An prospective / retrospective multicenter observational study whose objectives are to understand the interactions between hepatitis c virus and Non Hodgkin lymphomas. The characteristics , evolution and treatment of diseases will be observed from the study.

Main objectives are:

• Description of the clinical and histological characteristics, treatment and evolution of these NHL.
• Study their physiopathology by immunological, virologic and molecular studies.

The study included prospective or retrospective patients with B- Cell Non-Hodgkin lymphomas (NHL) associated with chronic hepatitis C. The patients are diagnosed or in remission of lymphoma, in relapse or failure of treatments.

The enrolment period is 6 years and the total study lasts 8 years.

• "Prospective patients" are followed every 6 months during one year, and all the years during 2 or 5 years.
• "Retropective patients" are followed all the years during 2 or 5 years. At each follow-up, a blood sample of 50ml is withdrawn allowing ancillary studies.

The enrollment is estimated at 140 patients.

Inclusion Criteria:

• Patients with evolving NHL whatever its histological type
• At diagnosis or relapse or failure previous treatments stopped over 3 months
• Patients with HCV infection with positive quantitative viral load
• 18 years or more of age
• Life expectancy greater than 6 months
• Signed and informed consent
• Benefit from social security

Exclusion Criteria:

• Active uncontrolled infection (out hepatitis C)
• HIV (Human immunodeficiency virus) infection
• Severe psychiatric history

Adult patients with HCV infection with positive viral load and a B-cell NHL.