THROMBOSIS RESEARCH 67; 467471,1992 0049-3646192 $5.00 + .OOPrinted in the USA. Copyright (c) 1992 Pergamon Press Ltd. All rights reserved.
ERIEF
THE
COI"LJ!'lUNICATION
RESPONSE OF PLASMA VON WILLEBRAND FACTOR TO DESMOPRESSIN (DDAV~) IS RELATED TO THg PLATELET LEVELS OF VON WILLEBRAND FACTOR A. Lattuada,
P. Varanukulsak,
G.C. Castaman,
P.M. Maunucci
Angelo Bianchi Bonomi Hemophilia and Thrombosis Center and Institute of Internal Medicine, IRCCS Maggiore Hospital and University of Milan; and the Hemophilia and Thrombosis Center, Hematology Division, Vicenza, Italy (Received 20.4.1992; accepted in original form 4.6.1992 by Editor G.G. Neri Serneri) (Received by Executive Editorial Office 13.7.1992)
The administration of desmopressin (1-deamino-8-D-arginine vasopressin, DDAVP) is followed by a marked increase in the plasma levels of von Willebrand factor (vWF) (1). Such increase, to approximately 3-4 times the pre-DDAVP values, occurs in healthy individuals and in the majority of patients with von Willebrand disease (vWD) (2,3). Since vWF is synthesized and stored in vascular endothelial cells, DDAVP is thought to act by releasing vWF from endothelial cells into plasma (4). Being obviously difficult to measure vWF in endothelial cells of vWD patients, the hypothesis that the increase of vWF after DDAVP is proportional to the vWF content of endothelial cells cannot be directly evaluated. vWF, however, can be measured in platelets, other vWFcontaining cells. Platelet vWF might reflect endothelial vWF and predict the degree of vWF response to DDAVP. This hypothesis is supported by the observation that homozygous patients with severe (type III) vWD, who have very low or unmeasurable vWF in both endothelial cells and platelets, are unresponsive to DDAVP (2); and that patients with type I vWD, with low platelet vWF (subtype "platelet low"), respond poorly (5). To further evaluate the hypothesis of a direct relationship between platelet vWF levels and plasma vWF increase after DDAVP, Key words: desmopressin, Willebrand disease
DDAVP, 467
von Willebrand
factor,
von
DDAVP AND PLATELET VW FACTOR
468
Vol. 67, No. 4
we elected to study a natural model represented by obligatory heterozygotes for severe vWD. Some of these asymptomatic individuals, parents or children of homozygous patients, have low vWF levels in plasma contrasting with normal levels in platelets (phenotype: plasma low-platelet normal), whereas others have normal levels in plasma and low levels in platelets (phenotype: plasma normal-nlatelet low) (6). We reason that, if the vWF content of endothelial cells is proportional to that of platelets, heterozygotes with low platelet vWF should respond less to DDAVP than those with normal levels.
=TERIALS
ARD MRTRODS
Four heterozygotes with the plasma low-nlatelet normal phenotype and three with the plasma normal-nlatelet low phenotype were enrolled in the study after its experimental purpose was explained and informed consent obtained. These individuals belong to kindreds including at least one patient affected by severe (type III) vWD (6). Their plasma and platelet vWF levels are given in Table I.
T&l8
I:
Plasm with
Probmd
and
platelet
severe
van
van
Willabrand
Willebrand
factor
Heterozygote (rslation
to
in
obligatory
heterorygotes
relatives
of
patients
disease
Plasma
proband)
vWF
Platelet
(U/dL)
..
(U/a
vWF
vWF Phenotype ~DlSS”%S/DlStSlSt~
protein1
vWF:Aa
Ricof
vWF:Aa
Ricof
B.G.B.
father
73
68
42
48
normal-low
8.0.
mther
110
a3
?1
22
normal-low
Z.R.
father
66
61
43
38
norMl-low
C.E.
father
32
so
75
70
low-norms1
E.G.
father
s
26
07
72
low-norms1
P.M.
mother
41
,1
121
87
low-mnnsl
P.M.
father
38
ZJ
80
81
low-nmmsl
56-203
53-146
67-132
Normal
Values
underlined
ranges
are
abtxwmslly
low,
i.e.,
bslow
the
5th
percentile
63-130
of
the
norms1
range.
DDAVP (0.3 pg/kg) was infused over 30 min in 100 ml of saline. Citrated blood samples (0.129 M) were obtained before starting the infusion, at the end of the infusion (at 30 min) and then at 60, 120 and 240 min. Plasma vWF antiaen (vWF:Ag) was measured in these samples electroimmunoassay and ristocetin cofactor activity (Ricof) with a method based on aggregometry of formalin-fixed platelets (5).
