title: Acquired deficiency in C1-inhibitor associated with signet ring cell gastric adenocarcinoma: a probable connection of antitumor-associated antibodies, hemolytic anemia, and complement turnover.
abstract: BACKGROUND
  Acquired deficiency in C1-inhibitor (C1-INH) associated with malignancy is often asymptomatic because clinical manifestations are not dependent on a critical complement threshold (in contrast to hereditary C1-INH deficiency). Increased complement consumption involving different kinds of antibodies is the postulated mechanism for this disease, but other factors must play an important role.
  
  
  METHODS
  A 76-year-old woman with unremarkable medical history experienced three episodes of angioedema over 6 months. Investigations revealed a complement profile characteristic of acquired deficiency in C1-INH, a hemolytic anemia, and a signet ring cell adenocarcinoma (linitis plastica). A gastrectomy and a splenectomy were performed. The postoperative course was characterized by a complete disappearance of the symptoms of angioedema and hemolytic anemia. A local recurrence of the tumor 5 months later could not be resected. The patient died 17 months after the initial surgery was performed.
  
  
  RESULTS
  Quantitative and functional analyses of the complement factors showed persistent excessive complement consumption. Markers of hemolytic anemia disappeared after tumor removal but recurred in the second part of the disease evolution. Immunohistochemical findings in tumor tissue showed loss of normal blood group antigens but expression of Lea antigen, as well as C1q deposition.
  
  
  CONCLUSIONS
  To explain the whole clinical and laboratory picture, we hypothesize a connection between tumor immunohistochemical profile, complement consumption, and hemolytic anemia. Tumor cell surface antigens might lead to a permanent but asymptomatic complement consumption that is worsened and becomes clinically manifest by superimposed hemolytic anemia caused by cross-reactive antibodies to newly expressed blood group antigens on tumor cells. This hypothesis should be confirmed by other observations.
authors: Department of Internal Medicine, University Hospital (CHUV), Lausanne, Switzerland.
authors: J B
authors: JB
authors: Wasserfallen
authors: P
authors: P
authors: Spaeth
authors: L
authors: L
authors: Guillou
authors: A R
authors: AR
authors: Pécoud
mesh_terms: D000368:Aged; D000743:Anemia, Hemolytic / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D000799:Angioedema / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D000912:Antibodies, Neoplasm / Q000097:blood*; D018279:Carcinoma, Signet Ring Cell / Q000150:complications* / Q000175:diagnosis / Q000473:pathology; D002908:Chronic Disease; D003174:Complement C1 Inactivator Proteins / Q000032:analysis / Q000172:deficiency*; D003165:Complement System Proteins / Q000032:analysis*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000473:pathology
chemical_list: D000912:Antibodies, Neoplasm; D003174:Complement C1 Inactivator Proteins; D003165:Complement System Proteins