Scandinavian Journal of Clinical and Laboratory Investigation

ISSN: 0036-5513 (Print) 1502-7686 (Online) Journal homepage: http://www.tandfonline.com/loi/iclb20

Variations in Plasma Protein Concentrations in Individuals with Ulcerative Colitis: Analytical and Biological Factors Henrik Nielsen, Per Hyltoft Petersen, Ulla Feldt-Rasmussen & Vibeke Binder To cite this article: Henrik Nielsen, Per Hyltoft Petersen, Ulla Feldt-Rasmussen & Vibeke Binder (1979) Variations in Plasma Protein Concentrations in Individuals with Ulcerative Colitis: Analytical and Biological Factors, Scandinavian Journal of Clinical and Laboratory Investigation, 39:6, 495-502, DOI: 10.1080/00365517909108826 To link to this article: http://dx.doi.org/10.1080/00365517909108826

Published online: 14 Feb 2011.

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Date: 27 June 2016, At: 13:01

Scand. J. clin. Lab. Invest. 39, 495-502, 1979.

Variations in plasma protein concentrations in individuals with ulcerative colitis: analytical and biological factors

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H E N R I K NI ELS E N , ' P E R H Y L T O F T P E T E R S E N , Z U L L A F ELDT- R A SMU SSE N ' & V I B E K E B I N D E R 3 Institute of Medical Microbiology, Odense University, Department of Clinical Chemistry, Odense University Hospital and Department of Medical Gastroenterology, Herlev University University Hospital, Denmark.

Nielsen, H., Petersen, P.H., FeIdt-Rasmussen, U. & Binder V. Variations in plasma protein concentrations in individuals with ulcerative colitis: analytical and biological factors. Scand. J. clin. Lab. Invest. 39, 495-502, 1979. Eight plasma proteins were determined in specimens taken every second day during a 14 day period from eleven patients with acute ulcerative colitis. The intra-individual variations in the concentrations of albumin, orosomucoid, haptoglobin, IgG, IgA, IgM and complement factors C3 and C4 were larger than expected in normal persons. A two-way analysis of variance was applied to the normalized protein values to estimate to what extent the observed variations could be explained by analytical errors and the influence of biological factors general to all proteins, such as changes in plasma volume and distribution between plasma and extravascular space. In half the non-operated patients the changes in all proteins could be explained by the above mentioned variations. The individual variations seen in the concentrations of haptoglobin, C4 and IgM occurred at randomcompared to the clinical state of the disease. Only the operated patients showed a more systematic sequence of protein changes. Key-words: albumin, acute phase proteins, complement factors, immunoglobulins; intra-individual variation, analytical error, biological variation Henrik Nielsen, M.D., Institute of Medical Microbiology, Odense University, 5000 Odense C, Denmark.

A number of plasma proteins show concentration changes during various states of disease. A fast rise in acute phase proteins during trauma is the most marked [16]. In chronic diseases, such as ulcerative colitis, concentrations of selected plasma proteins have been correlated to the disease activity [4, 7, 111. The mechanisms by which these changes in concentrations occur are specific for individual proteins, e.g. secretion rate (rate of synthesis) 0036-5513/79/ 1000-0495$02.00 01979 Medisinsk Fysiologisk Forenings Forlag

and/or catabolic rate [2, 3, 5, 81. Furthermore, factors general to all proteins such as plasma volume and the distribution of protein between plasma and extravascular space [9, 12, 161 play a major role for the actual protein concentration in plasma. Other factors contributing to the general variations are posture and the tourniquet used while drawing the blood [13]. Finally, the analytical variation will influence the single measurement of the plasma protein concentration [14, 151. In the present paper measurements of eight 495

496

H. Nielsen et al.

plasma proteins were performed in eleven patients with ulcerative colitis during a 14 day period of treatment. The aim of this study was to determine to what extent influence of the above mentioned general factors could explain the observed changes in the specific plasma protein concentrations.

MATERIAL A N D METHODS

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Material The source of test materials consisted of eleven ward patients (seven men, four women) with ulcerative colitis: Of these, four were characterized as moderate and seven as severe cases at the start of the investigation i.e. more than four bowel movements a day (moderate) and besides that fever and generally affected state (severe). Two of the severe cases were operated on within the period of investigation. The investigation was carried out during the first 14 days after admission of the patients to the medical department. All patients improved clinically, during the observation period, either on medical or on surgical treatment. A more detailed description of the patients was given in a previous paper on immune complex detection in serum of patients with ulcerative colitis [lo]. Blood was drawn in the morning. The patients were supine and the specimens were collected in glass tubes without any anticoagulant using only a slight tourniquet. Centrifugation was carried out within 1-2 h after collection and serum was separated immediately and then stored at - 60°C until assay.

Methods Analytical methods. Serum concentrations of albumin (Alb), orosomucoid (Oros), haptoglobin (Hp) and the complement factor C4 (C4) were determined by electroimmunoassay as described by Laurel1 [6]. Immunoglobulins IgG (IgG), IgA (IgA) and IgM (IgM) were determined by electroimmunoassay subsequent to carbamylation with cyanate as described by Weeke 1171. The complement factor C3 (C3) was determined by electroimmunoassay after treatment with zymosan as previously described [l 11.

