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Bronchial gland measurements: A continuing search for a “Yardstick”
EXPERI1fENTAL
ASD
KIOLECULAR
PATHOLOGY
Bronchial A Continuing
18,
219-224
Gland Measurements: Search for a “Yardstick”
CARLOS W. M. BEDROSSIAN, AND Departments
of Pathology Received
July
(1973)
S. DONALD
and Biomathematics, Baylor Houston, Texas 77025 18, 1972;
GREENBERG,
S. DURAN
BENJAMIN
accepted
October
College
of Aletlicine,
2, 1972
Bronchial morphometry has been the object of great interest in the past few years. A recent investigation showed poor correlation between the Reid Index and gland area determinations by a variety of methods. In the present stndy, gland/ wall ratio (Reid Index) was compared with estimation of total, inner, and outer gland areas by the card-weighing method. Correlation was in general poor but unexpectedly presented a lower Coefficient Index for glands located internal than for those located external to the cartilage. A new proposed index of gland/lumen ratio has the advantage of including information not only about the glands in their entirety, but also the crosssectional luminal area of bronchi.
morphology of the bronchi has been the object of several studies in the last few years (Reid, 1960; Restrepo and Heard, 1963a; Restrepo and Heard, 196313;Hale et al., 1968; Dunnill et al., 1969; Macleod and Heard, 1969; Tanden and Alastair, 1969), and various morphometric methods have been applied to assessbronchial wall glands (Reid, 1960; Restrepo and Heard, 1963a; Restrepo and Heard, 1963b), cartilage (Tanden and Alastair, 1969), and smooth muscle (Macleod and Heard, 1969). Among these, the bronchial glands have received the greatest attention, for hypertrophy of these structures is believed to be the hallmark of chronic bronchitis (American Thoracic Society, 1962). A recent comparison of bronchial gland measurements by different techniques revealed the Reid Index to correlate poorly with total gland areas expressed as absolute values (Bedrossian, et al., 1971). In contrast, determination of gland area by such methods as planimetry, point count, and ‘card weighing correlated very well with each other. Planimetry, while the most accurate, proved to be tedious, card weighing showed considerable saving in time without loss in accuracy, and point counting occupied an intermediate position. The present study was undertaken to compare the Reid Index as a measure of the gland area determination to the card-weighing method, utilizing photographs instead of sketches of projected images of bronchial wall tissue preparations. Since it was possible that the Reid Index could be unrelated to the total gland area but still correlate well with glands located between cartilage and the surface epithelium, the inner bronchial glands (between cartilage and epithelium), and the outer bronchial glands (peripheral to the cartilage), as well as the total Quantitative
219 Copyright Ail rights
@ 1973 by of reproduction
Academic Press. Inc. in any form reserved.
