia (IP), and its clinical features remain unclear. The objective of this study was to assess whether IP with marked IgG4-positive plasma cell infiltration without extrathoracic lesions of IgG4-related disease (RD) should be diagnosed as a subtype of IgG4-RD or a separate entity. METHODS AND RESULTS: All consecutive patients with surgical lung biopsy-proven idiopathic IP with an IgG4/IgG-positive cell ratio of >40% and >50 IgG4+ plasma cells in a high-power field without extrathoracic lesions of IgG4-RD were reviewed retrospectively. Five patients were enrolled into this study. All patients were male with a history of smoking. Four patients met the comprehensive diagnostic criteria for IgG4-RD. The remaining patient lacked data related to the serum IgG4 level. Histologically, a non-specific IP pattern was observed in all patients. The key morphological features of IgG4-RD, such as storiform fibrosis and obliterative phlebitis with lymphoplasmacytic infiltration in a loose background texture, were absent in every patient. In contrast, venule obstruction by densely packed lymphoplasmacytic infiltration was observed in two patients. Marked scarring and remodelling of the lung were also noted, which is not seen typically in IgG4-RD. A favourable response to corticosteroid monotherapy was observed in all patients; however, two patients developed lung cancer during the course of observation. CONCLUSIONS: IP with marked IgG4-positive plasma cell infiltration without extrathoracic lesions of IgG4-RD had different pathological features from those of IgG4-RD, and it is appropriate to regard this as a separate entity.

Serological and morphological prognostic factors in patients with interstitial pneumonia with autoimmune features.

BACKGROUND: To identify the prognostic factors for survival in patients with interstitial pneumonia with autoimmune features (IPAF) who meet the serological domain of the IPAF criteria. METHODS: We retrospectively analysed 99 IPAF patients who met the serological domain and were hospitalised at the Respiratory Medicine Unit of Kurashiki Central Hospital from 1999 to 2015. The high-resolution computed tomography findings were usual interstitial pneumonia (UIP; n = 1), non-specific interstitial pneumonia (NSIP; n = 63), NSIP with organizing pneumonia (OP) overlap (n = 15), and OP (n = 20). One patient who had radiological UIP pattern, and met the serological and clinical domains was excluded. The clinical characteristics, radiological findings, administered therapy, and prognosis of the remaining 98 IPAF patients who met the serological and morphological domains were analysed. RESULTS: The median age of the 98 IPAF patients was 68 years, and 41 (41.8%) of them were men. Twelve (12.2%) of the 98 IPAF patients developed other characteristics and were diagnosed with connective tissue disease (CTD) later during the median follow-up of 4.5 years. Univariate Cox analysis revealed systemic sclerosis (SSc)-specific and SSc-associated antibodies (ANA nucleolar pattern, ANA centromere pattern, anti-ribonucleoprotein and anti-Scl-70) positive IPAF, radiological NSIP pattern, bronchoalveolar lavage fluid lymphocytes >15%, and age as significant prognostic factors for survival. Multivariate Cox analysis revealed radiological NSIP pattern (hazard ratio [HR], 4.48; 95% confidence interval [CI], 1.28-15.77, p = 0.02) and age (HR, 1.07; 95% CI, 1.02-1.11, p = 0.01) were significantly associated with worse survival. CONCLUSIONS: We confirmed that radiological NSIP pattern and age are poor prognostic factors for the survival of IPAF patients. This study suggested that the autoantibodies that are highly specific for certain connective tissue diseases might be less important for the prognosis of IPAF compared with the radiological-pathological patterns. The relatively high proportion of IPAF patients who developed CTD later suggests the importance of careful observation for evolution to CTD in IPAF.

Pathogenicity of IgG in patients with IgG4-related disease.

OBJECTIVE: IgG4-related disease (IgG4-RD) is a systemic disease characterised by elevated serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in the affected tissues. The pathogenic role of IgGs, including IgG4, in patients with IgG4-RD, however, is unknown. DESIGN: We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal male Balb/c mice. Binding of patient IgGs to pancreatic tissue was also analysed in an ex vivo mouse organ culture model and in tissue samples from patients with autoimmune pancreatitis (AIP). RESULTS: Subcutaneous injection of patient IgG, but not control IgG, resulted in pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patient IgG1 or IgG4, with more destructive changes induced by IgG1 than by IgG4. The potent pathogenic activity of patient IgG1 was significantly inhibited by simultaneous injection of patient IgG4. Binding of patient IgG, especially IgG1 and IgG4, to pancreatic tissue was confirmed in both the mouse model and AIP tissue samples. CONCLUSIONS: IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding affected tissues in neonatal mice.

Diagnosis of autoimmune pancreatitis by EUS-guided FNA using a 22-gauge needle: a prospective multicenter study.

BACKGROUND AND AIMS: Histopathologic examination is critical for diagnosing autoimmune pancreatitis (AIP). However, specimens obtained using EUS-guided FNA (EUS-FNA) are not recommended for histopathologic diagnosis because of inadequate sample size volume. We evaluated EUS-FNA efficacy for AIP diagnosis using a 22G needle. METHODS: Seventy-eight patients exhibiting the imaging characteristics indicative of AIP in the pancreatic parenchyma and pancreatic duct underwent EUS-FNA with a 22G needle at 12 institutions between February 2013 and March 2014. Samples were evaluated for tissue sampling conditions, CD38- and IgG4-positive plasma cell counts, storiform fibrosis (SF), and obliterative phlebitis (OP). RESULTS: Tissue specimens containing >10, 5 to 10, and 1 to 4 high-power fields (HPFs) were obtained from 29 (37.2%), 18 (23.1%), and 15 (19.2%) of 78 patients, respectively. The mean ± standard deviation (SD) CD38- and IgG4-positive plasma cell counts were 23.2 ± 18.8/HPF and 5.1 ± 6.7/HPF, respectively. SF was detected in 49 of 78 patients (62.8%) and OP in 38 of 78 patients (48.7%). According to the International Consensus Diagnostic Criteria (ICDC), histopathologic levels corresponded to level 1 in 32, level 2 in 13, and unclassifiable in 17 patients. Hence, 45 of 78 patients (57.7%) could be diagnosed with lymphoplasmacytic sclerosing pancreatitis according to ICDC. CONCLUSIONS: Pancreatic tissues with at least 1 HPF were obtained by EUS-FNA from approximately 80% of patients, and nearly 60% of patients were diagnosed with ICDC level 2 or higher. Our findings indicate that EUS-FNA with a 22G needle may be useful for the histopathologic diagnosis of AIP. (Clinical trial registration number: UMIN000010097.).