Aphy on a superpose 6 column was used as described in previous studies [6,7]. This method separates SP-A molecules with regard to their oligomerization form. The column was calibrated by using blue dextran (2000 kDa), holotransferrin (669 kDa) and bovine serum albumin (66 kDa)(not shown). Samples of 1 ml of BAL fluid and 500 ml of serum were loaded. The SP-A content of the eluted fractions (800 ml) was determined by Slot-Blot assay. The void volume of the column eluting between fractions 8 and 9 was about 6.8 ml. SP-A usually elutes as three distinct peaks, ranging from fractions 9?2, 13?7 and 18?2 (Fig. 1). The first peak contains the largest SP-A multimers, i.e. 18 mers and bigger, the second peak 6 to 12 mers and the third Table 1. Clinical data of the subjects investigated.peak di- and trimers. A major peak was defined to be present if the SP-A Peptide M site amount was at least or more than 20 of the total SP-A eluted from the column and each peak was separated from the previous by a distance of 5 fractions of 0.8 ml each. The cut off of 20 was arbitrarily selected after visual inspection of all chromatograms normalized into a grid. There were baseline fluctuations and drifts up to 10 and the level of 20 of total SPA was selected to define the presence or absence of a peak in the preset elution fractions. There were a total of 140 chromatograms which had a potential for 177 changes in pattern (i.e. 010 can improve or deteriorate, etc). Lowering the threshold to 10 , would introduce 15 changes in the category of the pattern in both directions and a net change of 5 improvements. The threshold set also makes sure that a peak is represented by a sufficient amount of the total SP-A. Depending on the presence (1) or absence (0) of any of the three major peaks in a sample (Fig. 1), generally 7 different patterns of SP-A can be classified (“Code” in first column of Table 2). The inter-run reproducibility of the separation of SP-A by the gel chromatography and determination of SP-A concentration by slotblot was assessed in four serum and 2 BAL samples of 5 different individuals by repeated analysis at intervals of four weeks. The reproducibility of the gel chromatography was excellent comparing the curve forms, the coefficient of variation for SP-A content assessed by the area under the curve of the peaks was 29 . SP-A present in each of the fractions from gel chromatography was determined by slot blot (see below) and the amounts of the different structures were calculated from the area under the curve of the corresponding peak as a percentage of total amounts of SPA present (Fig. 1).Subjects’ characteristics Age (years) Gender in female (absolute numbers)) Body mass index in overweight/normal/underweight (absolute numbers)1 FEV1 ( pred.)11 Mean change of FEV1 per year (DFEV1)( pred.)111 Lung disease group in mild/moderate/severe (absolute numbers) P.aer. infection of the lung at sampling point ( ) IgG in serum (ratio to upper normal value) Neutrophils in BAL ( ) SP-A level in BAL (ng/ml)1111 SP-A level in serum (ng/ml)1111 Agglutinate size in BAL (Pixel) (18mers/6mers/trimers) Agglutinate size in serum (Pixel) (18mers/6mers/trimers)Cystic purchase 94-09-7 fibrosis 1366 (n = 46) 57 (26) 20/47/33 (7/22/15) 94626 (n = 46) ?610 (n = 42) 72/0/28 (28/0/11) 24 (n = 11) 0.961.8 (n = 28) 28622 (n = 39)** 502363314 (n = 39) 2669 (n = 37) 316630/234615/74615 (n = 10) 481635/380632/146613 (n = 10)Chronic bronchitis 11612 ( n = 25) 52 (13) 17/83/0 (2/10/0) 94622 (n = 8.Aphy on a superpose 6 column was used as described in previous studies [6,7]. This method separates SP-A molecules with regard to their oligomerization form. The column was calibrated by using blue dextran (2000 kDa), holotransferrin (669 kDa) and bovine serum albumin (66 kDa)(not shown). Samples of 1 ml of BAL fluid and 500 ml of serum were loaded. The SP-A content of the eluted fractions (800 ml) was determined by Slot-Blot assay. The void volume of the column eluting between fractions 8 and 9 was about 6.8 ml. SP-A usually elutes as three distinct peaks, ranging from fractions 9?2, 13?7 and 18?2 (Fig. 1). The first peak contains the largest SP-A multimers, i.e. 18 mers and bigger, the second peak 6 to 12 mers and the third Table 1. Clinical data of the subjects investigated.peak di- and trimers. A major peak was defined to be present if the SP-A amount was at least or more than 20 of the total SP-A eluted from the column and each peak was separated from the previous by a distance of 5 fractions of 0.8 ml each. The cut off of 20 was arbitrarily selected after visual inspection of all chromatograms normalized into a grid. There were baseline fluctuations and drifts up to 10 and the level of 20 of total SPA was selected to define the presence or absence of a peak in the preset elution fractions. There were a total of 140 chromatograms which had a potential for 177 changes in pattern (i.e. 010 can improve or deteriorate, etc). Lowering the threshold to 10 , would introduce 15 changes in the category of the pattern in both directions and a net change of 5 improvements. The threshold set also makes sure that a peak is represented by a sufficient amount of the total SP-A. Depending on the presence (1) or absence (0) of any of the three major peaks in a sample (Fig. 1), generally 7 different patterns of SP-A can be classified (“Code” in first column of Table 2). The inter-run reproducibility of the separation of SP-A by the gel chromatography and determination of SP-A concentration by slotblot was assessed in four serum and 2 BAL samples of 5 different individuals by repeated analysis at intervals of four weeks. The reproducibility of the gel chromatography was excellent comparing the curve forms, the coefficient of variation for SP-A content assessed by the area under the curve of the peaks was 29 . SP-A present in each of the fractions from gel chromatography was determined by slot blot (see below) and the amounts of the different structures were calculated from the area under the curve of the corresponding peak as a percentage of total amounts of SPA present (Fig. 1).Subjects’ characteristics Age (years) Gender in female (absolute numbers)) Body mass index in overweight/normal/underweight (absolute numbers)1 FEV1 ( pred.)11 Mean change of FEV1 per year (DFEV1)( pred.)111 Lung disease group in mild/moderate/severe (absolute numbers) P.aer. infection of the lung at sampling point ( ) IgG in serum (ratio to upper normal value) Neutrophils in BAL ( ) SP-A level in BAL (ng/ml)1111 SP-A level in serum (ng/ml)1111 Agglutinate size in BAL (Pixel) (18mers/6mers/trimers) Agglutinate size in serum (Pixel) (18mers/6mers/trimers)Cystic fibrosis 1366 (n = 46) 57 (26) 20/47/33 (7/22/15) 94626 (n = 46) ?610 (n = 42) 72/0/28 (28/0/11) 24 (n = 11) 0.961.8 (n = 28) 28622 (n = 39)** 502363314 (n = 39) 2669 (n = 37) 316630/234615/74615 (n = 10) 481635/380632/146613 (n = 10)Chronic bronchitis 11612 ( n = 25) 52 (13) 17/83/0 (2/10/0) 94622 (n = 8.
