Kidney Involvement in Patients with Type 1 Autoimmune Pancreatitis.

INTRODUCTION: Autoimmune pancreatitis (AIP) type 1 is a special form of chronic pancreatitis with a strong lymphocytic infiltration as the pathological hallmark and other organ involvement (OOI). IgG4-related kidney disease (IgG4-RKD) was first reported as an extrapancreatic manifestation of AIP in 2004. The aim of the present study was to determine the frequency and clinical impact of kidney lesions observed in patients with AIP type 1. METHODS: We performed a single-centre retrospective study on a prospectively collected cohort of patients with a histologically proven or highly probable diagnosis of AIP according to the International Consensus Diagnostic Criteria (ICDC) classification. RESULTS: Seventy-one patients with AIP were evaluated. AIP type 1 was diagnosed in 62 (87%) patients. Kidney involvement was present in 17 (27.4%) patients with AIP type 1: 15 (88.2%) males and 2 (11.8%) females. Laboratory and/or imaging signs of kidney involvement were presented at the time of AIP diagnosis in eight (47.1%) patients. In other patients, the onset of kidney involvement occurred between four months and eight years following diagnosis. At the time of the diagnosis of kidney involvement, eight (47.1%) patients showed elevated creatinine, and nine (52.9%) patients showed normal serum creatinine. None of the patients were treated with dialysis. CONCLUSIONS: IgG4-RKD was present in 27.4% of patients with AIP type 1, with male gender predominance. In cases of early diagnosis and cortisone treatment, the clinical course was mild in most cases. Regular laboratory control of renal function should be a part of the follow-up of patients with AIP type 1.

Diagnosis, treatment and long-term outcome of autoimmune pancreatitis in Sweden.

INTRODUCTION: Autoimmune pancreatitis (AIP) is a pancreatic inflammatory process characterized by a strong inflammatory cell infiltration and two histopathologically distinct subtypes: type 1 and type 2. Diagnosis is often challenging and requires a combination of clinical, laboratory and imaging data. AIP can mimic pancreatic tumours leading to unnecessary resections if not correctly diagnosed. Short- and long-term outcomes of AIP have been poorly investigated so far and no large series have been previously reported from Sweden. METHODS: A single-centre, retrospective, cohort study of patients with histologically confirmed or highly probable diagnosis of AIP according to ICDC criteria. Demographic, clinical and radiological characteristics, type of treatment and its outcomes were collected and analysed. RESULTS: Seventy-one patients with AIP (87% with type 1), were evaluated at Karolinska University Hospital between 2004 and 2018; 49% males, mean age 49 years (range 44-53). Among them, 28% were histologically confirmed, 35% presented with jaundice, 22% with acute pancreatitis, 39% had non-specific symptoms such as weight loss or abdominal pain, 84% showed other organ involvement (OOI). Radiologically, 76% showed a focal pancreatic enlargement, 27% diffuse enlargement, 27% signs of acute pancreatitis and 10% of chronic pancreatitis. Overall, 58 patients (81%) underwent treatment with different medications: 46 (79%) cortisone, 7 (12%) azathioprine, 5 (8%) other immunosuppressive drugs. Twenty-six (36%) underwent biliary stenting and 12 (16%) were given surgery. In total, 47% of patients developed pancreatic exocrine insufficiency (PEI), of whom 76% had a severe form (faecal elastase-1 < 100 µg/g) and 21% of patients developed diabetes mellitus (pancreatic endocrine insufficiency), of whom 73% required insulin. CONCLUSIONS: AIP is a challenging disease for diagnosis and treatment. Cortisone treatment is generally successful and provides clinical remission in the large majority of patients (>90%). In the further course of the disease, a considerable number of patients develop PEI and diabetes. Only one-quarter of patients exhibit on imaging the characteristic "sausage-like" pancreas (diffuse enlargement), approximately three-quarters had a focal mass that could be misdiagnosed as pancreatic malignancy.

Pancreatic MRI for the surveillance of cystic neoplasms: comparison of a short with a comprehensive imaging protocol.

OBJECTIVES: The study aims were to evaluate: (1) whether a short-protocol (SP) MRI for the surveillance of pancreatic cystic neoplasms (PCN) provides equivalent clinical information as a comprehensive-protocol (CP), and (2) the cost reduction from substituting CP with SP for patient surveillance. METHODS: This retrospective study included 154 consecutive patients (median age: 66, 52 % men) with working-diagnosis of PCN and available contrast-enhanced MRI/MRCP. Three radiologists evaluated independently two imaging sets (SP/CP) per patient. The CP included: T2-weighted (HASTE/MRCP), DWI and T1-weighted (chemical-shift/pre-/post-contrast) images [acquisition time (AT) ≈ 35 min], whereas the SP included: T2-weighted HASTE and T1-weighted pre-contrast images (AT ≈ 8 min). Mean values of largest cyst/main pancreatic duct diameter (DC/DMPD) were compared. Agreement regarding presence/absence of cystic/MPD mural nodules (MNC/MNMPD), inter-observer agreement and cost differences between SP/CP were calculated. RESULTS: For DC and DMPD, mean values with SP/CP were 21.4/21.7 mm and 3.52/3.58 mm, while mean differences SP-CP were 0.3 mm (p = 0.02) and 0.06 mm (p = 0.12), respectively. For presence/absence of MNC and MNMPD, SP/CP coincided in 93 % and 98 % of cases, respectively. Inter-observer agreement was strong for SP/CP. SP-cost was 25 % of CP-cost. CONCLUSIONS: For the surveillance of PCN, short-protocol MRI provides information equivalent to the more time-consuming and costly comprehensive-protocol. KEY POINTS: • Pancreatic cystic neoplasms (PCN) are increasingly diagnosed in the general population. • Multiple imaging controls are recommended for the surveillance of patients with PCN. • Short and comprehensive MRI-protocols are equivalent for decision-making in PCN under surveillance. • Evaluation of imaging risk factors in PCNs is comparable with both MRI-protocols. • Use of the short MRI-protocol may rationalise healthcare resources.