A 56-year-old male had a prior history of pneumoconiosis and an occupation history of precious metal processing for the previous 30 years. The patient had received Special Examinations for Pneumoconiosis in 2005. Pneumoconiosis was compensated by the Ministry of Employment and Labor and the Korea Workers’ Compensation and Welfare Service (COMWEL); however, the official complication for pneumoconiosis was not reported. A chest radiograph showed calcified pneumoconiotic nodules and bilateral nodular type q/q opacities and profusions of 3/3 in both lung fields, and was consistent with the diagnosis of pneumoconiosis in accordance with the International Labour Office (ILO) classification [3]. The patient had a 30 pack-year history of smoking and had been treated for hypertension with nifedipine (120 mg).
The patient presented with a non-specific headache lasting for several days to the outpatient clinic of the Department of Occupational and Environmental Medicine. Blood urea nitrogen (BUN) and serum creatinine levels were 52.5 mg/dl and 4.69 mg/dl, respectively, and were elevated compared with previous values of 20.4 mg/dl for BUN and 1.16 mg/dl for serum creatinine. Microscopic hematuria was detected on urinalysis. The patient was referred to a nephrologist and a kidney sonogram was performed. Renal parenchymal disease affecting both kidneys and a left simple renal cyst of 1.2 cm in size were detected. A kidney biopsy was recommended by the nephrologist but was not undertaken due to the high medical cost.
Approximately 2 weeks following the last visit at the outpatient clinic, the patient was admitted to emergency complaining of aggravated dyspnea and massive hemoptysis. There was no history of fever, joint pain, or skin rashes.
Vital signs revealed an elevated systolic blood pressure of 230 mmHg, increased diastolic blood pressure of 160 mmHg, and a respiratory rate of 30–36 breaths per min. Initially, percutaneous oxygen saturation checked by a rescue worker was 44 %. Auscultation revealed coarse breathing sounds without wheezing throughout both lung fields. Analysis of arterial blood gases on room air showed a pH of 7.179, a PaCO2 of 36.0 mmHg, a PaO2 of 82.0 mmHg, a HCO3 of 12.9 mmol/l, and an O2 saturation of 92.9 %.
Laboratory findings revealed normocytic-normochromic anemia. The erythrocyte sedimentation rate (ESR) was found to be increased at 58 mm/h. Serum levels of high-sensitivity C-reactive protein (hs-CRP) and potassium were elevated (3.32 mg/dl and 7.2 mEq/l, respectively). A BUN level of 101 mg/dl and a serum creatinine level of 10.63 mg/dl were found. The Modification of Diet in Renal Disease estimated glomerular filtration rate (MDRD estimated GFR) was calculated to be 5.07 ml/min/1.73 m2 indicating acute kidney injury. Normal serum protein levels were detected. A routine urinalysis revealed a glucose level of 1+, more than 100 red blood cells per high power field, and proteinuria (3+).
An initial chest radiograph revealed newly developed haziness in both lungs suggesting pneumonia, pulmonary edema, or hemorrhage (Fig. 1b). Underlying pneumoconiosis was observed with little interval change. Non-enhanced abdomen and pelvis computed tomography (CT) showed two potential simple cysts in the left kidney. Low-dose chest CT revealed a newly developed multifocal patchy consolidation in both lungs indicating extensive pneumonia, and a diffuse ground glass opacity suggesting pulmonary edema with or without hemorrhage in both lungs (Fig. 2b).
An ultrasonography guided renal biopsy was performed to investigate the cause of kidney injury and hematuria. Light microscopy revealed a chronic sclerosing glomerulonephritis suggesting ANCA-associated crescentic glomerulonephritis (Fig. 3). Both moderate acute tubular necrosis and arteriosclerosis were also observed. Electron microscopy revealed totally sclerosed glomeruli. P-ANCA was detected using indirect immunofluorescence microscopy in serum (at a titer of 1:80), and in biopsied kidney (Fig. 4).
The patient was received a single course of combination therapy with intravenous cyclophosphamide 11.4 mg/kg/day and prednisolone 2 mg/kg/day for remission induction. In addition, this patient was treated with six plasma exchange sessions for removal of pathological circulating factors, such as ANCAs. After 2 weeks, his p-ANCA titer decreased as 1:20, and 2 weeks later achieved clinical remission and restored general condition. However, he remained on hemodialysis (3 sessions per week). Azathioprine (1.5 mg/kg/day) was described for 3 months as a maintenance therapy and oral prednisolone was tapered off within 2 months after discharge. By 11 months, he maintained remission without immunosuppressant (Fig. 5).