Nefropatía por enfermedad relacionada a IGG4 / Nephropathy due to IGG4-related disease

IgG4-related disease (ER-IgG4) is a group of systemic fibro-inflammatory diseases, whose renal involvement is rare and difficult to diagnose. Diagnosis is usually made by serological and histological studies. Treatment is based on systemic corticosteroids. The renal prognosis is determined by the patient's comorbidities and the degree of fibrosis in the renal biopsy. We present the case of an elderly patient with exacerbated chronic kidney disease, whose study showed nephropathy associated with ER-IgG4.

La enfermedad relacionada a IgG4 (ER-IgG4) es un grupo de enfermedades fibro-inflamatorias sistémicas, cuya afectación renal es poco frecuente y de difícil diagnóstico. Habitualmente el diagnóstico se realiza mediante estudios serológicos e histológicos. El tratamiento se basa en corticoides sistémicos. El pronóstico renal está determinado por las comorbilidades del paciente y el grado de fibrosis en la biopsia renal. Se presenta el caso de un paciente adulto mayor con enfermedad renal crónica reagudizada, cuyo estudio demostró nefropatía asociada a ER-IgG4.

Adult ocular adnexal xanthogranulomatous disease associated with immunoglobulin G4-related disease: an unusual association.

Adult-onset xanthogranuloma (AOX) and immunoglobulin G4-related disease (IgG4-RD) are uncommon fibrosing conditions that may exhibit localized ocular manifestations and occasionally systemic symptoms. These conditions exhibit overlapping clinical and histological features, suggesting a potential correlation between them, although their exact relationship remains unclear. This paper presents the case of a black male patient exhibiting typical histological indications of both AOX and IgG4-RD. The patient responded positively to corticosteroid treatment.

Una inusual causa de estrechez de la vía aérea laringotraqueal / An unusual cause of laryngotracheal airway narrowing

La enfermedad relacionada con inmunoglobulina (Ig) G4 es una enfermedad de reciente conocimiento que puede comprometer cualquier órgano teniendo preferencias por ciertas regiones del cuerpo, donde la región de cabeza y cuello es uno de sus principales puntos afectados, pudiendo comprometer tanto la órbita, glándulas salivales, glándulas lagrimales, glándula tiroides, cavidades paranasales, hueso temporal, faringe y laringe. Este último órgano es infrecuentemente comprometido, solo existiendo 12 casos registrados en la literatura antes de la publicación de este escrito. Presentamos un caso de una mujer de 49 años con historia de disnea frente a esfuerzo, diagnosticándose una estenosis subglótica la cual fue manejada quirúrgicamente con una reconstrucción laringotraqueal. En el estudio histopatológico se evidenció histología compatible con enfermedad relacionada con IgG4, por lo que se inició tratamiento médico con corticotera- pia oral por un lapso de 2 meses en conjunto con inmunología. Paciente luego de 4 años de seguimiento, no ha presentado recaídas, manteniendo un lumen subglótico adecuado.

Immunoglobulin (Ig) G4-related disease is a medical condition of recent knowledge that can compromise any organ, having preferences for certain regions of the body, where the head and neck region is one of the main affected points, being able to affect orbit, salivary glands, lacrimal glands, thyroid gland, paranasal cavities, temporal bone, pharynx and larynx. The latter is infrequently compromised, with only 12 cases registered in the literature before the publication of this writing. We present a case of a 49-year-old woman with a history of exertional dyspnea, diagnosed with a sub- glottic stenosis which was managed surgically with laryngotracheal reconstruction. The histopathological study revealed histology compatible with IgG4-related disease, so medical treatment with oral corticosteroid therapy was started for a period of 2 months in conjunction with immunology. After 4 years of follow-up, the patient has not presented relapses, maintaining an adequate subglottic lumen.

