Clinical usefulness of serum angiotensin converting enzyme in silicosis

INTRODUCTION

Silicosis is an irreversible and incurable disease. Preventive measures to eliminate exposure are the only effective way to reduce morbidity and mortality. In such situations, having a biomarker for early diagnosis or to predict evolution would be very useful in order to improve control of the disease. The elevation of serum angiotensin-converting enzyme (sACE) in silicosis has been described in previous studies, although its relationship with severity and prognosis is not clear.

AIMS

To determine the levels of sACE in a cohort of patients with exposure to silica dust with and without silicosis, and to assess their impact on the prognosis of the aforementioned patients.

METHOD

Prospective observational study on patients treated in a silicosis clinic from 2009 to 2018. sACE levels and pulmonary function tests were performed. Radiological progression was assessed in patients who had already had 2 X-rays of the thorax and / or two CT scans with at least a 1-year interval, from the time of inclusion in the study.

RESULTS

A total of 413 cases of silicosis were confirmed, as well as 73 with exposure to silica dust but without silicosis. The mean sACE level for healthy subjects was 27.5±7.3U/L, for exposed patients without silicosis it was 49.6±24.2U/L, for simple silicosis it was 57.8±31,3U/L and for complicated silicosis it was 74.5±38.6U/L. Patients with a higher sACE generally progressed radiologically during follow-up (73.3±38.0 vs. 60.4±33.7; p<.001) and so the category of silicosis changed (73,9±38.1 vs. 62.5±34.6; p<.021).

CONCLUSIONS

sACE was elevated in patients with silicosis, and the greater its severity, the higher it was, which is associated with disease progression measured radiologically or as a category change of silicosis.

Clinical Significance of Delirium With Catatonic Signs in Patients With Neurological Disorders

OBJECTIVE

According to DSM-5, catatonia and delirium are mutually exclusive clinical syndromes. The investigators explored the co-occurrence of delirium and catatonia (i.e., catatonic delirium) and the clinical significance of this syndrome with a sample of neurological patients.

METHODS

This prospective study with consecutive sampling included patients diagnosed with delirium at the National Institute of Neurology and Neurosurgery of Mexico. DSM-5 criteria for delirium, the Confusion Assessment Method, and the Delirium Rating Scale-Revised-98 were used to select and characterize patients. Catatonia was assessed using the Bush-Francis Catatonia Rating Scale and DSM-5 diagnostic criteria. Logistic regression analysis was performed to identify etiological factors associated with catatonic delirium.

RESULTS

A total of 264 patients with delirium were included, 61 (23%) of whom fulfilled the criteria for catatonia and delirium simultaneously. Brain tumors, subarachnoid hemorrhage, acute hydrocephalus, and ischemic stroke were associated with delirium without catatonic signs. Catatonic delirium was observed among patients with encephalitis, epilepsy, brain neoplasms, and brain tuberculosis. After multivariate analysis, the association between catatonic delirium and encephalitis (both viral and anti-N-methyl-d-aspartate receptor [NMDAR]) was confirmed.

CONCLUSIONS

Delirium is a common complication of neurological diseases, and it can coexist with catatonia. The recognition of catatonic delirium has clinical significance in terms of etiology, as it was significantly associated with viral and anti-NMDAR encephalitis.