Page 30 - Delaware Medical Journal - March/April 2020

Table 2: Serology marker difference between drug induced vasculitis, ANCA-associated vasculitis, and idiopathic systemic lupus
Drug-induced vasculitis
SLE
AAV
Antihistone antibodies
Can be seen
Rare
Absent
AntidsDNA antibodies
Absent
Common
Absent
ANCA
Common
Rare
Common
Antiphospholipid antibodies
Common
Common
Rare
Immune complexes
Rare
Common
Absent
due to concern for hydralazine-
induced vasculitis. Subsequent renal biopsy with light microscopy revealed focal segmental necrotizing and crescentic glomerulonephritis, and
antigen antibody immune complexes. Hydralazine was discontinued at admission. At discharge, the patient’s renal biopsy results were pending and
he was discharged on Prednisone 60 mg daily. Patient had close follow-up with nephrology, where he was started on rituximab with initial improvement in his renal function with creatinine for 2.59 mmol/L. Prior to rituximab initiation, he had negative tuberculosis testing, negative blood cultures, and unremarkable liver function tests. Unfortunately, in the week following initiation of therapy, he suffered a gastrointestinal bleed and cardiac arrest at home. He was resuscitated, brought to the intensive care unit in profound shock thought to be hemorrhagic and septic in etiology, and expired. Autopsy was not pursued, so it is uncertain whether there could have been pulmonary hemorrhage.
DISCUSSION
Drug-induced vasculitis is associated with commonly used drugs like hydralazine, propylthiouracil, minocycline, phenytoin, penicillamine, allopurinol, and sulfasalazine. However, this syndrome only develops in a minority of patients.3 Table 1 summarizes medications associated with drug-induced vasculitis. induced ANCA-associated vasculitis (AAV) often results in renal, pulmonary, and cutaneous disease.5
This patient appeared to have isolated renal disease, without pulmonary or cutaneous manifestations. Hydralazine- induced ANCA-associated vasculitis is strongly associated with positive MPO antibodies,6 and often results in poor renal outcomes.7
Abbreviations: SLE = systemic lupus erythematosus, AAV = anti-neutrophil cytoplasmic antibody-associated vasculitis
Other associated antibodies include ANA, anti-histone antibody, anti-elastase antibody, and anti-phospholipid antibody. Our patient was positive for PR3 ANCA, which isn’t commonly reported; MPO ANCA; ANA; and anti-histone antibody. The anti-
histone antibody is commonly seen with drug-induced vasculitis and absent with ANCA-associated vasculitis.4 The serologic markers can help differentiate drug-induced vasculitis from idiopathic systemic lupus and ANCA-associated vasculitis, as summarized in Table 2.8
A high degree of suspicion is needed when patients present with symptoms of vasculitis when on hydralazine, in order to aid in prompt diagnosis and treatment, and prevent progression to irreversible disease. Diagnosis is supported by regression of vasculitis symptoms upon withdrawal of offending diagnosis.
Optimal management of this condition has yet to be determined. Mainstays of treatment offending agent with avoidance in the future, high-dose glucocorticoids, and timely initiation of cyclophosphamide or rituximab in those with severe organ involvement.9 Duration of immunosuppressive therapy
is inconclusive, but should be shorter than primary ANCA-associated vasculitis and long-term therapy may not be necessary.
CONCLUSION
The key learning point of the discussion above is that when encountering patients with a rise in serum creatinine or urinalysis thorough medication reconciliation should be done, with common vasculitis-inducing medications in mind. Once the potential
of treatment is prompt removal of the offending agent, high-dose glucocorticoids, and initiation of immunosuppressive therapy in those with severe organ involvement.
CONTRIBUTORS
■ MICHAEL GOULET, DO is a graduate of Philadelphia College of Osteopathic Medicine. He is an internal medicine PGY3 and rising chief resident at ChristianaCare in Newark, Delaware.
■ CATHERINE TESKIN, DO is a second-year internal medicine resident at ChristianaCare. She has a special interest in rheumatology and is interested in pursuing a rheumatology fellowship.
■ AJEETPAL HANS, MD is an Associate Program Director for Internal Medicine Program at ChristianaCare. He is board certified in internal medicine and has practiced as a teaching hospitalist since 2011. He is the lead physician of Education Pillar of Division of Hospital Medicine at ChristianaCare.
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Del Med J | March/April 2020 | Vol. 92 | No. 2