D. Blockmans - Academia.edu (original) (raw)
Papers by D. Blockmans
Anamnese en lichamelijk onderzoek, 2016
Nederlands tijdschrift voor geneeskunde, Jan 29, 2003
Two patients, a woman aged 66 and a man aged 56 years, with an inflammatory syndrome, weight loss... more Two patients, a woman aged 66 and a man aged 56 years, with an inflammatory syndrome, weight loss, joint pain and abdominal lymphadenopathy received long-term treatment with corticosteroids for alleged sarcoidosis. No long-term remission was induced and the patients were referred for a second opinion. Eventually the diagnosis of Whipple's disease was established 5 years after the appearance of the first symptoms in the case of the female patient and 4 years after in the case of the male patient. Both patients showed a marked clinical improvement after treatment with trimethoprim-sulfamethoxazole. An atypical presentation of alleged sarcoidosis should suggest the possibility of Whipple's disease, especially in the case of gastrointestinal symptoms and the failure to respond to corticosteroids, and warrants duodenal biopsy. The presence of granulomas with an elevated angiotensin-converting enzyme level is not pathognomonic for sarcoidosis. It is vitally important to distinguis...
Acta clinica Belgica, Jan 6, 2015
Background: Polyarteritis nodosa (PAN) is a rare form of systemic vasculitis, characterized by ne... more Background: Polyarteritis nodosa (PAN) is a rare form of systemic vasculitis, characterized by necrotizing inflammation of medium-sized vessels. In clinical practice, the distinction is made between a limited, mostly cutaneous, form and a generalized form. The Chapel Hill Consensus Conference of 2012 on the classification of the vasculitides classifies PAN as a medium vessel vasculitis, whereas the limited forms fall under the heading 'single-organ vasculitis' (SOV), with subdivions such as 'cutaneous arteritis' (formerly called cutaneous PAN) and 'others'. In this last category, forms of PAN limited to a single organ (e.g. testicle, gall bladder or appendix) should be categorized. The relation between classical and limited forms of PAN remains enigmatic. Objective: To compare demographics, clinical characteristics and prognosis between SOV and generalized PAN. Methods: Clinical files of all patients with a diagnosis of classical or limited PAN made in the de...
Platelets, 1996
There is controversy in the literature regarding the effects of plasmin on human platelets. We ha... more There is controversy in the literature regarding the effects of plasmin on human platelets. We have studied the effects of plasmin on platelet glycoproteins, aggregation, shape change and secretion and found them to be dependent on experimental conditions: (a) Plasmin's effects on human platelets are only seen in gel-filtered platelets (GFP), presumably because in platelet rich plasma plasmin is bound to a2-antiplasmin; (b) in GFP to which fibrinogen has been added, platelet function remains intact; and (c) in the absence of fibrinogen, the effect of plasmin on GFP depends on whether stirring is performed or not. With stirring, platelets undergo shape change, secretion and aggregation in response to added plasmin. Aggregation is much stronger when CaCl(z) 1 mM is added. Without stirring, preincubation of GFP with plasmin leads to inhibition of platelet aggregation induced by subsequent platelet stimuli (thrombin, collagen, ristocetin or U46619). We have demonstrated that plasmin is a true platelet activating agent, in the sense that it induces platelet shape change and secretion. Plasmin will induce aggregation when added to stirred GFP. This may be because stirring protects glycoprotein (GP) IIbIIIa bound fibrinogen from being degradated by plasmin. When added to unstirred GFP, GP IIbIIIa bound fibrinogen may be readily accessible to degradation by plasmin, which may then behave like a platelet inhibitor.