220
BEDROSSIAN,
GREENBERG,
AND
DURAN
gland values were computed separately. In addition, a ratio taking into account the area of the bronchial glands to the area of the bronchial lumen was also calculated in every case and included in the final statistical analysis. MATERIAL
AND METHODS
Twenty tissue preparations of bronchial walls were obtained from right lungs of five consecutive adult autopsies, disregarding the clinical settings since interest focused merely in comparing various morphometric data. In each specimen the four levels studied were (1) the main bronchus, just distal to the carina and (2, 3, and 4) the three lobar bronchi, just disal to their origin. The lungs were inflated with intrabronchial liquid formalin with a hydrostatic pressure of 25 cm water. After inflation the bronchus was ligitated and the lungs were fixed 5-7 days submerged in the same preservative. Cross sections of the bronchi were obtained, perpendicular to the long axis, and 5-r/m thin paraffin sections were prepared and stained by hematoxylin and eosin and periodic acid-SchifI methods. The slides were photographed on Pan-X black and white 35-mm film, using a Repronar copier with a green filter. The main bronchus was enlarged to almost completely fill the frame and then all other photographs were taken at the same magnification. Similarly, when printing the photographs, the main bronchus was enlarged to almost fill the 8 x 5-in. frame and all other negatives were printed at the same magnification, Bronchial glands, whether located inside, outside, or between the cartilaginous plates were outlined in their entirety, as were the epithelium, the outer limit of the bronchial wall and the cartilage plates. Measurements pertinent to the Reid Index as specified previously (Reid, 1960) were determined at or near the center of the cartilaginous ring regardless of the gland or wall thickness at this point. Paper cutouts of the glands and of the bronchial lumen were weighed on an electric analytical balance with special attention to the location of glands in relation to the cartilage. A factor was determined to transpose weight values into area by weighing known areas of the same paper in the same balance. (An attempt was made to print the photographs to a similar contrast so that the amount of silver would not vary the weight determinations of the cut-outs.) Total, inner, and outer gland values in three of the five lungs (12 different bronchi) were tabulated separately for the statistical analysis by the Correlation Coefficient Index. RESULTS Correlation Coefficient Indices between absolute values of gland areas obtained by the card-weight method and the two ratios analyzed (gland/wall and gland/lumen) are summarized in Table I. Both ratios correlated similarly with total gland area but this correlation was poor. The gland/wall ratio correlated better with outer than with inner glands and the same was true for the gland/ lumen ratio since glands are measured in their entirety, independent of their location in relation to the cartilage. It remains unexplained how the gland/wall ratio taken from inner glands correlated well with glands located externally to the cartilaginous plates. Correlation Coefficient Indices were determined by plotting against each other the values obtained by the card-weighing method
BRONCHIAL
GLAND TABLE
CORHI,:L.~TION hT10
COEFFICIENTS \?ilTH GL:\ND
221
MEASUREMENTS I
OF GL.~ND/W:~LL ARE.~S ESTIM.~TED
(I~xD INDEX) :IND UY CSRD-WEIGHING
GLAND/LUMEN i%THOD
Total
Outer
Inner
Gland/wall
r = 0.567 (P
r=0.718 (P <0.004)*
P-=0.157
Gland/lumen
r=O.566 (P <0.03)*
T = 0.601 (P
T = 0.252
a The P values given Coefficient is significantly
are those corresponding larger than zero.
to the assertion
that
the respective
Correlation
and both ratios as shown in Fig. 1. A wide scattering of points showing ( 1) high ratios with small total gland areas and (2) low ratios with large total gland areas was found. DISCUSSION Using independent techniques of bronchial gland measurements, variation of the amount of glands present in different bronchi of the same lung have been found (Restrepo and Heard, 1963b; Thurlbeck and Angus, 1967). Also, study has shown that the amount of glands does not correlate well statistically with the degree of chronic inflammation in the bronchial tree (Greenberg et al., 1967) and most recently a quantitation of bronchial mucous gland size in asthma showed an increase when assessed by the Dunnill point count but not by the Reid Index (Takizawa and Thurlbeck, 1971b). Nevertheless, bronchial gland hypertrophy remains the salient morphologic feature of chronic bronchitis, regardless of the preseme or absence of accompanying inflammatory infiltrate. Indeed, “bronchitis” defined as gland hypertrophy has been related to smoking (Thurlbeck et al., 1963; Mitchell et al., 1964)) air pollution (Ogilvie, 1960), and aging (Hernandez et al., 1965), while conflicting reports of hypertrophy (Thurlbeck and Angus, 1963) and no “overgrowth” (Hernandez et al., 1964) of between glands in emphysema are available. Cause and effect relationship chronic bronchitis and emphysema are also lacking in a study of the lobar distribution of both diseases (Greenberg et al., 1967).
.A
z-3
-
.
-
0
. I
2 =.2
0 -
0
2
A
6
8 GLAND
FIG. 1. Comparison of gland assessed ratios. Gland/lumen and with gland area deteminations.
