IgG and Albumin Turnover in Crohn’s Disease

G. BENDIXEN, s. JARNUM, J . SOLTOFT, H. WESTERGAARD, B. WEEKE & MlNNA YSSlNG

Medical Department P, Division of Gastroenterology, Rigshospitalet, and Department of Clinical Chemistry, Bispebjerg Hospital, Copenhagen, Denmark

Abstract: BENDIXEN, G., JARNUM, S., SBLTOFT, J., WESTERGAARD, H., WEEKE, B & YSSING, MINNA. IgG and Albumin Turnover in Crohn’s Disease. Scand. J. Gastroent. 3, 481-489, 1968. Simultaneous IgG and albumin turnover studies were performed in 10 patients with Crohn’s disease of the tern-inal ileum, the colon, or both, by means of radioiodinated proteins. An abnormal intestinal protein loss was demonstrated in everyone with 6BFe-labelled iron dextran. The serum level of IgG was normal in 5 and elevated in 3 cases. The higher the serum level, the higher was the fractional catabolic rate (per cent of intravascular mass catabolized per day). The synthetic rate was markedly increased in most cases. In contrast, serum albumin was negatively correlated to its catabolic rate. Albumin synthesis was normal or moderately elevated. The regression between the catabolic rates of IgG and albumin in 7 cases of in- testinal lyrnphangixtasia and in locases of Crohn’s disease suggested that, in intestinal lymphangiectasia, the protein loss of albumin was higher than that of IgG, whereas, in Crohn’s disease, the IgG catabolism for unknown reasons was higher than that of albumin. All patients with Crohn’s disease had normal serum levels of IgA and IgM. The leucocyte migration test with small intestine or colon mucosa as antigens was normal in all cases of Crohn’s disease. This is in contrast to the findings in ulcerative colitis where a cellular hypersensitivity to these antigens has been demonstrated. It is concluded that the ability to develop humoral hypersensitivity is probably nxmal in Crohn’s disease. An abnormally high fraction of the total mass of both IgG and albumin was present intravascularly in most patients. Faecal radioiodine excretion from labelled IgG and albumin was high in patients with colonic involvement. In patients with terminal ileitis the faecal excretion of the IgG-label was higher than that of the albumin-label.

Key-words: Intestine, small; enteritis, regional ; immunoglobulins; albumin; protcin-losing enteropathy ; iron-dextran complcx; autoimmune diseases; hypersensitivity; radioisotopes

Stig Jarnum, M. D., Medical Department P , Rigshospitalet, 2IOO Copenhagen 0, Denmark

An abnormal immune reactivity seems t o be a remarkable feature of Crohn’s disease. The incidence of a negative Mantoux reaction is high compared t o matched controls (Phear 1958). Contrary t o ulcerative colitis, the disease is not associated with a specifically altered reactivity of peripheral leucocytes t o colon or small intestine antigen as judged from the leucocyte migration test (Bendixen 1967).

3. Scand. J . Cmtroent.

The incidence of antibodies against milk proteins (lactalbumin and lactoglobulin) is significantly lower than in controls. Such anti- bodies occur with increased frequency in ul- cerative colitis and other gastrointestinal dis- eases (Taylor 1965).

In spite of these observations, which suggest that Crohn’s disease is associated with a state of immunological hyporeactivity, the concen-

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482 G. BENDIXEN, S. JARNUM, J. SPILTOFT, H. WESTERGAARD, B. WEEKE & MlNNA YSSING

Table I. Ten cases of Crohn’s disease. Localization of the lesion and some laboratory data

Blood Patient Age Height Hgb ESR in stools

No. Sex Weight g/100 rnl mrn/h (benzidine) LMT* Mantoux**

Terminal ileum

lleumicolon

Colon

1. 57 F

2. 48 M

3. 22 F

4. 64 F

5. 23 M

6. 37 M

7. 31 M

8. 15 M

9. 49 F

10. 23 F

156 crn 47 kg 170 crn 62 kg 162 crn 53 kg 158 crn 55 kg

170 crn 44 kg 178 cm 61 kg 173 crn 57 kg 180 cm 65 kg

161 crn 48 kg 166 cm 51 kg

8.9

12.1

10.7

13.0

12.1

10.8

13.8

9.8

10.6

6.9

56 + - 0

7 0

25 0

39 0

40 0 - ( + )

8 +++ 10 ++ 10 +++

5 ++ 88 ++

C 0.83 S 0.89 C 0.93 S 0.84 C 0.85 S 0.97 c 1.12 s 1.00

C 0.95 s 1.12 C 1.03 S 1.07 C 0.90 S 0.83 C 1.14 s 1.00

C 0.92 S 0.94 c 1.01 S 0.84

M I neg. M I1 pos. M I pos.