Enfermedad relacionada a IgG4. Serie clínica de pacientes chilenos / IGG4-related disease. Report of 52 patients

BACKGROUND: IgG4-related disease (IgG4 RD) is an immune-mediated fibro-inflammatory disorder, with tissue infiltration of IgG4+ plasma cells. It causes pseudotumors, tumors, and a wide spectrum of clinical manifestations. AIM: To report the clinical, laboratory, histopathological and treatment characteristics of a group of Chilean patients with IgG4 RD. MATERIAL AND METHODS: Review of medical records of 52 patients aged 18 to 76 years with IgG4 RD seen at six medical centers. RESULTS: Elevated IgG4 serum levels (> 135 mg/dl) were found in 18 of 44 (41%) patients. There was histological confirmation of the disease in 46 patients. The most common sites of involvement were lungs, eyes and kidneys. Eighteen (35%) patients had only one organ involved, 34 (65%) patients had two organs and 13 (25%) patients had three or more organs. The involvement of two organs was significantly more common in men (p < 0.05). In patients with only one organ involvement, the most frequent location was orbital and meningeal. All patients with kidney or lung disease had multiorgan involvement. All patients received corticosteroid therapy, 67% synthetic immunosuppressants, and 16% rituximab. CONCLUSIONS: ER-IgG4 can affect any tissue. Multiorgan involvement was more common in this series, with preference for lungs, eyes and kidneys. An excellent response to steroids is characteristic of the disease, but with a high relapse rate that requires additional immunosuppression.

Immunoglobulin G4-related retroperitoneal fibrosis.

Some patients diagnosed with idiopathic retroperitoneal fibrosis could be reclassified as IgG4-related disease (IgG4-RD). Classification criteria have not been uniform and prevalence of IgG4-related retroperitoneal fibrosis (IgG4-RPF) is unknown in our region. We aimed to describe IgG4-RPF frequency relying on criteria published recently and comparing clinical, histopathologic and radiologic features with non-IgG4-RPF. From January, 2005 to December, 2020, nineteen adults with histopathologic diagnosis of idiopathic retroperitoneal fibrosis were included in a dynamic retrospective cohort at Hospital Italiano de Buenos Aires. Pathology slides were reviewed and immunohistochemistry was performed and assessed for each case. We used classification criteria described in 2019 American College of Rheumatology/European League Against Rheumatism to identify IgG4-RD cases. Ten of 19 patients met criteria for IgG4-RPF. Median age was similar in two subsets (61 versus 55, p = 0.2) and both had male predominance. Three out of 10 patients (p = 0.2) featured other manifestations of IgG4-RD in the IgG4-RPF group, and periaortic fibrosis was the most significant finding in images (p = 0.01). Corticosteroids were mostly used as therapy, followed by azathioprine and rituximab. Most patients did not receive specific treatment. IgG4-RPF patients had dense lymphocytic infiltrate and 8 out of 10 showed storiform fibrosis (p = 0.02). IgG4+ cells/hpf and IgG4/IgG ratio were significantly higher (p = 0.01). Over half of the patients in our cohort met the criteria of IgG4-RPF. New criteria may harmonize the identification of IgG4-RD. As IgG4-RD may be reversible at initial stages, these findings may lead to early recognition, treatment and integral follow-up.

Muchos pacientes con diagnóstico de fibrosis retroperitoneal idiopática (FRI) pueden ser reclasificados como enfermedad relacionada con IgG4 (ER- IgG4). Los criterios diagnósticos no han sido uniformes y la frecuencia de fibrosis retroperitoneal relacionada con IgG4 en nuestra región es desconocida. El objetivo fue describir la frecuencia de ER-IgG4 en pacientes clasificados como FRI y comparar características clínicas, histopatológicas y de laboratorio con aquellos que no reunían criterios de la enfermedad. Se incluyeron 19 adultos en un estudio de cohorte retrospectiva dinámica con diagnóstico anatomopatológico de FRI, en el Hospital Italiano de Buenos Aires, desde enero de 2005 hasta diciembre de 2020. Se revisaron las biopsias y se realizó inmun ohistoquímica en cada una. Se consideró caso al paciente que reunía los criterios de la American College of Rheumatology/European League Against Rheumatism 2019. Diez pacientes reunieron criterios de ER-IgG4. La mediana de edad fue similar en ambos grupos (61 vs. 55, p = 0.2) y en ambos hubo predominio masculino. Tres de 10 pacientes (p = 0.2) tuvieron otras manifestaciones de ER-IgG4 y la fibrosis periaórtica fue el hallazgo más significativo en los estudios por imágenes (p = 0.01). Los corticoides fueron las drogas más utilizadas seguidos por azatioprina y rituximab, pero la mayoría no recibió tratamiento específico. Todos los pacientes con fibrosis retroperitoneal relacionada con IgG4 presentaron infiltrado linfocitario denso y 8/10 fibrosis estoriforme (p = 0.01), así como las células IgG4+/hpf y ratio IgG4/IgG fueron significativamente mayores (p = 0.01). Más de la mitad de los pacientes con FRI cumplieron criterios de ER-IgG4. Los nuevos criterios diagnósticos podrían contribuir a homogeneizar la identificación de ER-IgG4. Dado que esta enfermedad puede ser reversible en estadios tempranos, estos resultados promueven aumentar el conocimiento de la entidad para tratamiento precoz y seguimiento integral.

