Serum Markers And Lipid Metabolism In Idiopathic Pulmonary Alveolar Proteinosis

PART ONEBackground:Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by PAS positive lipoproteinaceous material accumulation in the pulmonary alveoli, of which autoimmune or idiopathic type accounts for about90%. Anti-GM-CSF antibody is reported to possess high sensitivity and specificity in the diagnosis of IPAP. We established the quantitative method of testing the antibody in China and analyzed its value in IPAP.Methods:Anti-GM-CSF antibody was purified from an IPAP patient. Measure the concentration using the BCA protein measuring kit after testing purity and activity with SDS-PAGE and Western blot respectively. Then the serum antibody, SP-D and YKL-40levels of30IPAP patients,25healthy volunteers and15patients of other lung diseases were tested by ELISA method. LDH, CEA, artery blood gas test and pulmonary function test results were collected and analyzed. Then the difference between the groups and the relationship between the two of the markers was tested.Results:The level of serum anti-GM-CSF antibody was higher in IPAP patients than in healthy volunteers and disease control patients and did not correlate with serum LDH, CEA, SP-D, YKL-40, P(A-a)O2, SaO2or TLCO%(P>0.05). IPAP patients had higher serum LDH, CEA, SP-D and YKL-40levels. LDH, CEA correlated well with SaO2, TLCO%, P(A-a)O2and serum SP-D level. Patients who needed WLL treatment had higher serum LDH and CEA levels but not anti-GM-CSF antibody, SP-D and YKL-40levels (P>0.05). Besides, SaO2and PaO2were lower and P(A-a)O2was higher in these patients (P>0.05).Conclusion:The sensitivity and specificity of anti-GM-CSF antibody in IPAP diagnosis were both100%, and this test should be recommended in clinical diagnosis of PAP. But the level of this antibody did not correlate with disease severity and could not be used to predict the need for WLL treatment. Serum LDH, CEA and SP-D levels correlated well with disease severity and serum LDH, CEA might be a predictor of the need for WLL treatment.PART TWOBackground:To study the lipid metabolism characters of IPAP patients and to analyze its value in PAP diagnosis and treatment.Method:Serum lipids of62non-diabetic IPAP patients and100healthy volunteers were tested after an overnight fasting. Anti-GM-CSF antibody level of30APAP patients was measured by ELISA method. The correlation of lipids and other markers were analyzed.Results:55of62IPAP patients (88.7%) suffered from impaired lipid metabolism. The TC and LDL-C levels (5.39±1.12mmol/1and3.47±1.01mmol/1respectively) was higher in IPAP patients than in healthy volunteers (5.05±0.97mmol/1)(P<0.05). HDL-C level (1.11[0.97-1.30] mmol/1) was lower in IPAP patients than in healthy volunteers (P<0.05), and negatively correlated with P(A-a)O2. LDH/LDH (3.15±1.08) and TC/HDL (4.81±1.36) were higher in IPAP group. There were no differences in TG level between the two groups (P>0.05). The lipid level except HDL did not correlate with disease severity markers such as LDH, CEA, P(A-a)O2, SaO2or TLCO%(P>0.05). The IPAP patients were divided into two groups according to the need for WLL treatment. There were no differences in lipid metabolism between the two groups.Conclusion:IPAP patients were likely to suffer from impaired serum lipid metabolism. They had higher serum TC, LDL, LDL/HDL and TC/HDL levels, but these markers were not related to disease severity and could not be used as predictors of the need for WLL treatment. HDL-C level was lower in IPAP patients, and negatively correlated with P(A-a)O2but not with other disease severity markers.