M I neg. M I1 pos.

-

M I neg.

M I pos.

M I neg. M I1 neg.

-

M I pos.

M I pos.

C = Colon S =Small intestine

**MI: 1 unit * LMT: Leucocyte migration test

MII: 10 units

tration of immunoglobulins in serum is usu- ally normal or only slightly altered. A normal immunoglobulin level might in fact reflect an increased synthetic rate, since the disease re- gularly causes an abnormal intestinal protein loss. This again might imply a normal capac- ity of the immune organ to produce extra- cellular immunoglobulins and, presumably, to convey a state of humoral hypersensitivity.

Exact data on the degradation rate and synthesis can only be obtained by means of labelled proteins. Since the degradation rate of albumin is an index of intestinal protein loss, concurrent studies with labelled albumin

Normal range C 0.79-1.1 1 S 0.78-1.10

and immunoglobulin would be particularly useful, since they would yield information on the influence of abnormal protein loss per se on the metabolism of the immunoglogulin. However, at the same time one must establish the presence and approximate size of abnor- mal gastrointestinal protein loss by means of a test substance like 59Fe-labelled iron dex- tran or WrC13.

We here report the results of turnover studies in 10 cases of Crohn’s disease. They were examined with 131I-albumin, 125I-IgG and 5gFe-labelled iron dextran. For the sake of comparison similar studies were performed

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IgG AND ALBUMIN TURNOVER IN CROHN’S DISEASE 483

in 7 cases of intestinal lymphangiectasia, a non-inflammatory condition in which the as- sociated intestinal protein loss is usually much more pronounced than in Crohn’s disease.

CASE MATERIAL

Crohn’s disease (Table I). Ten patients, 5 females and 5 males, aged from 15 to 64 years, were studied. Intestinal resection had been performed in 6 cases and the diagnosis confirmed by the patho-anatomical findings. In the remaining 4 cases the diagnosis was based on sigmoidoscopy, radiography and clin- ical symptoms. Four suffered from terminal ileitis, 4 from ileocolitis and 2 from regional colitis. In 4 patients (case Nos. 5, 6, 8 and 10) the

disease was highly active (weight loss, fever, elevated ESR, diarrhea several times daily). In the remaining 6 cases the disease was moderately active.

One patient had slightly elevated glutamic pyruvic acid transaminase. In the remaining 9 cases hepatic function appeared normal ac- cording to alcaline phosphatases, serum bili- rubin and glutamic pyruvic acid transaminases.

Patients Nos. 5, 6 and 8 were treated with salazopyrin, and in case No. 8 one liter of blood was given during the protein turnover study. No patients received steroids at the time of the investigation.

Controls. Eleven subjects aged from 29 to 91 years without diseases affecting the serum protein pattern served as controls. All had normal ESR, haemoglobin level and serum creatinine. None had proteinuria. Serum paper electrophoresis and serum protein (biuret) were normal. Albumin turnover was within normal limits.

Other protein-losing enteropathies. For the sake of comparison, studies made in 7 cases of intestinal lymphangiectasia were included. The diagnosis was confirmed by post-mortem examination, operation or biopsy in 6 patients.

In one case the diagnosis was likely, since the patient had a congenital malabsorption syndrome, hypoalbuminaemia with oedema and gastrointestinal protein loss.

METHODS Radioiodine-labelled proteins

IZV-IgG. IgG was isolated from normal human serum by DEAE column chromato- graphy and labelled with 1 Z 5 1 by means of Mc- Farlane’s monoiodine chloride method (for de- tails: see Andersen 1964 and Andersen, Jarnum, Jensen &Rossing 1968). In the final prepara- tion, more than 99.5 per cent of the label was proteinbound.

1311-albumin. Human serum albumin (‘AI- bumin trocken reinst’, Behringwerke, Mar- burg, Lahn, Germany) was similarly labelled with ln*I (for details: see Rossing & Jensen 1967).