[IGG4-related disease. Report of 52 patients]. / Enfermedad relacionada a IgG4. Serie clínica de pacientes chilenos.

BACKGROUND: IgG4-related disease (IgG4 RD) is an immune-mediated fibro-inflammatory disorder, with tissue infiltration of IgG4+ plasma cells. It causes pseudotumors, tumors, and a wide spectrum of clinical manifestations. AIM: To report the clinical, laboratory, histopathological and treatment characteristics of a group of Chilean patients with IgG4 RD. MATERIAL AND METHODS: Review of medical records of 52 patients aged 18 to 76 years with IgG4 RD seen at six medical centers. RESULTS: Elevated IgG4 serum levels (> 135 mg/dl) were found in 18 of 44 (41%) patients. There was histological confirmation of the disease in 46 patients. The most common sites of involvement were lungs, eyes and kidneys. Eighteen (35%) patients had only one organ involved, 34 (65%) patients had two organs and 13 (25%) patients had three or more organs. The involvement of two organs was significantly more common in men (p < 0.05). In patients with only one organ involvement, the most frequent location was orbital and meningeal. All patients with kidney or lung disease had multiorgan involvement. All patients received corticosteroid therapy, 67% synthetic immunosuppressants, and 16% rituximab. CONCLUSIONS: ER-IgG4 can affect any tissue. Multiorgan involvement was more common in this series, with preference for lungs, eyes and kidneys. An excellent response to steroids is characteristic of the disease, but with a high relapse rate that requires additional immunosuppression.

Pacientes con compromiso orbitario y renal: Diagnósticos diferenciales poco frecuentes / Patients with orbitary and kidney commitment: Rare differential diagnoses

Se comunica una serie de tres casos clínicos que consultaron al servicio de Reumatología por compromiso orbitario y renal. Uno de ellos presentó pseudotumor orbitario con proteinuria en rango nefrótico; se realizó biopsia y se encontró infiltrado linfoplasmocitario denso y fibrosis estoriforme con inmunohistoquímica: 15 células IgG4+ por campo de alto poder y relación IgG/IgG4 ≤40%, concluyendo diagnóstico de enfermedad relacionada por IgG4. El segundo y tercer caso presentaron compromiso ocular con "ojos de mapache" y lesiones amarillentas en párpados, ambos con proteinuria >500 mg/24 h, con biopsia de piel rojo Congo positiva y birrefringencia verde manzana con luz polarizada. Se discuten distintos diagnósticos diferenciales poco frecuentes a tener en cuenta en estos pacientes.

A series of three cases that consulted the rheumatology service due to orbital and renal involvement is reported. One of them presented orbital pseudotumor with proteinuria in the nephrotic range, a biopsy was performed, finding dense lymphoplasmacytic infiltrate and storiform fibrosis with immunohistochemistry: 15 IgG4 positive cells per HPF and IgG/IgG4 ratio ≤40%, concluding diagnosis of IgG4 related disease. The second and third cases presented ocular involvement with raccoon eyes and yellowish lesions on the eyelids, both with proteinuria greater than 500 mg/24 h, with apple-green birefringence of amyloid on congo red staining. Different rare differential diagnoses to take into account in these patients are discussed.

