TY - JOUR T1 - TYpe d (delta) hepatitis AU - Caredda F, Antinori S, Moroni M Y1 - 1989/12/01 N1 - 10.1001/jama.1989.03430210033013 JO - JAMA SP - 2995 EP - 2996 VL - 262 IS - 21 N2 - To the Editor.—  Dr Hoofnagle1 recently presented in JAMA an excellent comprehensive review of the field of type D (delta) hepatitis. However, we believe that some new findings deserve consideration. The author states that "delta hepatitis occurs only in patients who have HBsAg [hepatitis B surface antigen] in serum" and that "the clinician should consider testing for anti-HDV [antibody to hepatitis delta virus] in any patient with acute or chronic hepatitis who is tested HBsAg positive." This statement is suggested by the fact that HDV is a defective virus unable to replicate without the concomitant hepatitis B virus infection and apparently was confirmed by the negative results obtained in patients with acute HBsAg-negative hepatitis.2 Nevertheless, the interference of HDV infection on hepatitis B virus replication is a well-known phenomenon, and a few case reports have shown that HDV can be expressed in the absence of detectable HBsAg in SN - 0098-7484 M3 - doi: 10.1001/jama.1989.03430210033013 UR - http://dx.doi.org/10.1001/jama.1989.03430210033013 ER -