Vol. 67, No. 4
DDAVP AND PLATELET VW FACTOR
469
To compensate for differences in plasma values of these measurements, results were normalized by expressing post-DDAVP values in percentage increase over pre-DDAVP values.
500-
400 -
300 -
200-
ioo-
0
30 60 120 Time after starting DDAVP (min)
240
1. Changes of von Willebrand factor antigen in heterozygotes of severe von Willebrand disease with the plasma normal- nlatelet low phenotype (solid lines) as compared with those with the plas a 1 w) phenotype (broken lines). Values are expressed in percent of baseline values. FIGURE
5004
0
i0 $0 li0 Time after starting DDAVP (min)
2;10
FIGURE 2. Changes of ristocetin cofactor activity (see Fig. 1).
470
DDAVP AND PLATELET VW FACTOR
Vol. 67, No. 4
RESULT@
Fiaure 1 shows that in heterozygotes with normal levels of platelet vWF (plasma low-nlatelet normal) plasma vWF:Ag increased markedly after DDAVP, peaking at 60 min and reaching values 3.5 to 4.5 times higher than baseline values. In heterozygotes with low levels of platelet vWF (plasma normalplatelet low), plasma vWF:Ag increased much less, to approximately 1.5-2.5 times over baseline values, with peak levels reached at 120 min after DDAVP. Fiuure 2.shows that Ricof behaved similarly to vWF:Ag.
DISCUSSION
Although no statistical analysis was performed because of the small size of the sample, the post-DDAVP behaviour of plasma vWF was clearly different, both quantitatively and qualitatively, in heterozygotes with low levels of platelet vWF compared with those with normal levels. On average, the rise of plasma vWF was much smaller in patients with low platelet vWF, indicating that the plasma vWF response to DDAVP is proportional to platelet vWF levels. There were also more subtle qualitative differences in the behaviour of the two groups. In heterozygotes with the plasma peaked at 60 min low- platelet normal phenotype, vWF postinfusion and declined subsequently, as it occurs in normal individuals (1). In those with the plasma normal- platelet low phenotype, there was a slowly progressive increase of vWF which peaked later. There is no clear explanation for this different behaviour. By no means our data should be taken as evidence that platelets are the source of vWF released by DDAVP. Evidence against this stems from the observation that patients with severe amegakaryocytic thrombocytopenia and reduced platelet mass respond fully to DDAVP in terms of vWF increase (7). On the other hand, our data indicate that the platelet vWF content can be taken as an indirect index of the vWF content in endothelial cells.
ACXWOWLEDGEHEI'JTS
This work was supported in part by CNR, Progetto Finalizzato Ingegneria Genetica, and National Institutes of Health, grant HL41135.
Vol. 67, No. 4
DDAVP AND PLATELET VW FACTOR
471
REFERENCES 1. MANNUCCI, P.M., ALBERG, M., NILSSON, I.M. and ROBERTSON, B.
Mechanism of plasminogen activator and factor VIII increase after vasoactive drugs. Br J Haematol 30, 81-93, 1975. 2. MANNUCCI, P.M., PARETI, F.I., HOLMBERG, L., RUGGERI, Z.M. and NILSSON, I.M. Studies on the prolonged bleeding time in von Willebrand disease. J Lab Clin Med 88, 662-669, 1976. 3. MANNUCCI, P.M., CANCIANI, M.T., ROTA, L. and DONOVAN, B.S. Response of factor VIII/van Willebrand factor to DDAVP in healthy subjects and patients with hemophilia A and von Willebrand's disease. Br J Haematol 47, 283-293, 1981. 4. TAEEUCHI, M., NAGUZA, H. and KANEDU, T. DDAVP and eoineDhrine induced changes in the localization of von Willebrkd factor antigen in endothelial cells of human oral mucosa. Blood 72, 850-854, 1988. MANNUCCI, P.M., LOMBARDI, R., BADER, R., VIANELLO, L., FEDERICI, A.B., SOLINAS, S., MAZZUCCONI, M.G. and MARIANI, G. Heterogeneity of type I von Willebrand disease: evidence for a subgroup with an abnormal von Willebrand factor. Blood 66, 796-802, 1985. MANNUCCI, P.M., LATTUADA, A., CASTAMAN, G., LOMBARDI, R., COLIBRETTI, M.L., CIAVARELLA, N. and RODEGHIERO, F. Heterogenous phenotypes of platelet and plasma von Willebrand factor in obligatory heterozygotes for severe von Willebrand disease. a, B 2433-2436, 1989. MANNUCCI, P.M., VICENTE, V., VIANELLO, L., CATTANEO, M., ALBERCA, I., COCCATO, M.C., FAIONI, E. and MARI, D. Controlled trial of desmopressin (DDAVP) in liver cirrhosis and other conditions associated with a prolonged bleeding time. Blood 67, 1148-1153, 1986.