“Fe-labelled iron dextran. Iron dextran la- belled with “Fe in stable bond (Benger Research Laboratories, Holmes Chapel, Che- shire, England) was used for detection and quantitative estimation of gastrointestinal pro- tein loss (Andersen & Jarnum 1966).

Experimental proceditre Thyroid blocking of radioiodine uptake was

secured by oral administration of potassium iodide (40 mg I daily) throughout the study.

The subjects received within 1 to 2 minutes intravenous injections of 12sII-IgG, 13”Z-albu- min and “Fe-iron dextran. About 0.2 pCi 1251, 0.5 I‘Ci 1311 and 0.1 $i “Fe per kg were given, which amounted to a total body radiation dose of about 500 mrem.

Blood samples were withdrawn in heparin- ized tubes 10-15 minutes after the injection and at daily intervals for 10 to 14 days.

Twenty-four hour urinary collections were made, and stools were collected at daily inter- vals until they became red following oral administration of 1 g carmine 96 hours after the injections.

Plasma and urine (3 ml samples) and weighed duplicates of homogenized stools were

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484 G . BENDIXEN, S. JARNUM, J. SBLTOFT, H. WESTERGAARD, B. WEEKE S! MINNA YSSING

counted in a 3 channel gammaspectrometer ('Autogammaspectrometer', Packard). The counting period was 10 minutes, the counting efficiency about 50 per cent for 1251 and 1311

and 30 per cent for 59Fe. Samples with a net count of less than 20 per cent of the back- ground were considered to contain no signif- icant amount of radioactivity. Each of the 3 channels was set for the peak energy of gamma rays from either 1251, 1311 or 59Fe.

The cumulative excretion of 59Fe and 1311 was measured daily in a whole body counter (Jarnum, Westergaard, Yssing & Jensen 1968) for a period of 8 to 14 days.

Calculations Protein turnover was calculated after Noss-

link method (Andersen 1964), which makes use of a mathematical analysis of the plasma activity curve. Metabolic clearance (urinary radioiodine excretion divided by simultaneous plasma activity) together with whole body counting was used as a check and showed a reasonably fair agreement with the data de- rived by Nosslin's method.

The following parameters were applied: Fractional catabolic rate (FCR): Fraction (or percentage) of intravascular mass of the pro- tein catabolized per day.

Synthetic rate: FCR x intravascular mass, g per day.

Distribution ratio (D): Intravascular mass as fraction (or percentage) of the total mass.

Gastrointestinal protein loss was estimated from faecal 5gFe-excretion, either as percent- age of the dose injected, or better, as the gastrointestinal clearance of plasma-59Fe which is well correlated with the size of the protein loss (Jarnum et al. 1968).

Serum concentrations of immunoglobulins were determined by electrophoresis in anti- body-containing agarose after carbamylation of the immunoglobulins (Weeke 1968).

Leucocyte migration test (LMT) The LMT was performed according to a

capillary tube migration technique elsewhere

described (Bendixen 1967). The method makes possible a quantitative evaluation of the in vitro migration of peripheral human leuco- cytes. The antigen-induced inhibition of the migration is an in vitro correlate to cellular (delayed type) hypersensitivity. The influence of an antigen upon the migration is expressed as a migration index (MI), which is calculated in the following way:

Mx Mo

MI =

where Mx is the mean 24-hour migration area of a series of antigen-containing cultures, and Mo the mean 24-hour migration area of a series of antigen-free cultures. MI thus in- dicates an inhibition if it is lower than unity, and a stimulation if it is higher. Homogenates of foetal colonic and small intestinal mucosa were used as antigens, and homogenates of liver and kidney were used in parallel experi- ments to test tissue specificity. The normal range (mean f 2 SD) of MI based on 55 controls was 0.79-1.11 with colon mucosa and 0.78-1.10 with small intestinal mucosa. Liver and kidney homogenates did not influence the migration.

RESULTS No major alteration was found in the serum concentrations of the immunoglobulins. Serum IgG was normal in 5 cases, decreased in 2 and elevated in 3. Serum IgA was elevated in one and normal in the remaining patients. Serum IgM was normal in every case. Serum albumin was decreased in all patients.

An abnormal intestinal protein loss was pre- sent in everyone, since faecal 59Fe excretion was elevated. I t measured from 1.6 to 7.7 per cent of the injected dose in 4-5 days as op- posed to a normal figure of less than 1 per cent. This also applied to the faecal clearance of 59Fe. which was from 1.9 to 7.3 per cent of the intravascular 59Fe per day (normal figure: less than 0.8 per cent per day).

