A 50 year old caucasian woman presents with a 3 month history of mild arthralgia, skin rash particularly at her extremities and Raynauds phenomenon. She has an eGFR of 55mls/min/1.73m² and 1.3g/24 hours of proteinuria. C3 is normal but C4 is low. A skin and a renal biopsy is shown below. The renal biopsy is reported on light microscopy as showing a mesangiocapillary (membranoproliferative) glomerulonephritis. She was previously fit and well though did fracture her femur which required hospitlisation, blood transfusion whilst on holiday in Egypt 10 years ago.
Whats the most likely diagnosis?