Pediatric Transplantation, 2006
Journal of Clinical Immunology, 1984
European Radiology, 2004
Accepted: 7 July 2003 Published online: 21 October 2003 © Springer-Verlag 2003 Sir, Increased upt... more Accepted: 7 July 2003 Published online: 21 October 2003 © Springer-Verlag 2003 Sir, Increased uptake of F-18 fluorodeoxyglucose (FDG) in the aortic arch and its proximal branches suggests large vessel vasculitis [1, 2]. The differential diagnosis of Takayasu arteritis and temporal arteritis may be difficult. The 5 patients described by Meller et al. (3 women and 2 men; median age 60 years, age range 56–72 years) [3] have the typical characteristics of temporal arteritis and not those of Takayasu arteritis. These two large-vessel vasculitides are most clearly distinguished by the criterion of age and other epidemiological and clinical features [4, 5]. Approximately 90% of patients with Takayasu arteritis are less than 40 years of age, in contrast to those with temporal arteritis who tend to be older than 50 years. Takayasu arteritis is more common in Asians than in other racial groups. In contrast, temporal arteritis is most common in northern Europeans. The patients presented by Meller et al. presented with fever and other non-specific symptoms. Systemic symptoms occur in less than 30% of cases of Takayasu arteritis but are prevalent in patients with temporal arteritis [5]. Case series of patients with fever of unknown origin from western countries only occasionally include Takayasu arteritis, whereas temporal arteritis is the most frequent diagnosis in elderly patients (65 years of age or older) with fever of unknown origin [6]. Meller et al. performed Doppler ultrasonography of the temporal arteries. The contribution of this technique to the diagnosis of temporal arteritis is controversial. A recent study reported a sensitivity of only 40% [7]. Moreover, temporal artery involvement is not obligatory in temporal arteritis. In fact, one study reported negative temporal artery biopsy findings in 42% of patients with temporal arteritis presenting with large-vessel disease [8]. Our group and others have shown that FDG PET can be used to visualize inflammation of the aorta and its major branches in temporal arteritis [1, 2], yielding images very similar to the ones obtained in the patients described by Meller et al. [3]. Clinicians who are aware of the value of FDG PET in temporal arteritis will favor a diagnosis of temporal arteritis, not of Takayasu arteritis, in the patients presented by Meller et al. [3]. This distinction is important from the standpoint of potential complications and treatment options.
Clinical Rheumatology, 2001
Patients with systemic vasculitis represent an enormous diagnostic and therapeutic challenge for ... more Patients with systemic vasculitis represent an enormous diagnostic and therapeutic challenge for the medical profession. Diagnosis can be extremely difficult if presentation is atypical, without skin lesions or frank glomerulonephritis. Treatment consists mainly of steroids, either alone or in combination with cyclophosphamide, azathioprine, methotrexate or cyclosporine, depending on the exact type of vasculitis and the organs involved. For Kawasaki disease, intravenous immunoglobulins are the first choice. For hepatitis B-associated polyarteritis nodosa, Guillevin et al. [1] have demonstrated the effectiveness of a combination of an antiviral drug (interferon or vidarabine), plasma exchange and steroids. The rarity of these disorders does not allow every internist to gain enough experience in diagnosing and treating these patients properly. The patient described by Deléaval et al. in this issue (p. 291) did not get the stateof-the-art treatment initially. The exact diagnosis was made but the initial treatment with interferon alone was inadequate to treat this form of polyarteritis with neural involvement. Steroids (and plasma exchanges or lamivudine?) were indispensible here [2]. Fortunately, after starting the proper treatment the patient made a nearly full recovery. These are mistakes we all make from time to time. It is to the authors’ credit that they share this experience with us: we learn more from our mistakes than from the things we do right. Moreover, the field of vasculitis is evolving rapidly: great efforts are currently being made to optimise the treatment of the vasculitides. The current available therapy for severe systemic vasculitis indeed is not ideal. Immunosuppression has its price, especially in terms of infectious or neoplastic complications. The exact duration or mode of therapy is often not known. All these aspects are looked for in international multicentre studies. Because of the rarity of the vasculitides (with the exception of giant cell arteritis, which is rather common in an elderly population), no single investigator can gather enough patients to start a one-centre study. Under the auspices of the European Commission (BIOMED 1 and BIOMED 2 programs), the European Union Systemic Vasculitis Study Group (EUVAS) has started several studies comparing different types, modes and durations of treatment [3]. Researchers from the United Kingdom, Denmark, the Netherlands, Germany, France, Spain, Italy, Sweden, Greece and Belgium are involved. Project leader is Dr Niels Rasmussen from Copenhagen, trials administration is in the hands of Dr David Jayne, co-project leader, from London. They have ended the enrolment of patients into the CYCAZAREM-study (azathioprine is as good as cyclophosphamide during remission in ANCA-positive systemic vasculitis) and the NORAM-study (methotrexate versus cyclophosphamide in the treatment of non-renal Wegener’s granulomatosis). The following studies are currently under way:
Clinical Rheumatology, 2000
We describe here a patient with abdominal periaortitis and intramural dissection as early manifes... more We describe here a patient with abdominal periaortitis and intramural dissection as early manifestations of Wegener's granulomatosis (WG). Surgical biopsies taken from the retroperitoneal inflammatory tissue surrounding the aorta showed granulomatous vasculitis. The patient had antiproteinase-3 antibodies and suffered from nasal, pulmonary, nervous and renal WG involvement. Although being a vasculitis of medium size and small vessels, WG should be included in the systemic vasculitides which can give rise to (peri)aortic inflammation.