ID
I2
,A
,6
,*
20
54.
mm
AREAS
areas determined gland/wall ratios
by the paralleled
card-weight each other
method and but correlated
the two poorly
222
BEDROSSIAN,
A.
cLnND=Ez LUMEN
C,--:-= GLAND LUMEN
GREENBERG,
AND DURAN
.50 20
IO IO
,,oo
FIG. 2. Cross sections of hypothetical bronchi. A. Normal bronchus with gland/lumen ratio of 0.50. B. True gland hyperplasia in presence of a normal luminal area; gland/lumen ratio is increased to 1.0 C. Gland/lumen ratio increased to 1.0 in presence of normal amount of glands but with reduction of luminal area.
The bronchial gland/wall ratio (later popularized as the Reid Index) was the first morphometric study reported in which the width of the bronchial glands compared to the width of the bronchial wall between the cartilage and epithelium correlated well with the amount of sputum produced in chronic bronchitis (Reid, 1960). A subseq uent report, however, failed to confirm these findings and the possibility of local bronchial disease, such as tuberculosis, influencing sputum production was suggested (Thurlbeck et al., 1963). As additional tissue studies of the Reid Index became available, it was evident that the procedure could screen between broad groups of bronchitic and nonbronchitic lungs, but its use as an exact diagnostic criterion in individual cases was questionable because of considerable overlap (Restrepo and Heard, 1963a; Thurlbeck et al., 1963; Thurlbeck and Angus, 1964). Specific technical limitations of the Reid Index method are: (1) influence of bronchial mucosa crenation, (2) artifactual separation between perichondrium and cartilage, (3) sites where glands and cartilage are not parallel, and (4) disregard of acini located in between or lateral to the cartilage plates (Dunnill et al., 1969; Bedrossian et al., 1971). For these reasons, attention has been directed toward alternative two-dimensional techniques for quantitating bronchial glands. Measurements of gland area by planimetry have been performed but require considerable amounts of time (Hale et al., 1968; Bedrossian et al., 1971). Card weighing, as applied to sketches of projected images, seemsto show good results (Restrepo and Heard, 1963a; Restrepo and Heard, 1963b; Bedrossian et al., 1971). Point count has also been undertaken since it is relatively simple to perform (Hale et al., 1968; Dunnill et al., 1969; Bedrossian et al., 1971). In general, results by these methods correlate well with each other (Hale et al., 1968; Bedrossian et al., 1971); however, when expressed as absolute values
BRONCHIAL
GLAND
MEASUREMENTS
223
of gland area, these procedures do not allow for variations or tissue artifacts such as shrinkage and tangential sectioning (Ogilvie, 19sO). Other techniques of estimating bronchial gland hypertrophy are acinar counts per microscopic high-power field (Reid, 1960) and the ratio of mucous to serous acini (Glynn and Michaels, 1960), but a recent investigation showed poor correlation of both with gland area calculation (Bedrossian et aZ., 1971) and poor correlation of the latter with the Reid Index (Takizawa and Thurlbeck, 1971a). The present report confirms a recent study in which correlation between the Reid Index and tota absolute gland area estimation by the card-weighing method was poor (Bedrossian et al., 1971). Moreover, in the present investigation no relation was found between the Reid Index and the areas of the inner glands from which it is computed. Instead, better correlation was found with the outer glands which are not included in the gland/wall ratio. The new index herein proposed, namely, gland/lumen