CASE PRESENTATION
The patient was an 80-year-old Japanese man. During the month before
admission, he experienced progressive dysphagia and muscle weakness in
the lower extremities. Because of difficulty with walking, he sought
medical attention at the hospital. He had a 60-year history of smoking
10 cigarettes per day and infrequent hospital visits and was not
currently on any medication. The patient had no history of Raynaud
phenomenon.
On admission, the patient’s temperature was 37.3°C, and no other
abnormalities were detected in his vital signs. Indurated edema was
observed in both lower legs, and a purple color change was observed in
the second to fifth fingers of the left hand (Fig. 1–A). Although
muscle atrophy was not evident because of edematous changes, the patient
experienced generalized muscle pain in the bilateral thighs. The
strength in the upper extremities was assessed as a
Muscle Strength Testing (MMT)
score of 4, while the iliopsoas and quadriceps muscles were graded as an
MMT score of 2.
Blood test findings revealed elevated levels of muscle enzymes (creatine
kinase [CK], 7,930 U/L and C-reactive protein [CRP], 2.0 mg/dL),
an erythrocyte sedimentation rate (ESR) of 16 mm/h, and an elevated
inflammatory response. Results were negative for antinuclear antibodies,
rheumatoid factor (RF), myeloperoxidase-anti-neutrophil cytoplasmic
antibodies (MPO-ANCA), proteinase-3-anti-neutrophil cytoplasmic
antibodies (PR3-ANCA), anti-Scl-70, U1RNP, centromere, Jo-1, PL-12,
anti-melanoma differentiation-associated gene-5 (MDA5), and
anti-transcriptional intermediary factor 1-γ (TIF1-γ), and for MI-2, Ku,
PM-SCL75, PM-SCL100, SRP, PL-7, EJ, and OJ. However, Ro-52 (EUROLINE
Myositis Profile 3; EUROIMMUN Medizinische Labordiagnostika AG, Lubeck,
Germany) demonstrated a strong positive result (3+). During the
patient’s hospitalization, further testing using immunoprecipitation was
conducted at another institute’s laboratory, and the patient was
strongly positive for anti-OJ antibodies.
Contrast-enhanced magnetic resonance imaging (MRI) revealed a contrast
effect in muscle electromyography, and positron emission
tomography-computed tomography also showed extensive soft tissue
accumulation despite normal blood glucose levels (Fig. 2A and B). Muscle
biopsy findings were consistent with myositis, which led to a diagnosis
of anti-ARS antibody syndrome. Chest CT upon admission indicated chronic
obstructive pulmonary disease and mild interstitial pneumonia; however,
no malignancy was detected. MRI of the head showed no abnormality.
After admission, the color of the patient’s fingers changed from purple
to black, indicating necrosis (Fig. 1B). Contrast-enhanced CT images
showed no signs of vascular stenosis or obstruction. Intravenous heparin
sodium (10,000 U/day), prostaglandins (limaprost alfadex 30 μg/day),
tocopherol nicotinate 600 mg/day, and warming agents for a week, the
progression of the finger necrosis did not stop.
On day 10 of hospitalization, the patient’s respiratory status
deteriorated, necessitating ventilator management. Worsening
interstitial pneumonia was treated with a methylprednisolone pulse of
1,000 mg for 3 days and post-therapy
prednisolone (PSL; 60 mg [1
g/kg]). Following initiation of treatment, his respiratory condition
rapidly improved, and he was weaned off the ventilator within
approximately 10 days. Close examination revealed no exacerbation of
interstitial pneumonia or changes in Krebs von den Lungen 6 (KL-6; 216
U/mL) or surfactant protein-D (SP-D; 65 ng/mL). This was attributed to
improved carbon dioxide (CO2) narcosis. After the first
day of PSL pulse administration, a purple transition zone appeared in
the necrotic area of the fingers, which subsequently ceased expanding
(Fig. 1C).
The patient experienced repeated episodes of aspiration pneumonia owing
to dysphagia; however, over time, both swallowing ability and lower limb
muscle strength gradually improved. On day 40 of hospitalization, the
MMT score of the lower limbs recovered to 3–4, and CK levels were
normal. Additionally, the CRP level and ESR had substantially decreased.
Furthermore, the progression of finger necrosis had ceased. By day 70 of
hospitalization, all MMT scores had improved to 5, indicating complete
recovery of muscle strength. Swallowing function had also improved to
the state before the disease onset, leading to the patient’s discharge
from the hospital. Although the necrotic areas of the fingers became
narrower and drier after pulse therapy, necrosis did not progress (Fig.
1D).