Important LCH III Study Update February 2008 While the LCH-III is closed to new patients in North America, the study remains open to collect patient follow-up forms from existing study participants. To request the Progress Report and/or the Scientific Review of the LCH-II Manuscript, complete the Histiocyte Society Information Request form.   Clinical Trials, Treatment Guidelines and References For further information and instructions on how to obtain the trials, guidelines and references listed below, please fill out the Histiocyte Society Information Request form. LCH Evaluation and Treatment Guidelines The LCH evaluation and treatment guidelines were approved  in April 2009. These clinical guidelines have been developed by expert members of the Histiocyte Society and are intended to provide an overview of currently recommended treatment strategies for LCH. HLH-2004 The HLH-2004 protocol opened on January 1, 2004, and is designed for patients with inherited, familial hemophagocytic lymphohistiocytosis (FHLH) and nonfamilial hemophagocytic lymphohistiocytosis (HLH). This protocol is based on the HLH-94 protocol with minor therapeutic modifications.   LCH-S-2005 This clinical trial was created in December 2005 and is now open for enrollment.  It is an international phase II study evaluating the combination of Cladribine (2-CdA) and Cytarabine Cytosine-arabinoside (Ara-C) in LCH patients who fail to respond to front-line chemotherapy AND who have risk organ involvement. LCH-HCT This clinical trial was designed in 2006 with the primary objective of determining the overall and disease free survival at 1 and 3 years after reduced intensity hematopoietic cell transplantation (RI-HCT) in poor risk patients with Langerhans Cell Histiocytosis.