ratio, had the advantage of including total gland area as relates to the area of the lumen so that an increased value may indicate not only gland hypertrophy but also a decrease in cross-sectional luminal area (Fig. 2). ACKNOWLEDGMENTS The authors thank Dr. Robert M. O’Neal for his encouragement and guidance in this study and Mrs. Connie Leach and Mrs. Vicky Mayfield for preparing the manuscript. REFERENCES American Thoracic Society ( 1962). Definitions and classification of chronic bronchitis, asthma, and pulmonary emphysema. Amer. Rev. Resp. Dis. 85,762-769. BEDROSSIAN, C. W. M., ANDERSON, A. E., and FORAKER, A. G. ( 1971). Comparison of methods for quantitating bronchial morphology. Thorax 26,406-408. DUNNILL, M. S., MASSAFIELLA, G. R., and ANDERSON, J. A. ( 1969). A comparison of the quantitative anatomy of the bronchi in normal subjects, in status asthmaticus, in chronic bronchitis, and in emphysema. Thorax 24, 176-179. GLYNN, A. A., and MICHAELS, L. (1960). Bronchial biopsy in chronic bronchitis and asthma. ThOfUX 14,142153. GREENBERG, S. D., BOUSHY, S. F., and JENKINS, D. E. (1967). Chronic bronchitis and emphysema: Correlation of pathologic findings. Amer. Rev. Resp. Dis. 96,918-928. HALE, F. C., OLSEN, C. R., and MICKEY, M. R. (1968). The measurement of bronchial wall components. Amer. Rev. Resp. Dis. 98, 978-987. HERNANDEZ, J. A., ANDERSON, A. E., JR., and FORAKER, A. G. (1964). Bronchial characteristics in pulmonary emphysema. Arch. Pathol. 77, 82-92. HERNANDEZ, J. A., ANDERSON, A. E., JR., HOLMES, W. L., MORRONE, N., and FORAKER, A. G. ( 1965). The bronchial glands in aging. J. Amer. Geriat. Sot. 13,799-804. MACLEOD, L. J., and HEARD, B. E. (1969). A rea of muscle in tracheal sections in chronic bronchitis, measured by point counting. J. Pathol. 97,157-161. MITCHELL, R. S., VINCENT, T. M., and FILLEY, F. G. (1964). Cigarette smoking, chronic bronchitis, and emphysema. J. Amer. Med. Ass. 188, 12-16. OGILVIE, A. G. (1960). Social and environmental factors in chronic bronchitis in Newcastle upon Tyne. Postgrad. Med. J. 36,261-269. REID, L. (1960). Measurement of the bronchial mucous gland layer: A diagnostic yardstick in chronic bronchitis. Thorax 15, 132-141. RESTREPO, G. L., and HEARD, B. E. ( 1963). Th e size of the bronchial glands in chronic bronchitis. J. PathoE. Bacterial. 85, 305-310. RESTREPO, G. L., and HEARD, B. E. (1963). Mucous gland enlargement in chronic bronchitis: Extent of enlargement in the trachea-bronchial tree. Thorax 18,334-339.
224
BEDROSSIAN,
GREENBERG,
AND
DURAN
TAKIZAWA, T., and TWRLBECK, W. M. ( 1971). A comparative study of four methods of assessing the morphologic changes in chronic bronchitis. Amer. Rev. Resp. Dis. 103, 774783. TAKIZAWA, T., and THURLBECK, W. M. ( 1971). Muscle and mucous gland size in the major bronchi of patients with chronic bronchitis, asthma, and asthmatic bronchitis. Amer. Rev. Resp. Dis. 104, 331-336. TANDON, M. K., and ALASTAIR, H. C. (1969). Bronchial cartilage in chronic bronchitis. Thorax 24,607*12. THIJRLBECK, W. M., and ANGUS, G. E. (1963). The relationship between emphysema and chronic bronchitis as assessed morphologically. Amer. Rev. Resp. Dis. 87, 815-819. THURLBECK, W. M., ANGUS, G. E., and PARE, J. A. P. (1963). Mucous gland hypertrophy in chronic bronchitis and its occurrence in smokers. Brit. .I. Dis. Chest 57, 73-78. THIJRLBECK, W. M., and ANGUS, G. E. (1964). A distribution curve for chronic bronchitis. Thorax 19,436442. THURLBECK, W. M., and ANGUS, G. E. (1967). Th e variation of Reid index measurements within the major bronchial tree. Amer. Rev. Resp. Dis. 95, 551-555.