The fractional catabolic rate of IgG was in- creased in all patients. When related to serum

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Igc AND ALBUMIN TURNOVER IN CROHN’S DISEASE 485

r?‘

3 P i Ij b % 8 10-

8

to 20 per cent). In patients with terminal . ileitis it was lower, but in these patients radioiodine from IgG exceeded that of albumin by a factor of 2 to 4.

The leucocyte migration test showed a nor- ma1 migration index with both types of antigen

. 8

8 . . 8 8

* * (colon and small intestine) in all cases.

DISCUSSION

in all cases but one, since an increased fraction of the total protein mass was present in- travascularly (Fig. 3).

04 + 0 5 10 15

SERJM I g G, MG/ML

Fig. 1. Serum level and catabolic rate of IgG and albumin in Crohn’s disease.

IgG. (Fig. l), it is seen that the catabolic rate was highest in patients with a high serum level, which is quite in contrast to albumin catabolism, which was highest in patients with a low serum albumin. The synthetic rate of IgG was ele- vated in 7 of 10 patients, the maximum figure being 9 times the normal mean (Table 11). Albumin synthesis was elevated in 2 cases and in no instance decreased.

There was a significant correlation between the catabolic rate of albumin and IgG, a finding which also applied to another protein- losing condition, intestinal lymphangiectasia (Fig. 2). However, at a certain level of albumin hypercatabolism, the associated increase of IgG catabolism was more pronounced in Crohn’s disease.

The distribution of IgG and albumin be- tween intravascular and extravascular masses in patients with Crohn’s disease was abnormal

The present studies have shown that profound alterations of the metabolic pattern of IgG take place in Crohn’s disease despite the fact that the serum concentration of IgG often remains within normal range. Thus, the cata- bolic rate of IgG was elevated in all cases. Furthermore, it was found that the catabolism was most accelerated in patients with the highest serum concentration of IgG (Fig. 1). Since the serum level is the net result of the balance between catabolic and synthetic rates, it can be inferred that, in relative terms, the synthetic rate of IgG in patients with elevated serum levels is increased even more than thc catabolic rate.

Comparing catabolic rate and serum level of albumin, a negative correlation was found to be present: the higher the catabolic rate of albumin, the lower the serum albumin, which is a well-known observation in gastro- intestinal protein loss because albumin synthe- sis is little affected and the catabolic rate of albumin reflects the size of abnormal protein loss (Jarnum et al. 1968). Concordantly, a sig- nificant correlation was found in the present series between the catabolic rate of albumin and the faecal clearance of SgFe-iron dextran (r = 0.90, p < 0,001). For IgG there was also

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486 G. BENDIXEN, S . JARNUM, J. SBLTOFT, H. WESTERGAARD, B. WEEKE & MINNA YSSlNG

Table 11. Serum levels of immunoglobulins and albumin and the results of studies

Serum concentration of ~ ~

Patient IgG IgA IgM Serum albumin mg/ml mg/ml mg/ml g/100 rnl

Normal ranges 7.15-15.10 0.74-3.06 0.23-1.33 3.77-5.55

Terminal ileum 1. 12.4 1.53 1.31 2.64 2. 7.0 1 .oo 0.35 2.87 3. 9.9 1.66 0.46 3.47' 4. 10.7 1.84 0.96 4.20*

Ileum -+ colon 5 . 18.6 5.52 0.86 1.73 6. 16.1 2.89 0.49 I .97 7. 14.6* 3.17* 8. 16.8 I .49 0.36 2.66

Colon 9. 4.3 0.80 0.75 2.82 10. 8.0 0.74 0.54 2.29

The serum concentrations of IgG, IgA, IgM, and albumin were determined irnmunochemically (Weeke 1968).

** FCR=fractional catabolic rate in per cent of intravascular mass degraded per day. * Determined by paper electrophoresis.

a positive correlation between fractional cata- bolic rate and faecal 59Fe-clearance (r = 0.60), but it was less significant (0.05 > p > 0.02).

t

M. CATABOLK WIT€ OF ALBUMIN *A OF 1 V P PER DAY

Fig. 2. Catabolic rate of albumin and IgG in Crohn's disease. (e) and intestinal lymphangiestasia (0).