ERIEF
THE
COI"LJ!'lUNICATION
RESPONSE OF PLASMA VON WILLEBRAND FACTOR TO DESMOPRESSIN (DDAV~) IS RELATED TO THg PLATELET LEVELS OF VON WILLEBRAND FACTOR A. Lattuada,
P. Varanukulsak,
G.C. Castaman,
P.M. Maunucci
Angelo Bianchi Bonomi Hemophilia and Thrombosis Center and Institute of Internal Medicine, IRCCS Maggiore Hospital and University of Milan; and the Hemophilia and Thrombosis Center, Hematology Division, Vicenza, Italy (Received 20.4.1992; accepted in original form 4.6.1992 by Editor G.G. Neri Serneri) (Received by Executive Editorial Office 13.7.1992)
The administration of desmopressin (1-deamino-8-D-arginine vasopressin, DDAVP) is followed by a marked increase in the plasma levels of von Willebrand factor (vWF) (1). Such increase, to approximately 3-4 times the pre-DDAVP values, occurs in healthy individuals and in the majority of patients with von Willebrand disease (vWD) (2,3). Since vWF is synthesized and stored in vascular endothelial cells, DDAVP is thought to act by releasing vWF from endothelial cells into plasma (4). Being obviously difficult to measure vWF in endothelial cells of vWD patients, the hypothesis that the increase of vWF after DDAVP is proportional to the vWF content of endothelial cells cannot be directly evaluated. vWF, however, can be measured in platelets, other vWFcontaining cells. Platelet vWF might reflect endothelial vWF and predict the degree of vWF response to DDAVP. This hypothesis is supported by the observation that homozygous patients with severe (type III) vWD, who have very low or unmeasurable vWF in both endothelial cells and platelets, are unresponsive to DDAVP (2); and that patients with type I vWD, with low platelet vWF (subtype "platelet low"), respond poorly (5). To further evaluate the hypothesis of a direct relationship between platelet vWF levels and plasma vWF increase after DDAVP, Key words: desmopressin, Willebrand disease
DDAVP, 467
von Willebrand
factor,
von
DDAVP AND PLATELET VW FACTOR
468
Vol. 67, No. 4
we elected to study a natural model represented by obligatory heterozygotes for severe vWD. Some of these asymptomatic individuals, parents or children of homozygous patients, have low vWF levels in plasma contrasting with normal levels in platelets (phenotype: plasma low-platelet normal), whereas others have normal levels in plasma and low levels in platelets (phenotype: plasma normal-nlatelet low) (6). We reason that, if the vWF content of endothelial cells is proportional to that of platelets, heterozygotes with low platelet vWF should respond less to DDAVP than those with normal levels.
=TERIALS
ARD MRTRODS
Four heterozygotes with the plasma low-nlatelet normal phenotype and three with the plasma normal-nlatelet low phenotype were enrolled in the study after its experimental purpose was explained and informed consent obtained. These individuals belong to kindreds including at least one patient affected by severe (type III) vWD (6). Their plasma and platelet vWF levels are given in Table I.
T&l8
I:
Plasm with
Probmd
and
platelet
severe
van
van
Willabrand
Willebrand
factor
Heterozygote (rslation
to
in
obligatory
heterorygotes
relatives
of
patients
disease
Plasma
proband)
vWF
Platelet
(U/dL)
..
(U/a
vWF
vWF Phenotype ~DlSS”%S/DlStSlSt~
protein1
vWF:Aa
Ricof
vWF:Aa
Ricof
B.G.B.
father
73
68
42
48
normal-low
8.0.
mther
110
a3
?1
22
normal-low
Z.R.
father
66
61
43
38
norMl-low
C.E.
father
32
so
75
70
low-norms1
E.G.
father
s
26
07
72
low-norms1
P.M.
mother
41
,1
121
87
low-mnnsl
P.M.
father
38
ZJ
80
81
low-nmmsl
56-203
53-146
67-132
Normal
Values
underlined
ranges
are
abtxwmslly
low,
i.e.,
bslow
the
5th
percentile
63-130
of
the
norms1
range.
DDAVP (0.3 pg/kg) was infused over 30 min in 100 ml of saline. Citrated blood samples (0.129 M) were obtained before starting the infusion, at the end of the infusion (at 30 min) and then at 60, 120 and 240 min. Plasma vWF antiaen (vWF:Ag) was measured in these samples electroimmunoassay and ristocetin cofactor activity (Ricof) with a method based on aggregometry of formalin-fixed platelets (5).
Vol. 67, No. 4
DDAVP AND PLATELET VW FACTOR
469
To compensate for differences in plasma values of these measurements, results were normalized by expressing post-DDAVP values in percentage increase over pre-DDAVP values.