ASD
KIOLECULAR
PATHOLOGY
Bronchial A Continuing
18,
219-224
Gland Measurements: Search for a “Yardstick”
CARLOS W. M. BEDROSSIAN, AND Departments
of Pathology Received
July
(1973)
S. DONALD
and Biomathematics, Baylor Houston, Texas 77025 18, 1972;
GREENBERG,
S. DURAN
BENJAMIN
accepted
October
College
of Aletlicine,
2, 1972
Bronchial morphometry has been the object of great interest in the past few years. A recent investigation showed poor correlation between the Reid Index and gland area determinations by a variety of methods. In the present stndy, gland/ wall ratio (Reid Index) was compared with estimation of total, inner, and outer gland areas by the card-weighing method. Correlation was in general poor but unexpectedly presented a lower Coefficient Index for glands located internal than for those located external to the cartilage. A new proposed index of gland/lumen ratio has the advantage of including information not only about the glands in their entirety, but also the crosssectional luminal area of bronchi.
morphology of the bronchi has been the object of several studies in the last few years (Reid, 1960; Restrepo and Heard, 1963a; Restrepo and Heard, 196313;Hale et al., 1968; Dunnill et al., 1969; Macleod and Heard, 1969; Tanden and Alastair, 1969), and various morphometric methods have been applied to assessbronchial wall glands (Reid, 1960; Restrepo and Heard, 1963a; Restrepo and Heard, 1963b), cartilage (Tanden and Alastair, 1969), and smooth muscle (Macleod and Heard, 1969). Among these, the bronchial glands have received the greatest attention, for hypertrophy of these structures is believed to be the hallmark of chronic bronchitis (American Thoracic Society, 1962). A recent comparison of bronchial gland measurements by different techniques revealed the Reid Index to correlate poorly with total gland areas expressed as absolute values (Bedrossian, et al., 1971). In contrast, determination of gland area by such methods as planimetry, point count, and ‘card weighing correlated very well with each other. Planimetry, while the most accurate, proved to be tedious, card weighing showed considerable saving in time without loss in accuracy, and point counting occupied an intermediate position. The present study was undertaken to compare the Reid Index as a measure of the gland area determination to the card-weighing method, utilizing photographs instead of sketches of projected images of bronchial wall tissue preparations. Since it was possible that the Reid Index could be unrelated to the total gland area but still correlate well with glands located between cartilage and the surface epithelium, the inner bronchial glands (between cartilage and epithelium), and the outer bronchial glands (peripheral to the cartilage), as well as the total Quantitative
219 Copyright Ail rights
@ 1973 by of reproduction
Academic Press. Inc. in any form reserved.
220
BEDROSSIAN,
GREENBERG,
AND
DURAN
gland values were computed separately. In addition, a ratio taking into account the area of the bronchial glands to the area of the bronchial lumen was also calculated in every case and included in the final statistical analysis. MATERIAL
AND METHODS
Twenty tissue preparations of bronchial walls were obtained from right lungs of five consecutive adult autopsies, disregarding the clinical settings since interest focused merely in comparing various morphometric data. In each specimen the four levels studied were (1) the main bronchus, just distal to the carina and (2, 3, and 4) the three lobar bronchi, just disal to their origin. The lungs were inflated with intrabronchial liquid formalin with a hydrostatic pressure of 25 cm water. After inflation the bronchus was ligitated and the lungs were fixed 5-7 days submerged in the same preservative. Cross sections of the bronchi were obtained, perpendicular to the long axis, and 5-r/m thin paraffin sections were prepared and stained by hematoxylin and eosin and periodic acid-SchifI methods. The slides were photographed on Pan-X black and white 35-mm film, using a Repronar copier with a green filter. The main bronchus was enlarged to almost