Hepatitis C is not easily diagnosed because of its atypical symptoms. On the other hand, Hep-C can be easily proven : one only need look for anti-HCV antibodies or viral DNA in the blood. An infection with the Hepatitis C-virus (HCV) can be overcome with full recovery in 30% of all cases. The other 70% of most cases develop chronic hepatitis with an unfortuntate final prognosis: liver cirrhosis or cancer.
SLE (systemic lupus erithematosus) is not that easily detected or diagnostically proven. Lupus is a chronic inflammatory autoimmune disease that attacks almost all the body's organs. There are several diagnostic criteria ,both clinical and laboratorial, that are used for diagnosing lupus. In some [atypical] cases, lupus is difficult to prove. Lupus can also damage the liver but not as severe as during Hepatitis C.
Scleroderma is also a chronic inflammatory autoimmune disease with an unknown etiology, or cause. Some clinical and laboratory diagnostic criteria for scleroderma exist, but scleroderma is harder diagnose than lupus. Sometimes even a skin biopsy is requested to confirm scleroderma.
You can consult a rheumatologist for an expert opinion.