Posible enfermedad por IgG4 asociada con alogenosis iatrogénica. Caso clínico / Possible IgG4 disease associated with iatrogenic allogeneic disease. Case report

Presentamos un caso de paciente con alogenosis iatrogénica que tras ser intervenido quirúrgicamente, cursa con pancreatitis aguda de etiología no precisada con valores séricos elevados de inmunoglobulina 4 (IgG4). La asociación con la buena respuesta terapéutica al tratamiento esteroideo unida al antecedente de síndrome autoinmune inflamatorio sistémico inducido por adyuvantes, insuficiencia renal crónica con biopsia que reportó atrofia tubular severa con fibrosis, pseudotumores intestinales, pérdida de peso, diarrea y dolores óseos asociados, hizo pensar que el agente desencadenante de la respuesta inmunológica pudo ser el estímulo que elevó la IgG4 sérica llevando al diagnóstico de posible enfermedad relacionada con IgG4.(AU)

We present a case with iatrogenic allogenosis who, after undergoing surgery, presented acute pancreatitis of unspecified etiology with elevated serum levels of immunoglobulin 4 (IgG4). The association with a good therapeutic response to steroid treatment coupled with a history of adjuvant-induced systemic inflammatory autoimmune syndrome, insufficiency chronic kidney disease with biopsy that reported severe tubular atrophy with fibrosis, intestinal pseudotumors, weight loss, diarrhea and associated bone pain, suggested that the immunogenic agent that triggers the immune response could be the stimulus to raise serum IgG4 leading to the diagnosis of possible IgG4 disease.(AU)

Sialoadenitis esclerosante asociada a enfermedad por IgG4: reporte de un caso / Sclerosing sialadenitis associated with IgG4 disease: case report

Las enfermedades relacionadas con IgG4 (ER-IgG4) son entidades fibroinflamatorias e inmunomediadas, caracterizadas por la afección multiorgánica, con la formación de pseudotumores que provocan lesión tisular y daño orgánico subsecuente. Se describe el caso de un paciente de 43 años que presentó sialoadenitis esclerosante y cumplió todos los criterios diagnósticos de enfermedad relacionada con IgG4.

IgG4-related diseases (IgG4-RD) are fibroinflammatory immune-mediated entities characterized by multiorgan involvement with the development of pseudotumors that cause tissue injury and subsequent organ damage. We describe the case of a 43-year-old man who presented sclerosing sialadenitis and fulfilled the diagnostic criteria for IgG4-related disease.

Hipofisitis linfoplasmocitaria con expresión de IgG4 / IgG4- related lymphoplasmacytic hypophysitis

La hipofisitis linfoplasmocitaria con expresión de inmunoglobulina G4 (IgG4) es una entidad de reciente conocimiento. Pertenece al grupo de enfermedades relacionadas a IgG4 (IgG4-RD, del inglés: IgG4-related disease), donde uno o varios órganos pueden estar comprometidos, con síntomas compresivos u obstructivos, o disfuncionalidad por infiltración celular. La hipófisis puede estar afectada en forma aislada. Clínicamente, se presentan con diabetes insípida, hipopituitarismo y/o síntomas de masa ocupante selar, siendo los principales diagnósticos diferenciales los adenomas selares no secretantes, y otros tipos de hipofisitis. Para arribar al diagnóstico de este tipo patología es necesaria la presencia de una imagen de agrandamiento selar o engrosamiento del tallo pituitario en la resonancia magnética nuclear, una histopatología característica con inmunomarcación positiva para IgG4 en más de 10 células plasmáticas por campo de gran aumento y la presencia de IgG4 sérica elevada. Tienen una excelente respuesta a glucocorticoides, por lo que una sospecha diagnóstica oportuna evitaría una cirugía innecesaria en la mayoría de los pacientes con esta entidad.

Immunoglobulin G4 (IgG4)-related lymphoplasmacytic hypophysitis is a recently known entity. It belongs to the IgG4-related diseases (IgG4-RD), in which one or more organs may be involved, with compressive or obstructive symptoms, or dysfunctionality due to cellular infiltration. The pituitary gland can be isolatedly affected. Clinically, lymphoplasmacytic hypophysitis presents with diabetes insipidus, hypopituitarism and/or symptoms of an occupying sellar mass, being the non-secreting sellar adenomas and other types of hypophysitis the main differential diagnosis. In order to reach the diagnosis, the presence of pituitary enlargement or pituitary stalk thickening on an MRI scan, a distinctive histopathology with positive for IgG4 immunostaining in more than 10 plasma cells per high-powerfield, and elevated serum IgG4 levels, confirms this type of hypophysitis. As this entity has an excellent response to glucocorticoids, the diagnosis suspicion may avoid an unnecessary surgery in most patients.

IgG4-related disease, retrospective histopathological diagnosis. Prevalence in a University Hospital.

INTRODUCTION: IgG4 related diseases (IgG4-RD) are characterized mainly by organic dysfunction and inflammation with lymphoplasmacytic cells infiltration. METHODS: We conducted a retrospective study. We analyzed patients with a diagnosis of IgG4-RD through histopathologic registries. We divided the study into three phases: (i)extraction of data from the registries of the Pathology Department, including specimens reported with: non-specific inflammation with plasmatic cell infiltration, inflammatory pseudo-tumors and storiform fibrosis, and excluding any report of cancer or infection; (ii)from the selected specimens, three pathologists microscopically re-analyzed these biopsies and included only those who had at least two of the inclusion criteria cited above; (iii)finally, immunostaining was performed in the specimens selected in the second phase. The selected biopsies were catalogued as compatible for IgG4-RD if they had at least 3 inclusion criteria and as probable if they had 2 inclusion criteria. RESULTS: On the first phase of the study we analyzed 23,720 biopsies, from which we included 71 and excluded 29 specimens; the rest of the specimens (n=41) underwent immunostaining. From the biopsies included, 41.4% (n=17/71) were positive to IgG4, with the most common histological diagnosis for the positive specimens being granulomatous mastitis, which represented 12.1% of the specimens catalogued initially as probable. The rest of the positive biopsies were from aortitis, dacrioadenitis and/or sialoadenitis, lung pseudo-inflammatory tumor, pericarditis and chronic pancreatitis. CONCLUSIONS: The suspicion of IgG4 related disease should not be based solely on clinical manifestations or serology. In the present study we confirm the characteristic changes of IgG4-RD in patients without initial clinical suspicion.

¹8F-FDG PET-CT usefulness in extra-pancreatic involvement in IgG4 related diseases.

IgG4-related diseases are a group of recently identified entities that include disorders that were previously known by other names, such as Mikulicz disease, Küttner's tumor, Riedel thyroiditis, among others, as well as some new ones described in the last years. These pathologies are a challenge for the medical community in terms of diagnosis and characterization due to their wide spectrum of clinical presentation. Functional imaging can provide a new approach to the comprehension of physiopathology, staging and targeting site of biopsy of IgG4-related diseases. In this clinical note, we describe five patients who underwent ¹8F-FDG PET-CT and correlate their findings with previous reports.