Clinical differences among patients with myeloperoxidase-antineutrophil cytoplasmic antibody-positive interstitial lung disease.

INTRODUCTION: Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and idiopathic interstitial lung diseases (IIPs) are positive for myeloperoxidase (MPO)-ANCA. MPO-ANCA-positive vasculitis mainly comprises microscopic polyangiitis (MPA) and unclassifiable vasculitis. These diseases are frequently complicated by interstitial lung disease (ILD). Few studies have reported the clinical differences between the subtypes of MPO-ANCA-positive ILD. Therefore, this study aimed to examine the clinical findings and courses of MPO-ANCA-positive ILD. METHOD: This retrospective study enrolled 100 patients with MPO-ANCA-positive ILD who were categorized into three groups: MPA (n = 44), unclassifiable vasculitis (n = 29), and IIP (n = 27). Our study compared the clinical findings and prognosis of these patients and analyzed the poor prognostic factors. Furthermore, we assessed the association between the patients with and without acute exacerbation of ILD (AE-ILD). RESULTS: Our study found clinical differences in serum markers, clinical symptoms, and treatment regimens among the three groups. ILD complications, as the main cause of death, differed among the three groups (P = 0.04). Patients with unclassifiable vasculitis showed higher survival rates than those with IIP (P = 0.046). Patients with AE-ILD showed fewer general symptoms (P = 0.02) and lower survival rates (P < 0.01) than those without AE-ILD. In multivariate analysis, AE-ILD development was a strong poor prognostic factor for MPO-ANCA-positive ILD. CONCLUSIONS: The subtypes of MPO-ANCA-positive ILD have different clinical features and prognoses. Patients who develop AE-ILD require careful evaluation of clinical courses. Key Points • In myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-positive interstitial lung disease (ILD), patients with unclassifiable vasculitis showed a better prognosis than those with idiopathic ILD.. • Development of acute exacerbation in ILD was a strong poor prognostic factor in patients with MPO-ANCA-positive ILD..

Interstitial lung disease with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis in elderly patients.

Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65 years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65-74 years, n = 29; 75-79 years, n = 18; over 80 years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan-Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.

Nephrotic syndrome caused by immune-mediated acquired LCAT deficiency.

Lecithin-cholesterol acyltransferase (LCAT) is an enzyme involved in maintaining cholesterol homeostasis. In familial LCAT deficiency (FLD), abnormal lipid deposition causes renal injury and nephrotic syndrome, frequently progressing to ESRD. Here, we describe a 63-year-old Japanese woman with no family history of renal disease who presented with nephrotic syndrome. The laboratory data revealed an extremely low level of serum HDL and undetectable serum LCAT activity. Renal biopsy showed glomerular lipid deposition with prominent accumulation of foam cells, similar to the histologic findings of FLD. In addition, she had subepithelial electron-dense deposits compatible with membranous nephropathy, which are not typical of FLD. A mixing test and coimmunoprecipitation study demonstrated the presence of an inhibitory anti-LCAT antibody in the patient's serum. Immunohistochemistry and immunofluorescence detected LCAT along parts of the glomerular capillary walls, suggesting that LCAT was an antigen responsible for the membranous nephropathy. Treatment with steroids resulted in complete remission of the nephrotic syndrome, normalization of serum LCAT activity and HDL level, and disappearance of foam cell accumulation in renal tissue. In summary, inhibitory anti-LCAT antibody can lead to glomerular lesions similar to those observed in FLD.

[Pneumocystis pneumonia developed in two patients with rheumatoid arthritis during treatment of adalimumab].

While tumor necrosis factor (TNF) inhibitors have dramatically improved the clinical outcomes of rheumatoid arthritis (RA) in recent years, infectious complications are a serious concern. Adalimumab (ADA) is a newly-developed human monoclonal antibody against TNF-alpha. Here we report 2 cases of pneumocystis pneumonia (PCP) which developed in RA patients during ADA therapy. One patient is a 66-year-old woman who had a history of RA for 6 months. The patient was given ADA at 40 mg biweekly for her active arthritis which had been refractory to 6 mg/week of methotrexate (MTX), and 5 mg/day of prednisolone (PSL). One hundred and six days later, she was admitted to our hospital because of fever, cough, and dyspnea. Another patient is a 62-year-old man who had a history of RA for 3 years. Since his arthritis was so active even under the treatment with MTX (8 mg/week) and PSL (15 mg/day), the patient started to be given ADA at 40 mg biweekly. After 28 days, the patient was admitted to the hospital because of dyspnea. Chest roentgenogram and computed tomography revealed interstitial pneumonia in both patients. Beta-D-glucan levels were so high in their serum suggesting the diagnosis of PCP, which was confirmed by the detection of Pneumocystis jirovecii DNA in the sputa by polymerase chain reaction. The patients were immediately treated with sulfamethoxazole/trimethoprim and high-dose prednisolone, which successfully improved pneumonia, and they were discharged from the hospital on the 8(th) and 16(th) day, respectively. PCR and ß-D-glucan were useful for the early diagnosis of PCP and lead to the timely induction of adequate treatment and the rescue of these patients.