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• Antoine J. Zgheib, Antoine T. Aoun (Author)

  IgG4-Related Disease of the Liver and Kidney: Diagnostic Integration for Emergency Medicine

  IgG4-related disease (IgG4-RD) is a chronic fibro-inflammatory condition triggered by autoimmunity that can affect multiple organ systems, with the hepatobiliary tract and kidneys being two of the most commonly involved. Given that the clinical and imaging presentation of IgG4-RD is similar to that seen in cases of malignancy, infections, and other autoimmune conditions, diagnosis is difficult, especially in the setting of acute care when delayed diagnosis could result in the performance of unnecessary invasive tests and improper treatment. This paper reviews the recent advances in diagnosis and management of the disease, specifically classification, imaging, pathology, biomarkers, and treatment modalities for IgG4 related disease affecting the biliary tree and kidney. A structured review of the literature in PubMed/MEDLINE, Embase, and Cochrane Library was performed for the period up until November 2025, including mainly the literature from 2012 to 2025 and landmark earlier papers. IgG4-RD is shown to primarily involve men above 50 years of age, typically manifesting itself as IgG4-related sclerosing cholangitis in the hepatobiliary system and as tubulointerstitial nephritis in the kidneys; however, glomerulonephritis and inflammatory pseudotumors can occur. The diagnosis of IgG4-RD is achieved by using the combination of clinical findings with distinct radiologic findings, high levels of serologic parameters, and histopathological evidence of lymphoplasmacytic infiltrate, storiform fibrosis, obliterative phlebitis, and the increased number of plasma cells positive for IgG4. Recently, circulating plasmablasts have been shown to be a better biomarker than serum IgG4 in certain patients. Induction therapy is based on glucocorticoids, while rituximab is used as an efficient steroid-sparing alternative in case of recurrences or refractoriness to corticosteroids. The importance of early diagnosis of IgG4-RD in order to differentiate this condition from malignancies and inflammatory diseases and achieve successful treatment cannot be underestimated.

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  Antoine Zgheib (Author)

  Human Metapneumovirus Infection in an Elderly Patient Receiving Maintenance Hemodialysis with Chronic Obstructive Pulmonary Disease (COPD): A Case Report

  Human metapneumovirus (hMPV) is an important cause of acute infections of the respiratory system affecting young children, older adults, and immunocompromised individuals. Patients suffering from chronic obstructive pulmonary disease (COPD) and end-stage renal disease (ESRD) receiving maintenance hemodialysis represent a particularly vulnerable population, yet published reports describing hMPV infection in dialysis patients remain limited.

  A 70-year-old male with a background of COPD, hypertension, and diabetic nephropathy with a maintenance hemodialysis regimen presented with a four-day history of fever, cough with rhinorrhea, myalgias, and dyspnea. He was immunized against influenza, COVID-19, and RSV. Physical examination showed signs of mild hypoxemia with diffuse crackles and expiratory wheezing, without evidence of consolidation. The patient’s chest radiograph showed chronic obstructive changes. Triplex RT-PCR for influenza virus, RSV, and SARS-CoV-2 was negative. However, a multiplex RT-PCR respiratory panel identified hMPV. He had a good response to supportive care with oxygen supplementation, bronchodilator therapy, and continuation of his scheduled hemodialysis regimen, with subsequent discharge after five days.

  The above-mentioned case shows how crucial it is to consider the possible hMPV infection in differentiating the cause of respiratory complaints in dialysis patients. This infection, even being a relatively mild one, can have serious consequences from the point of view of infection control in dialysis units due to close contact between patients and their frequent use of common medical devices. This observation highlights the clinical significance of hMPV infections in hemodialysis patients.