Clinical Rheumatology, 2004
Clinical Rheumatology, 1999
We describe three patients with histologically proven giant cell arteritis who presented with res... more We describe three patients with histologically proven giant cell arteritis who presented with respiratory complaints. In one patient, dry cough and dyspnoea dominated the clinical picture. In the other two patients, a diagnosis of giant cell arteritis was readily suspected by the presence of typical complaints, although both patients spontaneously mentioned a persistent cough and dyspnoea, respectively. Radiographs of the chest were normal. Lung function tests, including a carbon monoxide (CO)-diffusion capacity measurement, were always normal. Broncho-alveolar lavage fluid examination showed a normal cell count but an increased number of lymphocytes (16-61%) with a predominance of T4lymphocytes (65.5-84.5 %). We conclude that respiratory complaints and T4-lymphocytic alveolitis can be associated with giant cell arteritis.
Clinical Rheumatology, 2006
Anamnese en lichamelijk onderzoek, 2016
Nederlands tijdschrift voor geneeskunde, Jan 29, 2003
Two patients, a woman aged 66 and a man aged 56 years, with an inflammatory syndrome, weight loss... more Two patients, a woman aged 66 and a man aged 56 years, with an inflammatory syndrome, weight loss, joint pain and abdominal lymphadenopathy received long-term treatment with corticosteroids for alleged sarcoidosis. No long-term remission was induced and the patients were referred for a second opinion. Eventually the diagnosis of Whipple's disease was established 5 years after the appearance of the first symptoms in the case of the female patient and 4 years after in the case of the male patient. Both patients showed a marked clinical improvement after treatment with trimethoprim-sulfamethoxazole. An atypical presentation of alleged sarcoidosis should suggest the possibility of Whipple's disease, especially in the case of gastrointestinal symptoms and the failure to respond to corticosteroids, and warrants duodenal biopsy. The presence of granulomas with an elevated angiotensin-converting enzyme level is not pathognomonic for sarcoidosis. It is vitally important to distinguis...
Acta clinica Belgica, Jan 6, 2015
Background: Polyarteritis nodosa (PAN) is a rare form of systemic vasculitis, characterized by ne... more Background: Polyarteritis nodosa (PAN) is a rare form of systemic vasculitis, characterized by necrotizing inflammation of medium-sized vessels. In clinical practice, the distinction is made between a limited, mostly cutaneous, form and a generalized form. The Chapel Hill Consensus Conference of 2012 on the classification of the vasculitides classifies PAN as a medium vessel vasculitis, whereas the limited forms fall under the heading 'single-organ vasculitis' (SOV), with subdivions such as 'cutaneous arteritis' (formerly called cutaneous PAN) and 'others'. In this last category, forms of PAN limited to a single organ (e.g. testicle, gall bladder or appendix) should be categorized. The relation between classical and limited forms of PAN remains enigmatic. Objective: To compare demographics, clinical characteristics and prognosis between SOV and generalized PAN. Methods: Clinical files of all patients with a diagnosis of classical or limited PAN made in the de...