The catabolic rate of IgG was, with one ex- ception, higher than that of albumin, the regression being:

Fig. 3. Distribution of albumin and IgG. D=intravascular pool as per cent of total pool.

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IgG AND ALBUMIN TURNOVER IN CROHN’S DISEASE 487

with radioiodinated IgG and 60Fe-labelled iron dextran in 10 cases of Crohn’s disease

IgG Albumin 59Fe

FCR** synthesis FCR * * synthesis QF*** Faecal % per day mdkdd % per day mg/kg/d clearance****

5 -9 16-57 7-1 I 136-241 .: 1 % i 0.8

21.8 11.8 11.3 15.5

20.7 28.2 14.1 18.6

12.9 13.5

149 41 54 84

226 318 75

I55

33 63

12.3 10.8 10.5

14.7 20.4 12.3 13.8

15.3 11.4

206 161 171

196 31 1 197 I86

258 142

4.5 6.4 2.9 I .6

7.7 6.8 6.1 5.1

5.3 3.3

4.8 5.2 3.1 1.9

5.9 1.3 5.1 6.4

6.7 5.1

*** QF=faecal excretion of s8Fe, per cent of injected dose, in 4-5 days. I * * * Faecal clearance: Daily faecal isotope excretion as per cent of the intravascular mass.

X - 1 . 4 6 ~ - 2.8, (1) where x=catabolic rate of IgG

y =catabolic rate of albumin

The regression coefficient is above unity, which is at variance with the generally held view that gastrointestinal protein loss is a ‘bulk loss’ (Waldmann & Schwab 1965). This im- plicates an identical loss rate of all plasma proteins and therefore a similar increase of catabolic rate irrespective of their molecular weight. Actually, in the present study it was found that patients with protein-losing entero- pathy due to intestinal lymphangiectasia fol- lowed another equation of regression (Fig. 2):

of albumin about 70000, IgG : about 160000). Evidence of a similar preferential gastro- intestinal loss of smaller macromolecules has been presented in the nephrotic syndrome by means of 1311-polyvinylpyrrolidone (Hazenberg 1968).

It is considered unlikely that the high cat- abolic rate in Crohn’s disease (equation ( I ) ) is due to a selective protein loss of IgG. We therefore conclude that this disease by an unknown mechanism brings about a stimula- tion of both catabolism and synthesis of IgG. In this respect one may draw a parallel to other chronic, inflammatory conditions like cirrhosis of the liver and systemic lupus ery-

x = 0 . 7 5 ~ + 2.2 (2) thematosus in which IgG metabolism is af- with a regression coefficient below unity. Thus, fected in much the Same way (Andersen 1964). the intestinal loss rate of albumin is probably The increase of IgG synthesis and the nor- higher than that of IgG in intestinal lym- mal serum concentrations of IgA and IgM phangiectasia. It means that, to some extent, (Table 11) indicate that, quantitatively, the a preferential loss of smaller protein molecules antibody-producing capacity of the immune proceeds in this condition (molecular weight apparatus is normal. The serum levels of the

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488 G. BENDIXEN, S. JARNUM, J. SBLTOFT, H. WESTERGAARD, B .WEEKE & MlNNA YSSING

3 main types of circulating, extracellular im- munoglobulins are consistent with the pre- sumption that the ability of the organism to develop and maintain a state of humoral hypersensitivity is intact.

Concerning cellular hypersensitivity in Crohn's disease, the present investigation is not very informative. Positive delayed-type intracutaneous reactions indicating cellular hypersensitivity to tuberculin were found in 6 of 8 petients examined (Table I), but this observation is inconclusive. The leucocyte migration test with intestinal mucosa com- pounds was normal in all cases, which conform to previous findings (Bendixen 1967). The absence of tissue-specific cellular hypersen- sitivity contrasts with the findings in ulcerative colitis, where the leucocyte migration test most often reveals a hypersensitivity of the cellular type. A similar autoimmune reactivity depend- ing on a cellular hypersensitivity mechanism with possible implications for the pathogenesis does not seem to exist in Crohn's disease.

