Differential Diagnosis
- Single most likely diagnosis
- Systemic Lupus Erythematosus (SLE): The presence of a high-titer positive ANA (1:320) with a reticular pattern, mild proteinuria, and normocytic anemia are all consistent with SLE. The mildly elevated ALT could be due to liver involvement in SLE.
- Other Likely diagnoses
- Autoimmune Hepatitis: Although hepatitis screening is negative, autoimmune hepatitis can present with mildly elevated liver enzymes and positive ANA. The absence of significant bilirubin elevation and the presence of other autoimmune features (ANA positivity, proteinuria) make this a consideration.
- Mixed Connective Tissue Disease: This condition overlaps with SLE, systemic sclerosis, and polymyositis/dermatomyositis, and can present with a positive ANA, mild liver enzyme elevation, and anemia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Hepatitis B or C (despite negative screening): False negatives can occur, especially in early infection or with certain assay limitations. These infections can lead to severe liver disease if not treated.
- Hemophagocytic Lymphohistiocytosis (HLH): Although rare, HLH can present with anemia, elevated liver enzymes, and a positive ANA. It is a life-threatening condition requiring prompt diagnosis and treatment.
- Paroxysmal Nocturnal Hemoglobinuria (PNH): This condition can cause normocytic anemia, elevated liver enzymes, and can be associated with a positive ANA. PNH can lead to severe thrombotic events if not diagnosed and treated.
- Rare diagnoses
- Primary Biliary Cholangitis (PBC): Although more common in women, PBC can present with mildly elevated liver enzymes and a positive ANA. The absence of significant bilirubin elevation and the presence of anemia make this a less likely but possible diagnosis.
- Sjögren's Syndrome: This autoimmune condition can present with a positive ANA, mild liver enzyme elevation, and anemia, although it is more commonly associated with sicca symptoms (dry eyes and mouth).