[An unusual cause of cystic lung disease: light chain deposition disease]

Characteristics of primary Sjögren's syndrome related lymphocytic interstitial pneumonia

Objective

This paper is aimed at investigating the clinical characteristics of primary Sjogren’s syndrome (pSS) with lymphocytic interstitial pneumonia (LIP).

Methods

The demographic data, clinical manifestations, laboratory and radiological findings, treatment, and prognosis from 15 cases of pSS-LIP patients were retrospectively analyzed. The data were compared with t test, χ² test, and Pearson/Spearman correlation analysis.

Results

(1) Fifteen cases of patients with pSS-LIP are all females (100%). Compared with pSS with interstitial lung disease(pSS-ILD) patients, the incidence of dry cough, dental caries is higher in pSS-LIP patients. The incidence of shortness of breath, weight loss, and crackles is lower in pSS-LIP patients than that of pSS-ILD patients. (2) Compared with pSS-ILD patients, pSS-LIP patients had higher percentage of patients with ANA, anti-SSA52KD antibody, anti-SSA60KD antibody, and anti-SSB antibody, and the higher concentration of serum globulin. (3) Compared with pSS-ILD patients, the frequency of obstructive ventilation dysfunction is significantly higher and the frequency of diffusion dysfunction is significantly lower in pSS-LIP patients. (4) The most frequent HRCT findings in patients with pSS-LIP is cysts (100%), followed by ground-glass opacities (73.3%), nodular shadow (73.3%) among the pSS-LIP patients. Compared with PSS-ILD patients, the incidence of pulmonary nodule shadow is significantly higher in PSS-LIP patients, while that of grid shadow was significantly lower. (5) Compared with the baseline, the sum of the number, maximum diameter, and diameter of cysts in three levels of pSS-LIP patients showed an increasing trend after treatment. (6) Correlation analysis: The changes of ground-glass opacities were positively correlated with using GC or not, and those were negatively correlated with the dose of GC treatment. Besides, there is a positive correlation between the annual change rate of the maximum diameter of cysts (△Ømax1/t) and the use of CTX; there is a positive correlation between the annual change rate of the total diameter of cysts (△Øsum1/t) and the use of CTX.

Conclusion

To the patients of pSS-LIP, female were more common than male, and the onset of LIP was usually more insidious. Hyperglobulinemia and anti-SSA antibody were more prominent in patients with pSS-LIP. Pulmonary function showed the higher rate of obstructive ventilation dysfunction and the lower rate of diffusion dysfunction. The appearance of ground-glass opacities in pSS-LIP patients suggests that the infiltration of inflammatory cells increases, which may cause airway compression, the expansion of terminal bronchioles, and the formation of cysts. The more ground-glass opacities appear earlier, and the more appearance of new cysts later. Therapy with glucocorticoid may be effective on the ground-glass opacity during acute stage, and therapy with cyclophosphamide may be effective on the cysts during chronic stage. The heavier ground-glass opacity is at baseline, the more likely it will recur during maintenance treatment. So follow-up closely is needed.

Key Points • It is the first clinical study with more cases of patients with pSS-LIP. • Female and hyperglobulinemia and anti-SSA antibody were more prominent in patients with pSS-LIP. • Pulmonary function showed the higher rate of obstructive ventilation dysfunction and the lower rate of diffusion dysfunction. • Therapy with glucocorticoid may be effective on the ground-glass opacity during acute stage, and therapy with cyclophosphamide may be effective on the cysts during chronic stage.

[Effect of surgery of pulmonary cysts related to immunoglobulin light chain deposits]

INTRODUCTION

Light chain deposition disease is a rare anatomo-clinical disorder, which rarely leads to cystic lung destruction.

CASE REPORT

We report the case of a 62years old female patient with a history of a monoclonal gammopathy of unknown significance who developed progressive dyspnea. Thoracic CT-scan demonstrated a diffuse pulmonary cystic disorder with predominance in the right lower lobe. Thoracoscopic surgical resection of that lobe led to a diagnosis of non-amyloid kappa light chain deposits. Surgery also resulted in a lung volume reduction effect with clinical and functional benefits related to improved ventilation of adjacent segments.

CONCLUSION

This report of pulmonary cystic disorder related to a light chain deposition disease highlights the potential clinical and functional benefits observed after lung volume reduction surgery.

Cystic Lung Diseases: Algorithmic Approach

Cysts are commonly seen on CT scans of the lungs, and diagnosis can be challenging. Clinical and radiographic features combined with a multidisciplinary approach may help differentiate among various disease entities, allowing correct diagnosis. It is important to distinguish cysts from cavities because they each have distinct etiologies and associated clinical disorders. Conditions such as emphysema, and cystic bronchiectasis may also mimic cystic disease. A simplified classification of cysts is proposed. Cysts can occur in greater profusion in the subpleural areas, when they typically represent paraseptal emphysema, bullae, or honeycombing. Cysts that are present in the lung parenchyma but away from subpleural areas may be present without any other abnormalities on high-resolution CT scans. These are further categorized into solitary or multifocal/diffuse cysts. Solitary cysts may be incidentally discovered and may be an age related phenomenon or may be a remnant of prior trauma or infection. Multifocal/diffuse cysts can occur with lymphoid interstitial pneumonia, Birt-Hogg-Dubé syndrome, tracheobronchial papillomatosis, or primary and metastatic cancers. Multifocal/diffuse cysts may be associated with nodules (lymphoid interstitial pneumonia, light-chain deposition disease, amyloidosis, and Langerhans cell histiocytosis) or with ground-glass opacities (Pneumocystis jirovecii pneumonia and desquamative interstitial pneumonia). Using the results of the high-resolution CT scans as a starting point, and incorporating the patient's clinical history, physical examination, and laboratory findings, is likely to narrow the differential diagnosis of cystic lesions considerably.