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Transfusion-transmitted virus DNA in serum, tear and aqueous humour of patients undergoing cataract operation


Dr Sinan Emre, Inonu University Medical Faculty, Turgut Ozal Medical Center, Research Hospital, Ophthalmology Department, TR-44280 Malatya, Turkey. Email:


Purpose:  Transfusion-transmitted virus (TTV) is a novel non-enveloped, single-stranded DNA virus with unclear pathogenesis throughout the world. Many studies were conducted to determine this virus in various body fluids and different primer sets have been tested for accurate diagnosis. This study aimed to collect data on the prevalence of TTV in serum, tear and aqueous humour of patients undergoing planned cataract surgery and to determine efficacy of three different polymerase chain reaction (PCR) techniques.

Methods:  A total of 72 specimens (24 each of serum, tear and aqueous humour specimens) were collected from 24 patients (11 male and 13 female) having age-related cataract. The patients did not have any other ocular pathology. TTV DNA was investigated by three different PCR methods: a seminested PCR performed with Okamato's primers, a one-step PCR performed with degenerative Takashi's primers and a commercial real-time PCR system.

Results:  TTV DNA was detected in 20 (83.3%) of the 24 serum specimens by the one-step PCR and real-time PCR system. However, seminested PCR yielded a positivity rate of 25%. TTV DNA positivities of the one-step PCR and the real-time PCR system were 33.3% and 66.6% of the 24 tear specimens, respectively. Seminested PCR did not yield positive result in these specimens. From aqueous humour specimens, TTV DNA was detected in 3 (12.5%) of the 24 specimens only by the real-time PCR. TTV DNA positivity of seminested PCR was significantly low in all specimens.

Conclusions:  TTV DNA was detected in serum, tear and aqueous humour of patients undergoing cataract surgery, supporting the idea that this virus can be detected almost all of the body fluids but at different rates under various PCR conditions and primer sets. Using commercial real-time PCR significantly increased the TTV DNA positivity.