Platelets, 1996
There is controversy in the literature regarding the effects of plasmin on human platelets. We ha... more There is controversy in the literature regarding the effects of plasmin on human platelets. We have studied the effects of plasmin on platelet glycoproteins, aggregation, shape change and secretion and found them to be dependent on experimental conditions: (a) Plasmin's effects on human platelets are only seen in gel-filtered platelets (GFP), presumably because in platelet rich plasma plasmin is bound to a2-antiplasmin; (b) in GFP to which fibrinogen has been added, platelet function remains intact; and (c) in the absence of fibrinogen, the effect of plasmin on GFP depends on whether stirring is performed or not. With stirring, platelets undergo shape change, secretion and aggregation in response to added plasmin. Aggregation is much stronger when CaCl(z) 1 mM is added. Without stirring, preincubation of GFP with plasmin leads to inhibition of platelet aggregation induced by subsequent platelet stimuli (thrombin, collagen, ristocetin or U46619). We have demonstrated that plasmin is a true platelet activating agent, in the sense that it induces platelet shape change and secretion. Plasmin will induce aggregation when added to stirred GFP. This may be because stirring protects glycoprotein (GP) IIbIIIa bound fibrinogen from being degradated by plasmin. When added to unstirred GFP, GP IIbIIIa bound fibrinogen may be readily accessible to degradation by plasmin, which may then behave like a platelet inhibitor.
Pediatric Transplantation, 2006
Journal of Clinical Immunology, 1984
European Radiology, 2004
Accepted: 7 July 2003 Published online: 21 October 2003 © Springer-Verlag 2003 Sir, Increased upt... more Accepted: 7 July 2003 Published online: 21 October 2003 © Springer-Verlag 2003 Sir, Increased uptake of F-18 fluorodeoxyglucose (FDG) in the aortic arch and its proximal branches suggests large vessel vasculitis [1, 2]. The differential diagnosis of Takayasu arteritis and temporal arteritis may be difficult. The 5 patients described by Meller et al. (3 women and 2 men; median age 60 years, age range 56–72 years) [3] have the typical characteristics of temporal arteritis and not those of Takayasu arteritis. These two large-vessel vasculitides are most clearly distinguished by the criterion of age and other epidemiological and clinical features [4, 5]. Approximately 90% of patients with Takayasu arteritis are less than 40 years of age, in contrast to those with temporal arteritis who tend to be older than 50 years. Takayasu arteritis is more common in Asians than in other racial groups. In contrast, temporal arteritis is most common in northern Europeans. The patients presented by Meller et al. presented with fever and other non-specific symptoms. Systemic symptoms occur in less than 30% of cases of Takayasu arteritis but are prevalent in patients with temporal arteritis [5]. Case series of patients with fever of unknown origin from western countries only occasionally include Takayasu arteritis, whereas temporal arteritis is the most frequent diagnosis in elderly patients (65 years of age or older) with fever of unknown origin [6]. Meller et al. performed Doppler ultrasonography of the temporal arteries. The contribution of this technique to the diagnosis of temporal arteritis is controversial. A recent study reported a sensitivity of only 40% [7]. Moreover, temporal artery involvement is not obligatory in temporal arteritis. In fact, one study reported negative temporal artery biopsy findings in 42% of patients with temporal arteritis presenting with large-vessel disease [8]. Our group and others have shown that FDG PET can be used to visualize inflammation of the aorta and its major branches in temporal arteritis [1, 2], yielding images very similar to the ones obtained in the patients described by Meller et al. [3]. Clinicians who are aware of the value of FDG PET in temporal arteritis will favor a diagnosis of temporal arteritis, not of Takayasu arteritis, in the patients presented by Meller et al. [3]. This distinction is important from the standpoint of potential complications and treatment options.