completely fill the frame and then all other photographs were taken at the same magnification. Similarly, when printing the photographs, the main bronchus was enlarged to almost fill the 8 x 5-in. frame and all other negatives were printed at the same magnification, Bronchial glands, whether located inside, outside, or between the cartilaginous plates were outlined in their entirety, as were the epithelium, the outer limit of the bronchial wall and the cartilage plates. Measurements pertinent to the Reid Index as specified previously (Reid, 1960) were determined at or near the center of the cartilaginous ring regardless of the gland or wall thickness at this point. Paper cutouts of the glands and of the bronchial lumen were weighed on an electric analytical balance with special attention to the location of glands in relation to the cartilage. A factor was determined to transpose weight values into area by weighing known areas of the same paper in the same balance. (An attempt was made to print the photographs to a similar contrast so that the amount of silver would not vary the weight determinations of the cut-outs.) Total, inner, and outer gland values in three of the five lungs (12 different bronchi) were tabulated separately for the statistical analysis by the Correlation Coefficient Index. RESULTS Correlation Coefficient Indices between absolute values of gland areas obtained by the card-weight method and the two ratios analyzed (gland/wall and gland/lumen) are summarized in Table I. Both ratios correlated similarly with total gland area but this correlation was poor. The gland/wall ratio correlated better with outer than with inner glands and the same was true for the gland/ lumen ratio since glands are measured in their entirety, independent of their location in relation to the cartilage. It remains unexplained how the gland/wall ratio taken from inner glands correlated well with glands located externally to the cartilaginous plates. Correlation Coefficient Indices were determined by plotting against each other the values obtained by the card-weighing method
BRONCHIAL
GLAND TABLE
CORHI,:L.~TION hT10
COEFFICIENTS \?ilTH GL:\ND
221
MEASUREMENTS I
OF GL.~ND/W:~LL ARE.~S ESTIM.~TED
(I~xD INDEX) :IND UY CSRD-WEIGHING
GLAND/LUMEN i%THOD
Total
Outer
Inner
Gland/wall
r = 0.567 (P
r=0.718 (P <0.004)*
P-=0.157
Gland/lumen
r=O.566 (P <0.03)*
T = 0.601 (P
T = 0.252
a The P values given Coefficient is significantly
are those corresponding larger than zero.
to the assertion
that
the respective
Correlation
and both ratios as shown in Fig. 1. A wide scattering of points showing ( 1) high ratios with small total gland areas and (2) low ratios with large total gland areas was found. DISCUSSION Using independent techniques of bronchial gland measurements, variation of the amount of glands present in different bronchi of the same lung have been found (Restrepo and Heard, 1963b; Thurlbeck and Angus, 1967). Also, study has shown that the amount of glands does not correlate well statistically with the degree of chronic inflammation in the bronchial tree (Greenberg et al., 1967) and most recently a quantitation of bronchial mucous gland size in asthma showed an increase when assessed by the Dunnill point count but not by the Reid Index (Takizawa and Thurlbeck, 1971b). Nevertheless, bronchial gland hypertrophy remains the salient morphologic feature of chronic bronchitis, regardless of the preseme or absence of accompanying inflammatory infiltrate. Indeed, “bronchitis” defined as gland hypertrophy has been related to smoking (Thurlbeck et al., 1963; Mitchell et al., 1964)) air pollution (Ogilvie, 1960), and aging (Hernandez et al., 1965), while conflicting reports of hypertrophy (Thurlbeck and Angus, 1963) and no “overgrowth” (Hernandez et al., 1964) of between glands in emphysema are available. Cause and effect relationship chronic bronchitis and emphysema are also lacking in a study of the lobar distribution of both diseases (Greenberg et al., 1967).
.A
z-3
-
.
-
0
. I
2 =.2
0 -
0
2
A
6
8 GLAND
FIG. 1. Comparison of gland assessed ratios. Gland/lumen and with gland area deteminations.