Serum immunoglobulin free light chains and their association with clinical phenotypes, serology and activity in patients with IgG4-related disease.

The clinical utility of serum immunoglobulin free light chains (sFLC) in IgG4-related disease (IgG4-RD) is unknown. Herein we evaluated their association with clinical phenotypes, serology and activity in patients with IgG4-RD. Cross-sectional study that included 45 patients with IgG4-RD, and as controls 25 with Sjögren's syndrome (SS) and 15 with sarcoidosis. IgG4-RD patients were classified in clinical phenotypes: pancreato-hepato-biliary, retroperitoneum/aorta, head/neck-limited and Mikulicz/systemic; as well as proliferative vs. fibrotic phenotypes. We assessed the IgG4-RD Responder Index (IgG4-RD RI) at recruitment and measured IgG1, IgG4, κ and λ sFLC serum levels by turbidometry. sFLC levels were similar among IgG4-RD, SS and sarcoidosis groups. Regarding the IgG4-RD patients, the mean age was 49 years, 24 (53.3%) were men and 55.5% had activity. Eight (17.7%) belonged to pancreato-hepato-biliary, 6 (13.3%) to retroperitoneum/aorta, 14 (31.1%) to head/neck-limited, 16 (35.5%) to Mikulicz/systemic phenotypes, whereas 36 (80%) to proliferative and 9 (20%) to fibrotic phenotypes. High κ sFLC, λ sFLC and κ/λ ratio were present in 29 (64.4%), 13 (28.9%) and 13 (28.9%) of IgG4-RD patients, respectively. There were no differences in sFLC among IgG4-RD phenotypes. κ sFLC and κ/λ ratio correlated positively with the number of involved organs and IgG4-RD RI. Patients with renal involvement had higher κ sFLC and λ sFLC. The AUC for κ sFLC and λ sFLC, for renal involvement was 0.78 and 0.72, respectively. Active IgG4-RD had higher levels of κ sFLC and more frequently a high κ/λ ratio. The AUC for κ sFLC and κ/λ ratio for predicting active IgG4-RD was 0.67 and 0.70, respectively. sFLC correlated positively with IgG1 and IgG4 levels. sFLC may be useful as a biomarker of disease activity as well as multiorgan and renal involvement. In particular, a high κ/λ ratio may identify patients with active disease.

Pseudotumor retroperitoneal como apresentação de doença relacionada à IgG 4: relato de caso / Retroperitoneal pseudotumor as a presentation of IgG4-related disease: a case report

Apresentamos um caso de doença relacionada à IgG4 devido às suas várias formas de apresentação clínica e dificuldades diagnósticas, objetivando acrescentar à literatura científica essa apresentação atípica. Trata-se de um homem de 65 anos com dor abdominal, febre e sintomas urinários. Exames laboratoriais inocentes para processo infeccioso agudo. Em tomografia computadorizada de abdome, evidenciou-se pseudotumor em região retroperitoneal, envolvendo ureter, veia e artéria ilíacas. Foi submetido à ressecção cirúrgica, tendo sido confirmado o diagnóstico de doença relacionada à IgG4 pela imuno-histoquímica. Iniciou tratamento com glicocorticoide com melhora clínica importante, seguindo em acompanhamento ambulatorial.

This is a case report of IgG4-related disease because of its wide variety of clinical presentations and difficulties in diagnosis, aiming at adding this atypical presentation to scientific literature. It is a case of a 65-year-old man with abdominal pain, fever and urinary symptoms. Laboratory tests were naive for acute infectious processes. In a computed tomography of the abdomen, retroperitoneal pseudotumor involving ureter, and iliac vein and artery was found. The patient underwent surgical resection, and the diagnosis of IgG4-related disease was confirmed by immunohistochemistry. The treatment was begun with glucocorticoids, with important clinical improvement. He was followed in outpatient settings.

