Cigarette smoking and other inhaled toxins in anti-GBM disease

Clinical significance of cigarette smoking and dust exposure in pulmonary alveolar proteinosis: a Korean national survey

BACKGROUND

This study aimed to investigate clinical characteristics of Korean PAP patients and to examine the potential risk factors of PAP.

METHODS

We retrospectively reviewed medical records of 78 Korean PAP patients diagnosed between 1993 and 2014. Patients were classified into two groups according to the presence/absence of treatment (lavage). Clinical and laboratory features were compared between the two groups.

RESULTS

Of the total 78 PAP patients, 60% were male and median age at diagnosis was 47.5 years. Fifty three percent were ever smokers (median 22 pack-years) and 48% had a history of dust exposure (metal 26.5%, stone or sand 20.6%, chemical or paint 17.7%, farming dust 14.7%, diesel 14.7%, textile 2.9%, and wood 2.9%). A history of cigarette smoking or dust exposure was present in 70.5% of the total PAP patients, with 23% having both of them. Patients who underwent lavage (n = 38) presented symptoms more frequently (38/38 [100%] vs. 24/40 [60%], P < 0.001) and had significantly lower PaO₂ and DL_CO with higher D(A-a)O₂ at the onset of disease than those without lavage (n = 40) (P = 0.006, P < 0.001, and P = 0.036, respectively). Correspondingly, the distribution of disease severity score (DSS) differed significantly between the two groups (P = 0.001). Based on these, when the total patients were categorized according to DSS (low DSS [DSS 1-2] vs. high DSS [DSS 3-5]), smoking status differed significantly between the two groups with the proportion of current smokers significantly higher in the high DSS group (11/22 [50%] vs. 7/39 [17.9%], P = 0.008). Furthermore, current smokers had meaningfully higher DSS and serum CEA levels than non-current smokers (P = 0.011 and P = 0.031), whereas no difference was found between smokers and non-smokers. Regarding type of exposed dust, farming dust was significantly associated with more severe form of PAP (P = 0.004).

CONCLUSION

A considerable proportion of PAP patients had a history of cigarette smoking and/or dust exposure, suggestive of their possible roles in the development of PAP. Active cigarette smoking at the onset of PAP is associated with the severity of PAP.

Crescentic Glomerulonephritis with Anti-GBM and p-ANCA Antibodies

We are presenting a case of renal failure with anti-GBM and p-ANCA antibodies positive. Patients with dual antibodies are considered to be a vasculitis-variant of anti-GBM antibody nephritis. These patients may have atypical presentation and it may delay diagnosis and treatment. Recurrence rate is higher in these patients. We reviewed the literature of cases and studies on cresenteric glomerulonephritis with anti-GBM and p-ANCA positive patients. We recommend that patients suspected with pulmonary-renal syndrome should be checked for anti-GBM and p-ANCA antibodies, should undergo renal biopsy and should should have close long term follow up to watch for recurrence.

Anti-GBM disease and renal vein thrombosis

A 23-year-old female who presented with advanced renal failure was subsequently diagnosed with renal vein thrombosis and antiglomerular basement membrane (GBM) antibody disease. A previous case of renal vein thrombosis has been reported in association with anti-GBM disease, but to our knowledge, this is the first reported case in which the presentation of anti-GBM disease and renal vein thrombosis was concurrent. Further study is essential to understand if the association of anti-GBM disease and renal vein thrombosis as seen in our case was pure coincidence or is in fact occurs more frequently. It may be that the dual diagnosis is not made as establishing one sufficient diagnosis for renal failure may halt further investigations for additional diagnoses.

Evolution of antiglomerular basement membrane glomerulonephritis into membranous glomerulonephritis

Antiglomerular basement membrane glomerulonephritis (anti-GBM GN) is a rare disease characterized by autoantibodies to the alpha 3 chain of type IV collagen in the GBM. It is also known as Goodpasture's syndrome when associated with pulmonary hemorrhage due to autoantibodies to the alpha 3 chain of type IV collagen also present in pulmonary alveoli. Even more rare is the evolution of anti-GBM GN into membranous nephropathy (MN). We report the management of a 9-year-old Caucasian girl with anti-GBM GN that evolved into MN and briefly review the literature.

Pulmonary alveolar proteinosis: progress in the first 44 years

Pulmonary alveolar proteinosis is a rare clinical syndrome that was first described in 1958. Subsequently, over 240 case reports and small series have described at least 410 cases in the literature. Characterized by the alveolar accumulation of surfactant components with minimal interstitial inflammation or fibrosis, pulmonary alveolar proteinosis has a variable clinical course ranging from spontaneous resolution to death with pneumonia or respiratory failure. The most effective proven treatment--whole lung lavage--was described soon after the first recognition of this disease. In the last 8 years, there has been rapid progress toward elucidation of the molecular mechanisms underlying both the congenital and acquired forms of pulmonary alveolar proteinosis, following serendipitous discoveries in gene-targeted mice lacking granulocyte-macrophage colony-stimulating factor (GM-CSF). Impairment of surfactant clearance by alveolar macrophages as a result of inhibition of the action of GM-CSF by blocking autoantibodies may underlie many acquired cases, whereas congenital disease is most commonly attributable to mutations in surfactant protein genes but may also be caused by GM-CSF receptor defects. Therapy with GM-CSF has shown promise in approximately half of those acquired cases treated, but it is unsuccessful in congenital forms of the disease, consistent with the known differences in disease pathogenesis.

Cigarette smoking: an important renal risk factor - far beyond carcinogenesis

In recent years, it has become apparent that smoking has a negative impact on renal function, being one of the most important remediable renal risk factors. It has been clearly shown that the risk for high-normal urinary albumin excretion and microalbuminuria is increased in smoking compared to non-smoking subjects of the general population. Data from the Multiple Risk Factor Intervention Trial (MRFIT) indicate that at least in males, smoking increases the risk to reach end-stage renal failure. Smoking is particularly "nephrotoxic" in older subjects, subjects with essential hypertension and patients with preexisting renal disease. Of interest, the magnitude of the adverse renal effect of smoking seems to be independent of the underlying renal disease. Death-censored renal graft survival is decreased in smokers, indicating that smoking also damages the renal transplant. Cessation of smoking has been show to reduce the rate of progression of renal failure both in patients with renal disease or a renal transplant. The mechanisms of smoking-induced renal damage are only partly understood and comprise acute hemodynamic (e.g., increase in blood pressure and presumably intraglomerular pressure) and chronic effects (e.g., endothelial cell dysfunction). Renal failure per se leads to an increased cardiovascular risk. The latter is further aggravated by smoking. Particularly survival of smokers with diabetes mellitus on hemodialysis is abysmal. In the present review article the current state of knowledge about the renal risks of smoking is reviewed. It is the aim of the article to point out that smoking not only increases the risk of renal cell carcinoma or uroepithelial cell carcinoma, but also the risk of a faster decline of renal function. The latter is a relatively new negative aspect which has not been widely recognized.