title: An update on renal involvement in hemophagocytic syndrome (macrophage activation syndrome).
abstract: BACKGROUND
  Hemophagocytic syndrome (HPS) is mainly characterized by massive infiltration of bone marrow by activated macrophages and often presents with pancytopenia. Thrombotic microangiopathy (TMA) is also present with thrombocytopenia and renal involvement. Both conditions could coexist with each other and complicate the condition.
  
  
  METHODS
  Directory of Open Access Journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science with keywords relevant to; Hemophagocytic syndrome, macrophage activation syndrome, interferon-gamma and thrombotic microangiopathy, have been searched.
  
  
  RESULTS
  Viral infection, rheumatologic disease and malignancies are the main underlying causes for secondary HPS. calcineurin inhibitors and viral infections are also the main underlying causes of TMA in transplant recipients. In this review, we discussed a 39-year-old male who presented with pancytopenia and renal allograft dysfunction. With the diagnosis of HPS induced TMA his renal condition and pancytopenia improved after receiving intravenous immunoglobulin (IVIG) and plasmapheresis therapy.
  
  
  CONCLUSIONS
  HPS is an increasingly recognized disorder in the realm of different medical specialties. Renal involvement complicates the clinical picture of the disease, and this condition even is more complex in renal transplant recipients. We should consider the possibility of HPS in any renal transplant recipient with pancytopenia and allograft dysfunction. The combination of HPS with TMA future increases the complexity of the situation.
authors.affiliation: Department of Pathology, Al-Zahra Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Haydarali
authors.initials: H
authors.lastname: Esmaili
authors.affiliation: Department of Pathology, Al-Zahra Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Elmira
authors.initials: E
authors.lastname: Mostafidi
authors.affiliation: Department of Pathology, Al-Zahra Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Mehramuz
authors.affiliation: Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Ardalan
authors.affiliation: Pediatric Neurosurgery Unit, University of Alabama, Birmingham, USA.
authors.forename: Mohammadali
authors.initials: M
authors.lastname: Mohajel-Shoja
keywords: Hemophagocytic syndrome; Interferon-gamma; Macrophage activation syndrome; Thrombotic microangiopathy