Sclerosing Cholangitis Related to IgG4: Not Always a Curable Entity.

IgG4-related disease is a recently-described fibro-inflammatory condition with characteristic histopathological findings in the organs involved. The most commonly affected organs are pancreas, lymph nodes, and retroperitoneum. Liver disease usually involves bile structures and therefore IgG4-related disease is considered a cause of secondary sclerosing cholangitis. One out of three patients with IgG4 sclerosing cholangitis also presents autoimmune pancreatitis, although it can be associated with manifestations in other organs. One of the main features of IgG4-related disease is its good prognosis due to the great response to glucocorticoid therapy. However, relapse of the disease is not uncommon, especially when steroid therapy is decreased or stopped. Rituximab seems to be an effective treatment to achieve remission of the disease. We report the case of a 74 year-old man diagnosed with IgG4-related disease based on increase of serum IgG4 levels, imaging and histopathological findings, with systemic involvement including sclerosing cholangitis. Despite the absence of liver fibrosis at onset, the early use of glucocorticoids and rituximab therapy, the patient presented clinical and analytical deterioration, leading to secondary biliary cirrhosis. In conclusion, this clinical case highlights the importance of prompt diagnosis and therapeutics for sclerosing cholangitis secondary to IgG4-related disease in order to avoid progression of the disease and development of liver cirrhosis, as well as the refractory, aggressive nature of the disease in some cases as this one.

Retroperitoneal fibrosis. Steroid treatment response seems to depend on its association to IgG4 related disease.

Retroperitoneal fibrosis (RF) is part of a rare fibrosclerotic disorder. Oral steroids are the initial treatment. Steroid combination with other immunosupressants is used in refractory cases. Steroids refractoriness has been observed in chronic cases. Some cases of RF represent a manifestation of the IgG4 related disease (IgG4-RD) that is associated to a dramatic response to steroid therapy. It is uncertain if RF́s treatment response differs according to its association with IgG4-RD. We hypothesize that RF́s treatment response to steroids depends on the association with IgG4-RD, thus, we collected and compared clinical data from 10 RF cases; 6 male, mean age 50.6 (±16.15 SD) years. Mean FU was 28 (±25.7 SD) months. According to IgG4 levels, patients were categorized as idiopathic RF (IRF n = 5) or RF-IgG4-RD (n = 5). Therapy response was categorized as complete, partial, stable disease, recurrence or non-response. Nine cases received initial therapy with prednisone; complete response was achieved in 4 RF-IgG4 RD. The remaining 5 cases (1 RF-IgG4RD and 4 IRF) underwent a 2nd line therapy; 4 prednisone + tamoxifen and 1 prednisone + azathioprine. Prednisone + tamoxifen combination achieved complete response in 1 case (RF-IgG4RD), partial response in 1 IRF; in 1 IRF case, disease remained stable and 1 did not respond. The prednisone + azathioprine treatment achieved complete response. At follow-up all patients remained stable and no recurrence was registered. These observations suggest and support the hypothesis that response to steroid monotherapy depends on the association of RF with IgG4, suggesting that IRF cases might benefit from initial combination therapies instead of steroid monotherapy.

Enfermedad por IgG4 multisistémica: a propósito de un caso: revisión de la literatura / Multisystemic IgG4 disease: a case report: literature review

We report a 63-year-old male patient who consulted for a 4-month history of xerophthalmia, xerostomia and cervicalgia, associated with jaundice, choluria, low weight and night sweats. Exams show an obstructive pattern and abdominal ultrasound describes a possible mass in the pancreatic head with secondary dilation of the bile duct. Colangio-MRI (magnetic resonance imaging) confirms a focal pancreatic head lesion that determines intrapancreatic bile duct stenosis, proximal dilation of the bile duct and stenosis of the main pancreatic duct. Pancreatic neoplasia versus autoimmune pancreatitis (PAI) is proposed, complementing a study with a count of IgG subclasses where IgG4 stands out at 1050 mg/dl (normal range: 3.9-86) and computed tomography (CT) of the thorax, abdomen and pelvis, that in addition to the biliary-pancreatic alterations, shows thickening of the vesicular wall, multiple bilateral lesions in the renal parenchyma and peri-aortic soft tissue. Salivary gland biopsy reports lymphoplasmacytic infiltrate characteristic of IgG4 disease. A disease related to IgG4 (ER-IgG4) is diagnosed with pancreatic, renal, biliary, vascular, lymphatic, salivary and lacrimal glands involvement. It is treated with corticoidal therapy, evolving favorably with resolution of the symptomatology and regression of imaging alterations.