Analytical variation. Based on serum protein determinations of a control serum on 20 independent days the following analytical coefficients of variation CVA, =

J" o2 a

for all assays were calculated: Alb: CVA = 0.03, Hp:CVA = 0.06, Oros: CVA = 0.05 IgG : CVA = 0.04, IgA: IgA = 0.06, IgM : CVn = 0.08 C 3: CVA = 0.06, C 4: CVA = 0.06

r-

Pooled analytical variation PCVAwas calculated

c

by the formula PCVA =

i = l

cv:,

m for each combination of m proteins.

Mathematical model. Because of large differences between the concentrations of the individual proteins (Table I) it was necessary to normalize these concentrations for the purpose of comparing the variations within the individual patient. Normalization within the individual patient was undertaken by dividing each measured protein concentration by the mean of all the measured concentrations for the same protein (Xi) in the patient. By this procedure the fractional concentrations: Xljh Yllh = - for each of the m proteins were

2,

obtained and the variations in all proteins were thereby given the same weight. Each individual observation of a fractional plasma protein concentration ( Y i j h ) in a single patient was potentially the sum of five separable terms [l]: Yllh

= fl + g I

+ tJ

+(@)I)

+ elJh

where p was the mean of the m individual fractional protein means, g , was the deviation from p of the mean of the fractional concentrations of each individual protein (i), t j was the deviation from u, of the mean of the fractional protein concentrations of t h e m proteins on each individual day (j),(gt)lJmeasured the interaction of proteins by days and ellh was the random error peculiar to each observation. By definition ~1 was equal to one, and all

HH EA PB* SM*

SS

BM JK

PK

PS

VB TM

Patient

7 6 5 5 5 5 7

7 6 7 6

0.04 0.05 0.09 0.06

CV

28.9 0.07 26.2 0.13 22.6 0.10 33.5 0.02 35.9 0.08 24.3 0.13 28.6 0.22 36-46

38.0 25.3 36.5 34.8

(g/l)

* Patient operated during the observation period.

Reference values

Severe

Moderate

Disease activity

No. of specimens n

Alb.

0.14

0.05

0.39 0.20

CV

5.42 0.12 3.93 0.05 4.82 0.10 6.19 0.06 1.13 0.18 5.22 0.17 4.96 0.11 0.29-2.80

0.86 3.57 4.91 1.50

(g/l)

HP

0.15 0.12 0.06 0.06

2.79 0.11 1.95 0.08 2.58 0.13 3.09 0.03 1.12 0.14 4.32 0.13 3.29 0.12 0.62-1.42

1.08 2.73 1.90 1.38

(A.U) CV

Oros

0.06 0.12 0.10 0.07

CV 0.06 0.10 0.17 0.09

0.96 0.15 0.47 0.12 0.26 0.09 0.49 0.13 0.36 0.04 0.90 0.80 0.58 0,55 0.18-1.30

1.09 0.39 0.37 0.24

CV

kM (g/l)

Protein

1.38 0.10 1.66 0.09 1.41 0.09 0.75 0.04 1.08 0.07 1.53 0.30 1.67 0.20 0.40-3.43

1.00 0.97 1.77 0.80

(g/l)

IgA

0.03 0.09 0.06 0.06

CV

11.4 0.07 11.6 0.08 13.1 0.07 13.3 0.06 10.5 0.06 8.5 0.21 13.6 0.19 6.2-13.3

10.2 7.8 13.3 9.8

(g/l)

IgG

0.06 0.15 0.09 0.15

CV

2.00 0.15 1.60 0.07 1.96 0.04 2.19 0.08 1.15 0.03 1.73 0.15 2.06 0.13 0.72-1.68

1.27 1.40 1.16 1.14

(g/l)

c3

TABLE I. Mean values and coefficients of variation for eight plasma protein concentrations in eleven patients with ulcerative colitis during a 14 day period

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0.12 0.30 0.10 0.17

CV

0.62 0.25 0.51 0.10 0.70 0.08 0.69 0.09 0.37 0.09 0.44 0.34 0.53 0.22 0.18-0.85

0.33 0.56 0.43 0.36

(g/l)

c4

9'

~

498

H. Nielsen et al. TABLE 11. Estimated components of between-day-variation (CVs) and interaction (CV,) for eight proteins in eleven patients with ulcerative colitis during a 14 day period Between-day-variation Disease activity

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Moderate

Patient

F-value

V.B. T.M. P.S.

4.34** 4.85** 13.20** 6.56** P.K. 8.68** Severe B.M. 3.45* J.K. 15.04** S.S. 0.75 H.H. 1.15 E.A. 2.12 P.R.t 6.51** S.M.t Mean (operated patients not included)

Estimated CVB 0.08

0.09 0.08 0.07 0.10 0.04 0.7 -0 0.01

0.12 0.16 0.06

Interaction F-value$ 4.81** 4.67** 1.03 1.91 2.76** 1.75 0.84 1.29 2.67* 29.37** 10.64**

Estimated CV1 0.12 0.11 0.01 0.06 0.08 0.05 -0 0.03 0.08 0.32 0.19 0.06

t Patients operated during the observation period.

2 The significance was

based on 19 DF of PCV, (see methods).

PCVA = 0.06. * P