Joint pain, digital necrosis and acute kidney failure in small-vessel autoimmune disease.

Abstract

A 61-year-old female suffered from disseminated joint pain (both hands, elbows, knees, ankles) with a prominent Raynaud phenomenon in both hands for 4 months before admission due to nausea. Acute kidney failure of unknown origin was diagnosed and acral cyanosis of fingers II–IV of the left hand with beginning finger tip necrosis became obvious. To relieve pain and improve ischaemia, she received acetylsalicylic acid and non-steroidal anti-inflammatory drugs. She had no past medical history except for a rapid weight loss (∼10 kg within the previous 3 months) and a smoking history of <40 pack years. On examination, painful acral cyanosis was revealed in all extremities with no destruction of joints or clinically apparent macroangiopathy; however, angiography indicated reduced blood flow in fingers I–III, V of the right hand and no blood flow in fingers I–IV of the left. The estimated glomerular filtration rate (eGFR) was reduced to 7 mL/min; further laboratory testing showed accompanying metabolic acidosis, hyperkalaemia, secondary hyperparathyroidism and iron deficiency anaemia. Autoantibody testing revealed positive cANCA (1280; ref. range <5) and PR-3 ANCA antibody titres (1587 U/mL; ref. range <10 U/mL). Cryoglobulins, rheumatoid factor, complements C3, C4 and CH50 as well as antistreptolysin titres were within the normal ranges and serology for chlamydia, borreliosis and viral hepatitis infections were negative. A diagnosis of focal segmental, necrotizing ANCA-positive glomerulonephritis with focal segmental glomerulosclerosis, advanced acute tubular damage and interstitial nephritis was made following a kidney biopsy. Immunosuppressive therapy was initiated with high-dose prednisolone pulses, followed by oral prednisolone treatment (1 mg/kg body weight daily); cyclophosphamide i.v. fortnightly (initial 10 mg/kg, then 12.5 mg/kg body weight) [1]. Furthermore vasodilatator amlodipine and i.v. prostavasine infusions were applied to improve rheology. Kidney function improved considerably within weeks (eGFR: 32 mL/min); however, severe necrosis of the left hand remained. Cotton gloves and wool bandages were applied to shield fingers (Figures 1–3) until auto-amputation took place (Figure 4). Fig. 2. Left hand after 1 week. Fig. 1. Left hand at admission. Fig. 3. Left hand after 2 weeks. Fig. 4. Left hand after 18 months. ANCA-associated necrotizing granulomatosis is a leukocytoclastic vasculitis of predominantly small vessels with necrosis and granulomatous tissue formation [2]. Every organ may be affected, with preponderance of lungs, kidneys, gastrointestinal tract and mucosal membranes. Categorizations of systemic vasculitides adhere to vessel sizes; however, clinical presentations may not be confined to small arteries/capillaries/venules [3]. Differential diagnoses of secondary Raynaud's phenomena include scleroderma, progressive chronic polyarthritis, systemic lupus erythematodes, arteriosclerosis obliterans and thrombangitis obliterans, which were all refuted by work-up of the case. Raynaud's phenomenon resulting in necrosis of the fingers/toes is not commonly described for ANCA-positive autoimmune diseases, given the involvement of medium-sized vessels. A literature search reveals similar case reports, some of which may belong to overlap syndromes with vasculitis and autoimmune post-infectious phenomena [4]. In the index case, affection of all limbs makes an underlying immunological pathomechanism likely. In conclusion, we believe that Raynaud's phenomenon and digital necrosis should include the differential diagnosis of ANCA-associated necrotizing vasculitis.