Se reporta caso de paciente de sexo masculino de 63 años que consulta por cuadro de 4 meses de xeroftalmia, xerostomía y cervicalgia, asociado a ictericia, coluria, baja de peso y sudoración nocturna. En exámenes destaca pruebas hepáticas con un patrón obstructivo y ecografía abdominal que muestra una posible masa en la cabeza pancreática con dilatación secundaria de la vía biliar. Colangio-resonancia (resonancia magnética-RM) confirma una lesión focal en la cabeza pancreática que determina estenosis del colédoco intrapancreático, dilatación proximal de la vía biliar y estenosis del conducto pancreático principal. Se plantea neoplasia de páncreas versus pancreatitis autoinmune (PAI), complementando estudio con recuento de subclases de IgG donde destaca IgG4 de 1.050 mg/dl (rango normal: 3,9-86) y tomografía computada (TC) de tórax, abdomen y pelvis, que además de las alteraciones bilio-pancreáticas, demuestra engrosamiento de la pared vesicular, lesiones múltiples bilaterales en el parénquima renal y tejido de partes blandas peri-aórtico. Biopsia de las glándulas salivales informa sialoadenitis crónica e inespecífica. Se diagnostica una enfermedad relacionada a IgG4 (ER-IgG4) con compromiso pancreático, renal, biliar, vascular, linfático, de glándulas salivales y lagrimales. Se trata con terapia corticoidal, evolucionando favorablemente con resolución de la sintomatología y regresión de las alteraciones imagenológicas.

[IgG4-related interstitial lung disease]. / Enfermedad pulmonar intersticial por IgG4.

IgG4-related disease is a heterogeneous group of diseases that can affect a single organ or manifest as a systemic disease. We present the case of a 55-yearold female, admitted for dry cough, fever, progressive dyspnea and respiratory failure. Chest CT showed areas of diffuse ground glass, reticular pattern and alveolar consolidation. She received treatment for community acquired pneumonia and systemic corticosteroids with good response. One month later, she was admitted again due to subglottic stenosis, progression of pulmonary infiltrates, and increased palpebral and submaxillary glands volume. Transbronchial and salivary gland biopsies showed infiltration by IgG4. Increased levels of plasma IgG4 were also detected. Immunosuppressive therapy was given with good response.

Enfermedad pulmonar intersticial por IgG4 / IgG4-related interstitial lung disease

Las enfermedades relacionadas con inmunoglobulina G4 (IgG4) son un grupo heterogéneo de cuadros clínicos que pueden afectar un solo órgano o tener compromiso sistémico. Se presenta el caso de una mujer de 55 años, internada por un cuadro de tos seca, fiebre, disnea progresiva e insuficiencia respiratoria. La tomografía de tórax evidenció áreas de vidrio esmerilado difusas, patrón reticular y consolidación alveolar. Recibió tratamiento habitual para neumonía de la comunidad y corticoides sistémicos, presentando buena evolución y otorgándose el alta. Al mes se reinterna por estenosis subglótica, progresión de infiltrados pulmonares y aumento del volumen palpebral y de las glándulas submaxilares. Se realizaron biopsias transbronquial y de glándulas salivales que mostraron infiltración por IgG4. También se detectó aumento de los niveles de IgG4 en plasma. Recibió tratamiento con inmunosupresores evolucionando con buena respuesta.