The high distribution ratio of both albumin and IgG (Fig. 3) in Crohn's disease is difficult to explain. The same observation has been made in nephrotic children (Yssing, Jensen & Jarnum 1968) and for a plasma protein which is present in plasma in very low concentration due to a congenital deficiency of its synthesis, e.g. albumin in analbuminaemia (Bennhold & Kallee 1959). The abnormal distribution may reflect a decreased capillary permeability (which was not specifically studied in this se- ries) or an increased lymphatic flow. Further studies are needed to establish which mecha- nism is working.

The high faecal radioiodine excretion seen in patients with colonic involvement following intravenous injection of radioiodine labelled IgG and albumin seems to be a guide to a distal site of protein leakage (Westergaard, Jarnum, Jensen, Soltoft & Yssing 1968). In patients with terminal ileitis, the faecal excre- tion of radioiodine from labelled albumin was relatively low, whereas the faecal output of the label from IgG was proportionally much

higher. This might suggest a difference be- tween albumin and IgG resistance to proteo- lytic enzymes present in the small intestinal lumen. The difference observed may in fact point to the small intestine as the protein- leaking site. Investigations are now carried out to substantiate this supposition.

ACKNOWLEDGEMENTS

The highly skillful assistance of exam. pharm. Mrs. Bodil Moller Pedersen, who carried out all the protein labelling, is gratefully acknow- ledged.

This work was supported by grants from Christian den X s Fond, Statens Videnskabs- fond, P. Carl Petersens Fond and NOVO's Fond.

REFERENCES ANDERSEN, S. B. (1964) Metabolism of Human Gamma

Globulin (yss-globulin). Blackwell, Oxford. ANDERSEN, S. B. & JARNUM, S. (1966) Gastrointestinal protein loss measured with KDFe-labelled iron dextran. Lancet I, 1060-1062.

ANDERSEN, S. B., JARNUM, S., JENSEN, H. & ROSSING, N. (1968) Metabolism of yG-globulin in the nephrotic syndrome in adults. Scand. J. clin. Lab. Invest. 21,

BENDIXEN, G. (1967) Specific inhibition of the in vitro migration of leucocytes in ulcerative colitis and Crohn's disease. Scand. J . Gastroent. 2,214-221.

BENNHOLD, H. & KALLEE, E. (1959) Comparative studies on the half-life of 1131-labelled albumins and non-radioactive human serum albumin in a case of analbuminemia. J. clin. Invest. 38, 863-872.

HAZENBERG, B. P. (1968) pp. 85-96 in Gastrointestinale Serumeiwituitscheiding. Bronsema's Drukkerij, En- schede, Holland.

JARNUM, S. (1961) Faecal 1311-o~tp~t after intravenous injection of 1311-labelled human serum albumin in normo- and hypoproteinaemic subjects. Scand. J. clin. Lab. Invest. 13,462-475.

JARNUM, S. , WESTERGAARD, H., YSSING, M. & JENSEN, H. (1968) Quantitation of gastrointestinal protein loss by means of 68Fe-labelled iron dextran. Gastroentero-

PHEAR, D. N. (1958) The relation between regional

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I ~ ~ J J 55, 229-241.

ileitis and sarcoidosis. Lancet 11, 1250-1251.

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Igc AND ALBUMIN TURNOVER IN CROHN’S DISEASE 489

ROSSING, N. & JENSEN, H. (1967) Metabolic studies of different albumin preparations. Clin. Sci. 32, 89-99.

TAYLOR, K. B. (1965) Immune mechanisms in gastro- enterology. pp. 24-48 in Recent Advances in Gastro- enterology. Eds. BADENOCH and BROOKE. Churchill, London.

YSSING, M., JENSEN, H. & JARNUM, S. (1968) Albumin metabolism and gastrointestinal protein loss in children with nephrotic syndrome. Submitted for publication in Acta paediat. scand.

WALDMANN, T. A. & SCHWAB, P. J. (1965) IgG (7s y-globulin) metabolism in hypogammaglobulinemia.

Studies in patients with defective gamma globulin synthesis, gastrointestinal protein loss, or both. J. clin. Invest. 44, 1523-1533.

WEEKE, B. (1968) Carbamylated human imrnuno- globulins tested by electrophoresis in agarose and antibody containing agarose. Scand. J. clin. Lab. Invest., 21, 351-354.

J. & YSSING, M. (1968) Topographic diagnosis of gastrointestinal protein loss. Digestion. In Press.

WESTERGAARD, H., JARNUM, S., JENSEN, H., SBLTOn,

Received 12 June 1968 Accepted 20 July 1968

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