Clinical Rheumatology, 2001
Patients with systemic vasculitis represent an enormous diagnostic and therapeutic challenge for ... more Patients with systemic vasculitis represent an enormous diagnostic and therapeutic challenge for the medical profession. Diagnosis can be extremely difficult if presentation is atypical, without skin lesions or frank glomerulonephritis. Treatment consists mainly of steroids, either alone or in combination with cyclophosphamide, azathioprine, methotrexate or cyclosporine, depending on the exact type of vasculitis and the organs involved. For Kawasaki disease, intravenous immunoglobulins are the first choice. For hepatitis B-associated polyarteritis nodosa, Guillevin et al. [1] have demonstrated the effectiveness of a combination of an antiviral drug (interferon or vidarabine), plasma exchange and steroids. The rarity of these disorders does not allow every internist to gain enough experience in diagnosing and treating these patients properly. The patient described by Deléaval et al. in this issue (p. 291) did not get the stateof-the-art treatment initially. The exact diagnosis was made but the initial treatment with interferon alone was inadequate to treat this form of polyarteritis with neural involvement. Steroids (and plasma exchanges or lamivudine?) were indispensible here [2]. Fortunately, after starting the proper treatment the patient made a nearly full recovery. These are mistakes we all make from time to time. It is to the authors’ credit that they share this experience with us: we learn more from our mistakes than from the things we do right. Moreover, the field of vasculitis is evolving rapidly: great efforts are currently being made to optimise the treatment of the vasculitides. The current available therapy for severe systemic vasculitis indeed is not ideal. Immunosuppression has its price, especially in terms of infectious or neoplastic complications. The exact duration or mode of therapy is often not known. All these aspects are looked for in international multicentre studies. Because of the rarity of the vasculitides (with the exception of giant cell arteritis, which is rather common in an elderly population), no single investigator can gather enough patients to start a one-centre study. Under the auspices of the European Commission (BIOMED 1 and BIOMED 2 programs), the European Union Systemic Vasculitis Study Group (EUVAS) has started several studies comparing different types, modes and durations of treatment [3]. Researchers from the United Kingdom, Denmark, the Netherlands, Germany, France, Spain, Italy, Sweden, Greece and Belgium are involved. Project leader is Dr Niels Rasmussen from Copenhagen, trials administration is in the hands of Dr David Jayne, co-project leader, from London. They have ended the enrolment of patients into the CYCAZAREM-study (azathioprine is as good as cyclophosphamide during remission in ANCA-positive systemic vasculitis) and the NORAM-study (methotrexate versus cyclophosphamide in the treatment of non-renal Wegener’s granulomatosis). The following studies are currently under way:
Clinical Rheumatology, 2000
We describe here a patient with abdominal periaortitis and intramural dissection as early manifes... more We describe here a patient with abdominal periaortitis and intramural dissection as early manifestations of Wegener's granulomatosis (WG). Surgical biopsies taken from the retroperitoneal inflammatory tissue surrounding the aorta showed granulomatous vasculitis. The patient had antiproteinase-3 antibodies and suffered from nasal, pulmonary, nervous and renal WG involvement. Although being a vasculitis of medium size and small vessels, WG should be included in the systemic vasculitides which can give rise to (peri)aortic inflammation.
Clinical Rheumatology, 2004
Clinical Rheumatology, 1999
We describe three patients with histologically proven giant cell arteritis who presented with res... more We describe three patients with histologically proven giant cell arteritis who presented with respiratory complaints. In one patient, dry cough and dyspnoea dominated the clinical picture. In the other two patients, a diagnosis of giant cell arteritis was readily suspected by the presence of typical complaints, although both patients spontaneously mentioned a persistent cough and dyspnoea, respectively. Radiographs of the chest were normal. Lung function tests, including a carbon monoxide (CO)-diffusion capacity measurement, were always normal. Broncho-alveolar lavage fluid examination showed a normal cell count but an increased number of lymphocytes (16-61%) with a predominance of T4lymphocytes (65.5-84.5 %). We conclude that respiratory complaints and T4-lymphocytic alveolitis can be associated with giant cell arteritis.
Clinical Rheumatology, 2006