IgG4-related disease is a heterogeneous group of diseases that can affect a single organ or manifest as a systemic disease. We present the case of a 55-year-old female, admitted for dry cough, fever, progressive dyspnea and respiratory failure. Chest CT showed areas of diffuse ground glass, reticular pattern and alveolar consolidation. She received treatment for community acquired pneumonia and systemic corticosteroids with good response. One month later, she was admitted again due to subglottic stenosis, progression of pulmonary infiltrates, and increased palpebral and submaxillary glands volume. Transbronchial and salivary gland biopsies showed infiltration by IgG4. Increased levels of plasma IgG4 were also detected. Immunosuppressive therapy was given with good response.

Apresentação periorbitária de doença relacionada ao IgG4 / Periorbital presentation of IgG4 related disease

Resumo A doença relacionada ao IgG4 é uma condição imunomediada caracterizada pela presença de lesões com reação inflamatória associada à fibrose e à infiltração linfoplasmocitária rica em plasmócitos tissulares IgG4 positivos, compondo um espectro de doenças fibroproliferativas. A patogênese da DRIgG4 ainda é pouco compreendida e o tratamento é empírico. Relatamos o caso de um homem de 50 anos com lesões amareladas palpebrais associadas a edema local, diagnosticadas previamente como processo alérgico, até que biópsia com estudo imuno-histoquímico e dosagem de IgG4 sérico aventaram a hipótese de doença relacionada ao IgG4. Foi iniciado tratamento com corticoide e rituximabe, observando-se estabilização do quadro e sem apresentação de outras formas clínicas da doença.

Abstract IgG4-Related Disease is an immunomediated condition that is characterized by the presence of inflammatory lesions associated with fibrosis and lymphoplasmacytic infiltration rich in positive IgG4 tissue plasmocytes, forming a spectrum of fibroproliferative diseases. The pathogenesis of IgG4-RD is still poorly understood and the treatment is empirical. We report the case of a 50-year-old man with yellow eyelid lesions associated with local edema, previously diagnosed as an allergic process, until biopsy with immunohistochemical study and serum IgG4 dosage revealed the hypothesis of IgG4 related disease. Treatment with corticoid and rituximab was initiated, showing stabilization of the condition, without presenting other clinical forms of the disease.

Enfermedad sistémica relacionada con IgG4 en un paciente asintomático / Systemic IgG4-related disease in an asymptomatic patient

INTRODUCCIÓN: La enfermedad relacionada con IgG4 (ER-IgG4) es una enfermedad rara, sistémica, fibroinflamatoria con hallazgos histopatológicos característicos en los órganos afectados. CASO CLÍNICO: Paciente masculino, asintomático, de 39 años, con antecedentes de hipotiroidismo, consulta para un control de salud. Las pruebas de laboratorio mostraron anemia con una hemoglobina de 11,7g/dl y Cr de 2,8mg/dl. La orina de 24 hs mostró proteinuria de 3000mg. Una tomografía computada mostró la presencia de un riñón derecho aumentado de tamaño y una imagen nodular de 2,6cm x 1,8cm con bordes irregulares comprimiendo el uréter proximal. Se colocó un pig tail y se obtuvo una biopsia a través de una laparotomía exploratoria. La histología fue compatible con fibrosis retroperitoneal con un gran infiltrado inflamatorio linfoplasmocitario. La fosfatasa alcalina y la ganaglutanil transpeptidasa aumentaron gradualmente hasta valores de 1328U/I y 345U/I respectivamente. El proteinograma mostró gammaglobulinas aumentadas en 1,46mg/dl, con IgG total de 1715mg/dl; En el dosaje de subclases de la IgG4 estaba dentro de límites normales. Se realizó una biopsia hepática que también demostró infiltrado linfoplasmocitario. Ante la sospecha de enfermedad por IgG4, se solicitó inmunohistoquímica en ambas biopsias, que fueron positivas para IgG4. El paciente fue tratado con dosis decrecientes de meprednisona. Tres meses después, todos los parámetros del laboratorio estaban dentro de los límites normales. Los hallazgos del sedimento urinario en nuestro paciente fueron sugestivos de nefritis túbulo intersticial, que se produce en el 30% de los pacientes con ER-IgG4. CONCLUSIÓN: Aunque la presentación inicial de la ER-IgG4 puede ser no específica o más bien sugerir otras enfermedades más comunes, no encontramos ningún caso en la literatura de ER-IgG4 diagnosticada en pacientes asintomáticos. Los sitios más frecuentemente afectados son las glándulas pancreáticas, salivales y ganglios linfáticos. La afectación renal, aórtica, retroperitoneal y pulmonar se describe con frecuencia a nivel hepático, los pacientes pueden presentar pseudotumor inflamatorio, colangitis esclerosante, hepatitis autoinmune o, como en nuestro caso, un infiltrado linfoplasmocitario sutil de IgG4 solo demostrado por la biopsia hepática. Los hallazgos del sedimento urinario en nuestro paciente fueron sugestivos de nefritis tubulointersticial, que se produce en el 30% de los pacientes con ER-IgG4. El diagnóstico tiene tres pilares: radiológico (masas en uno o más órganos), serológico (IgG4 con valores superiores o iguales a 135 mg/Dl) e histológico (fibrosis, infiltrado linfoplasmocitario o más de 10 células plasmáticas IgG4 (+) por campo, con una relación IgG4/IgG total superior al 40%). En nuestro caso, el criterio serológico no se cumplió, sin embargo, este es el menos sensible, ya que hasta el 10-30% de los pacientes con ERIgG4 pueden presentar esta inmunoglobulina dentro rango normal. (AU)