ID
I2
,A
,6
,*
20
54.
mm
AREAS
areas determined gland/wall ratios
by the paralleled
card-weight each other
method and but correlated
the two poorly
222
BEDROSSIAN,
A.
cLnND=Ez LUMEN
C,--:-= GLAND LUMEN
GREENBERG,
AND DURAN
.50 20
IO IO
,,oo
FIG. 2. Cross sections of hypothetical bronchi. A. Normal bronchus with gland/lumen ratio of 0.50. B. True gland hyperplasia in presence of a normal luminal area; gland/lumen ratio is increased to 1.0 C. Gland/lumen ratio increased to 1.0 in presence of normal amount of glands but with reduction of luminal area.
The bronchial gland/wall ratio (later popularized as the Reid Index) was the first morphometric study reported in which the width of the bronchial glands compared to the width of the bronchial wall between the cartilage and epithelium correlated well with the amount of sputum produced in chronic bronchitis (Reid, 1960). A subseq uent report, however, failed to confirm these findings and the possibility of local bronchial disease, such as tuberculosis, influencing sputum production was suggested (Thurlbeck et al., 1963). As additional tissue studies of the Reid Index became available, it was evident that the procedure could screen between broad groups of bronchitic and nonbronchitic lungs, but its use as an exact diagnostic criterion in individual cases was questionable because of considerable overlap (Restrepo and Heard, 1963a; Thurlbeck et al., 1963; Thurlbeck and Angus, 1964). Specific technical limitations of the Reid Index method are: (1) influence of bronchial mucosa crenation, (2) artifactual separation between perichondrium and cartilage, (3) sites where glands and cartilage are not parallel, and (4) disregard of acini located in between or lateral to the cartilage plates (Dunnill et al., 1969; Bedrossian et al., 1971). For these reasons, attention has been directed toward alternative two-dimensional techniques for quantitating bronchial glands. Measurements of gland area by planimetry have been performed but require considerable amounts of time (Hale et al., 1968; Bedrossian et al., 1971). Card weighing, as applied to sketches of projected images, seemsto show good results (Restrepo and Heard, 1963a; Restrepo and Heard, 1963b; Bedrossian et al., 1971). Point count has also been undertaken since it is relatively simple to perform (Hale et al., 1968; Dunnill et al., 1969; Bedrossian et al., 1971). In general, results by these methods correlate well with each other (Hale et al., 1968; Bedrossian et al., 1971); however, when expressed as absolute values
BRONCHIAL
GLAND
MEASUREMENTS
223
of gland area, these procedures do not allow for variations or tissue artifacts such as shrinkage and tangential sectioning (Ogilvie, 19sO). Other techniques of estimating bronchial gland hypertrophy are acinar counts per microscopic high-power field (Reid, 1960) and the ratio of mucous to serous acini (Glynn and Michaels, 1960), but a recent investigation showed poor correlation of both with gland area calculation (Bedrossian et aZ., 1971) and poor correlation of the latter with the Reid Index (Takizawa and Thurlbeck, 1971a). The present report confirms a recent study in which correlation between the Reid Index and tota absolute gland area estimation by the card-weighing method was poor (Bedrossian et al., 1971). Moreover, in the present investigation no relation was found between the Reid Index and the areas of the inner glands from which it is computed. Instead, better correlation was found with the outer glands which are not included in the gland/wall ratio. The new index herein proposed, namely, gland/lumen