500-
400 -
300 -
200-
ioo-
0
30 60 120 Time after starting DDAVP (min)
240
1. Changes of von Willebrand factor antigen in heterozygotes of severe von Willebrand disease with the plasma normal- nlatelet low phenotype (solid lines) as compared with those with the plas a 1 w) phenotype (broken lines). Values are expressed in percent of baseline values. FIGURE
5004
0
i0 $0 li0 Time after starting DDAVP (min)
2;10
FIGURE 2. Changes of ristocetin cofactor activity (see Fig. 1).
470
DDAVP AND PLATELET VW FACTOR
Vol. 67, No. 4
RESULT@
Fiaure 1 shows that in heterozygotes with normal levels of platelet vWF (plasma low-nlatelet normal) plasma vWF:Ag increased markedly after DDAVP, peaking at 60 min and reaching values 3.5 to 4.5 times higher than baseline values. In heterozygotes with low levels of platelet vWF (plasma normalplatelet low), plasma vWF:Ag increased much less, to approximately 1.5-2.5 times over baseline values, with peak levels reached at 120 min after DDAVP. Fiuure 2.shows that Ricof behaved similarly to vWF:Ag.
DISCUSSION
Although no statistical analysis was performed because of the small size of the sample, the post-DDAVP behaviour of plasma vWF was clearly different, both quantitatively and qualitatively, in heterozygotes with low levels of platelet vWF compared with those with normal levels. On average, the rise of plasma vWF was much smaller in patients with low platelet vWF, indicating that the plasma vWF response to DDAVP is proportional to platelet vWF levels. There were also more subtle qualitative differences in the behaviour of the two groups. In heterozygotes with the plasma peaked at 60 min low- platelet normal phenotype, vWF postinfusion and declined subsequently, as it occurs in normal individuals (1). In those with the plasma normal- platelet low phenotype, there was a slowly progressive increase of vWF which peaked later. There is no clear explanation for this different behaviour. By no means our data should be taken as evidence that platelets are the source of vWF released by DDAVP. Evidence against this stems from the observation that patients with severe amegakaryocytic thrombocytopenia and reduced platelet mass respond fully to DDAVP in terms of vWF increase (7). On the other hand, our data indicate that the platelet vWF content can be taken as an indirect index of the vWF content in endothelial cells.
ACXWOWLEDGEHEI'JTS
This work was supported in part by CNR, Progetto Finalizzato Ingegneria Genetica, and National Institutes of Health, grant HL41135.
Vol. 67, No. 4
DDAVP AND PLATELET VW FACTOR
471
REFERENCES 1. MANNUCCI, P.M., ALBERG, M., NILSSON, I.M. and ROBERTSON, B.
Mechanism of plasminogen activator and factor VIII increase after vasoactive drugs. Br J Haematol 30, 81-93, 1975. 2. MANNUCCI, P.M., PARETI, F.I., HOLMBERG, L., RUGGERI, Z.M. and NILSSON, I.M. Studies on the prolonged bleeding time in von Willebrand disease. J Lab Clin Med 88, 662-669, 1976. 3. MANNUCCI, P.M., CANCIANI, M.T., ROTA, L. and DONOVAN, B.S. Response of factor VIII/van Willebrand factor to DDAVP in healthy subjects and patients with hemophilia A and von Willebrand's disease. Br J Haematol 47, 283-293, 1981. 4. TAEEUCHI, M., NAGUZA, H. and KANEDU, T. DDAVP and eoineDhrine induced changes in the localization of von Willebrkd factor antigen in endothelial cells of human oral mucosa. Blood 72, 850-854, 1988. MANNUCCI, P.M., LOMBARDI, R., BADER, R., VIANELLO, L., FEDERICI, A.B., SOLINAS, S., MAZZUCCONI, M.G. and MARIANI, G. Heterogeneity of type I von Willebrand disease: evidence for a subgroup with an abnormal von Willebrand factor. Blood 66, 796-802, 1985. MANNUCCI, P.M., LATTUADA, A., CASTAMAN, G., LOMBARDI, R., COLIBRETTI, M.L., CIAVARELLA, N. and RODEGHIERO, F. Heterogenous phenotypes of platelet and plasma von Willebrand factor in obligatory heterozygotes for severe von Willebrand disease. a, B 2433-2436, 1989. MANNUCCI, P.M., VICENTE, V., VIANELLO, L., CATTANEO, M., ALBERCA, I., COCCATO, M.C., FAIONI, E. and MARI, D. Controlled trial of desmopressin (DDAVP) in liver cirrhosis and other conditions associated with a prolonged bleeding time. Blood 67, 1148-1153, 1986.