INTRODUCTION: IgG4 related disease (ER-IgG4) is a rare, systemic, fibro-inflammatory disease with characteristic histopathological findings in ffected organs. CLINICAL CASE: This is a 39-year-old asymptomatic male patient with a history of hypothyroidism who consults for his regular health checkup. The laboratory tests showed anemia with a hemoglobin of 11.7g/dL and creatinine of 2.8mg/dL. The 24-hour urine showed proteinuria of 3000 mg. A computed tomography scan showed the presence of an enlarged right kidney and a nodular image of 2.6 cm x 1.8 cm with irregular borders compressing the proximal ureter. A pig tail was placed and a biopsy sample was obtained through an exploratory laparotomy. The histology was compatible with retroperitoneal fibrosis with a large lymphoplasmacytic inflammatory infiltrate. The alkaline phosphatase and gammaglutamil transpepidase gradually increased reaching values of 1328u/i and 345u/I respectively. The proteinogram showed increased gamma globulins of 1.46mg/dl, with a total IgG of 1715mg/dL; IgG4 was within normal limits. A hepatic biopsy was performed which also demonstrated lymphoplasmacytic infiltrate. Upon suspicion of systemic IgG4 disease, an immunohistochemistry was requested in both biopsies samples which showed IgG4 positive immunoblotting. The patient was started with decreasing doses of meprednisone. Three months later, all the laboratory pramenters were within normal limits. CONCLUSIONS: Although the initial presentation of the ER-IgG4 may be non-specific o rather suggest other more common diseases, we have found no cases in the literature of ER-IgG4 diagnosed in asymptomatic patients. The most frequent affected sites are the pancreatic and salivary glands as well as lymph nodes. Renal, aortic, retroperitoneal and pulmonary involvement are frequently described. At the liver level, patients may present with inflammatory pseudotumors, sclerosing cholangitis, autoimmune hepatitis, or, as in our case, with a subtle lymphoplasmacytic IgG4 infiltrate only demonstrated by the liver biopsy. The urinary sediment findings in our patient was suggestive of tubulointerstitial nephritis, which occurs in 30% of patients with ER-IgG4.4 The diagnosis of ER-IgG4 has three pillars: the radiological (masses in one or more organs), the serological (the elevation of IgG4 with values greater than or equal to 135 mg/dL) and the histological (fibrosis, lymphoplasmacytic infiltrate or the presence of more than 10 IgG4 (+) plasma cells per field, with a total IgG4 /IgG ratio greater than 40%). In our case, the serological criterion was not fulfilled in this case, however this is the least sensitive criterion, since up to 10-30% of the patients with ER-IgG4 may present with this immunoglobulin within normal range. (AU)