ratio, had the advantage of including total gland area as relates to the area of the lumen so that an increased value may indicate not only gland hypertrophy but also a decrease in cross-sectional luminal area (Fig. 2). ACKNOWLEDGMENTS The authors thank Dr. Robert M. O’Neal for his encouragement and guidance in this study and Mrs. Connie Leach and Mrs. Vicky Mayfield for preparing the manuscript. REFERENCES American Thoracic Society ( 1962). Definitions and classification of chronic bronchitis, asthma, and pulmonary emphysema. Amer. Rev. Resp. Dis. 85,762-769. BEDROSSIAN, C. W. M., ANDERSON, A. E., and FORAKER, A. G. ( 1971). Comparison of methods for quantitating bronchial morphology. Thorax 26,406-408. DUNNILL, M. S., MASSAFIELLA, G. R., and ANDERSON, J. A. ( 1969). A comparison of the quantitative anatomy of the bronchi in normal subjects, in status asthmaticus, in chronic bronchitis, and in emphysema. Thorax 24, 176-179. GLYNN, A. A., and MICHAELS, L. (1960). Bronchial biopsy in chronic bronchitis and asthma. ThOfUX 14,142153. GREENBERG, S. D., BOUSHY, S. F., and JENKINS, D. E. (1967). Chronic bronchitis and emphysema: Correlation of pathologic findings. Amer. Rev. Resp. Dis. 96,918-928. HALE, F. C., OLSEN, C. R., and MICKEY, M. R. (1968). The measurement of bronchial wall components. Amer. Rev. Resp. Dis. 98, 978-987. HERNANDEZ, J. A., ANDERSON, A. E., JR., and FORAKER, A. G. (1964). Bronchial characteristics in pulmonary emphysema. Arch. Pathol. 77, 82-92. HERNANDEZ, J. A., ANDERSON, A. E., JR., HOLMES, W. L., MORRONE, N., and FORAKER, A. G. ( 1965). The bronchial glands in aging. J. Amer. Geriat. Sot. 13,799-804. MACLEOD, L. J., and HEARD, B. E. (1969). A rea of muscle in tracheal sections in chronic bronchitis, measured by point counting. J. Pathol. 97,157-161. MITCHELL, R. S., VINCENT, T. M., and FILLEY, F. G. (1964). Cigarette smoking, chronic bronchitis, and emphysema. J. Amer. Med. Ass. 188, 12-16. OGILVIE, A. G. (1960). Social and environmental factors in chronic bronchitis in Newcastle upon Tyne. Postgrad. Med. J. 36,261-269. REID, L. (1960). Measurement of the bronchial mucous gland layer: A diagnostic yardstick in chronic bronchitis. Thorax 15, 132-141. RESTREPO, G. L., and HEARD, B. E. ( 1963). Th e size of the bronchial glands in chronic bronchitis. J. PathoE. Bacterial. 85, 305-310. RESTREPO, G. L., and HEARD, B. E. (1963). Mucous gland enlargement in chronic bronchitis: Extent of enlargement in the trachea-bronchial tree. Thorax 18,334-339.
224
BEDROSSIAN,
GREENBERG,
AND
DURAN
TAKIZAWA, T., and TWRLBECK, W. M. ( 1971). A comparative study of four methods of assessing the morphologic changes in chronic bronchitis. Amer. Rev. Resp. Dis. 103, 774783. TAKIZAWA, T., and THURLBECK, W. M. ( 1971). Muscle and mucous gland size in the major bronchi of patients with chronic bronchitis, asthma, and asthmatic bronchitis. Amer. Rev. Resp. Dis. 104, 331-336. TANDON, M. K., and ALASTAIR, H. C. (1969). Bronchial cartilage in chronic bronchitis. Thorax 24,607*12. THIJRLBECK, W. M., and ANGUS, G. E. (1963). The relationship between emphysema and chronic bronchitis as assessed morphologically. Amer. Rev. Resp. Dis. 87, 815-819. THURLBECK, W. M., ANGUS, G. E., and PARE, J. A. P. (1963). Mucous gland hypertrophy in chronic bronchitis and its occurrence in smokers. Brit. .I. Dis. Chest 57, 73-78. THIJRLBECK, W. M., and ANGUS, G. E. (1964). A distribution curve for chronic bronchitis. Thorax 19,436442. THURLBECK, W. M., and ANGUS, G. E. (1967). Th e variation of Reid index measurements within the major bronchial tree. Amer. Rev. Resp. Dis. 95, 551-555.