Case Presentation: A 32-year-old African American male with no past history presented to our hospital with paresthesias, joint pain, and leg swelling of a few weeks’ duration. On examination, fever, tachycardia, maculopapular rash involving both arms, swelling & tenderness in bilateral knee & ankle joints, and pitting edema in bilateral lower extremities were noted. Testing revealed anemia, transaminitis, hypoalbuminemia, elevated inflammatory markers, creatine kinase (CK) levels, benign urine sediment with 1.1g/day proteinuria. Further workup showed deep venous thrombosis in the left leg. Overall, the patient denied any personal or family history of malignancy, autoimmune conditions, recent travel, exposure to pets, toxins, and new medications.Given the constellation of signs & symptoms and systemic involvement, a broad differential of infectious, neoplastic, and autoimmune etiologies was considered. Infectious workup was largely unremarkable. CT chest/abdomen/pelvis did not reveal any masses but disclosed diffuse lymphadenopathy. Due to suspicion of lymphoma, biopsy of an axillary lymph node was performed which demonstrated benign tissue. Simultaneously, the patient also underwent testing for autoimmune conditions which resulted positive for anti-nuclear antibodies (homogenous pattern), rheumatoid factor, double-stranded DNA antibodies, anti Jo-1 antibodies along with low level of C3 complement. Positive lupus anticoagulant was noted as well. Finally, rheumatology was consulted to assist with the diagnosis given the patient’s complex presentation. Features of multiple conditions were considered in the case however, due to lack of diagnostic criteria for myositis, mixed connective tissue disease (absence of ribonucleoprotein antibodies), the patient was finally diagnosed with systemic lupus erythematosus (SLE). High-dose intravenous steroids were initiated resulting in improvement. Further, renal biopsy was performed which revealed class II (mesangial proliferative) lupus nephritis. The patient was finally discharged home on oral steroids and anticoagulants with close outpatient follow-up with a rheumatologist.
Discussion: SLE is an autoimmune connective tissue disorder with a heterogenous presentation and variable clinical course. It can affect multiple organ systems including skin, musculoskeletal, renal, cardiovascular, neuropsychiatric, pulmonary, hematologic etc (1). The American College of Rheumatology provides clinical and immunological criteria to assist with diagnosis of the condition. Anti Jo-1antibody is a type of myositis-specific autoantibody which is directed against anti-histidyl-tRNA synthetase. It can be found in 15-30% patients with myositis and has a higher prevalence in polymyositis (2). The presence of anti Jo-1 antibodies has also been described in overlap syndromes with dermato- or polymyositis and SLE, rheumatoid arthritis or systemic sclerosis (3). However, our case is a rare inpatient presentation of SLE with atypical symptoms associated with positive anti Jo-1 antibodies.
Conclusions: SLE is a complex autoimmune condition with wide variability in presentation and involvement of organ systems. In such cases, it remains imperative to work with a list of diverse differential diagnosis. Rheumatologic consultation may be obtained if necessary. Presence of anti Jo-1 antibody in SLE, as opposed to overlap syndrome, is a unique phenomenon and further studies are needed to understand its prevalence and significance in the disease.