title: Secondary hemophagocytic lymphohistiocytosis in children: an analysis of etiology and outcome.
abstract: Fifty-two pediatric patients were diagnosed with secondary hemophagocytic lymphohistiocytosis (HLH) at the Department of Pediatrics, Siriraj Hospital between 1989 and 1998. Of these, 15 were infection-associated (IAHS), 25 were malignancy-associated (MAHS) and 12 were idiopathic HLH. Causative organisms for IAHS were Salmonella (3), Staphylococcus (2), enterobactor (2), dengue virus (3), malaria (2) and one each of Ebstein Barr virus (EBV), Serratia marcesens and Penicillium maneffei. Unlike those reported in adults and in the Western literature, 47 of 52 children in the present series were immunocompetent hosts. In addition, the proportion of MAHS was higher than expected (48.1%). Twenty-two of 25 MAHS presented with hemophagocytic syndrome and were subsequently found to have malignant diseases. Sixty per cent of MAHS (15 cases) were associated with non-Hodgkin's lymphoma (NHL), mainly T-cell. Other malignancies included acute leukemias (7) MDS (1), Langerhans cell histiocytosis (1) and histiocytic sarcoma (1). Treatment approaches were specific therapy for individuals with known causes. Supportive treatment with blood components transfusions, steroid, intravenous immunoglobulins (IVIG), and chemotherapeutic agents, mainly vinblastine and etoposides, were used in indicated cases. Of the 52 cases, 15 (28.8%) had a fatal outcome during the acute phase, and other 4 died of their subsequent malignant diseases. There was a statistically significant association between poorer prognosis and patients' age < 3 years (p= 0.004) or MAHS (p=0.005).
  
  
  CONCLUSIONS
  Secondary HLH is not uncommon in Thai children who are immunocompetent. Malignancies, particulary NHL, are highly suspicious especially for cases not responsive to conventional therapy. Poor prognostic factors are age less than 3 years and MAHS.
authors.forename: Gavivann
authors.initials: G
authors.lastname: Veerakul
authors.forename: Kleebsabai
authors.initials: K
authors.lastname: Sanpakit
authors.forename: Voravarn S
authors.initials: VS
authors.lastname: Tanphaichitr
authors.forename: Chularatana
authors.initials: C
authors.lastname: Mahasandana
authors.forename: Nongnapa
authors.initials: N
authors.lastname: Jirarattanasopa
mesh_terms: D017677:Age Distribution; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D000970:Antineoplastic Agents / Q000008:administration & dosage; D001424:Bacterial Infections / Q000150:complications*; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D005260:Female; D019337:Hematologic Neoplasms / Q000150:complications*; D015616:Histiocytosis, Non-Langerhans-Cell / Q000188:drug therapy* / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage; D015994:Incidence; D007223:Infant; D008297:Male; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D013785:Thailand / Q000453:epidemiology; D016896:Treatment Outcome; D014777:Virus Diseases / Q000150:complications*
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D016756:Immunoglobulins, Intravenous