Jacek Borawski

Unfractionated heparin and low-molecular-weight heparins are traditionally used in the treatment of hypercoagulable states and thrombotic complications as well as for blood anticoagulation during hemodialysis procedures in end-stage chronic kidney disease patients. This article highlights the principal anticoagulant mechanisms of the agents, their anti-inflammatory properties and the effects of heparin on other biological and human body systems. Based on our quarter-of-century research, we present the originally discovered hemostatic effects and activation of multipotential growth factors by different heparins administered for hemodialysis. The new effects of the heparinoid drug, sulodexide in healthy humans are also presented.

INTRODUCTION AND AIMS: Sclerostin (Scl) is strongly implicated in vascular calcification (VC, particularly severe in CKD pts) and angiogenesis, and localizes within endothelial glycocalyx and arterial wall. Circulating levels of this calcification inhibitor in maintenance HD pts are high, but its meaning and predictive values for VC extent, cardiovascular morbidity and survival are equivocal and even contradictory, despite of extensive studies. It has been, however, disregarded so far that Scl molecule incorporates a heparin-binding site and its in vivo metabolism may be affected by exogenous heparin, i.e. that universally used for HD procedure anticoagulation.We studied if low-molecular-weight heparin enoxaparin (ENX) stimulates intravascular Scl release during HD.

Sclerostin (Scl) is implicated in vascular calcification and angiogenesis and localizes within vasculature. Its molecule incorporates a heparin-binding site that implies also binding to endothelial glycocalyx. We preliminary tested whether intravenous (IV) low-molecular-weight heparin enoxaparin can stimulate intravascular release of this calcification inhibitor in humans. Sixteen male volunteers were injected with a bolus of 1 mg/kg body weight of enoxaparin. After 10 minutes, plasma immunoreactive Scl levels increased uniformly by a mean of 184% versus baseline level of 0.56 ± 0.17 ng/mL ( P = .0004). Plasma Scl levels were found still elevated after 2 and 6 hours (with a median of 20.9% and 8.69%, respectively) and became normal after 24 hours. The percentage of increase (Δ) in plasma Scl after 10 minutes was directly correlated with enoxaparin dose per kg/m² of body mass index (ρ = 0.587, P = .017) and strongly inversely correlated with the preinjection Scl levels (ρ = −0.747, P = .0008). A robust negative association between the ΔScl increase after 10 minutes and the ΔScl decrease after 2 hours versus 10 minutes was observed (ρ = −0.835, P < .0001). Complementary in vitro spiking experiment showed no effects of enoxaparin addition and whole blood incubation on plasma Scl levels when measured with the immunoassay. This study shows that enoxaparin has a stimulating effect on the intravascular release of calcification inhibitor Scl in healthy men. This novel pharmacological action of the popular anticoagulant drug seems important in cardiovascular medicine.

Heparin (both unfractionated and low molecular weight) is not only a potent anticoagulant but also has many pleiotropic effects, some of which are mediated by cytokine release. We compared the effect of hemodialysis (HD) with enoxaparin as an anticoagulant and without systemic anticoagulation (heparin-grafted membrane—Evodial) on the release of monocyte chemoattractant protein 1 (MCP-1), endostatin (ES) and activin A (Act-A). Nineteen stable HD patients were dialyzed with or without heparin, and plasma levels of MCP-1, ES and Act-A were measured after such a dialysis. During HD with Evodial, the intradialytic levels of all three cytokines were 2–3 folds lower. The between-anticoagulant differences were significant over time for all three cytokines: MCP-1 (P < 0.001), ES (P < 0.001) and Act-A (P < 0.001). This striking effect of heparin-free dialysis with Evodial membrane may be beneficial not only because it reduces the possibility of bleeding complications but also because it might reduce proinflammatory cytokine concentration and therefore contribute to the improvement in endothelial function. Further studies are needed to determine whether it has a positive effect on morbidity and mortality of maintenance HD patients.

Myeloperoxidase (MPO) is a proteolytic and prooxidant enzyme largely assembled with the vascular wall, and a heparin‐binding protein. We studied if low‐molecular‐weight heparin enoxaparin administered for hemodialysis (HD) anticoagulation causes systemic MPO activation. Plasma MPO levels were measured in patients undergoing maintenance HD with an intravenous bolus of enoxaparin. Patients were retested during HD employing dialyzers with heparin‐grafted polyacrylonitrile membrane and no systemic enoxaparin administration. During enoxaparin‐anticoagulated HD plasma MPO levels strikingly increased in all patients (8.6‐fold at 10 minutes and 3.3‐fold at 120 minutes, both P < 0.0001). The increments were directly associated with the enoxaparin dosage and strongly inversely with the predialysis levels of the enzyme. The increase in plasma MPO during systemic heparin‐free HD was significantly less pronounced. Enoxaparin administered for HD anticoagulation induces a marked and dose‐dependent increase in plasma MPO as a plausibly favorable result of the liberation of the enzyme from the vascular wall.

Background: Hepatocyte growth factor (HGF), endogenous cytokine with pleiotropic repairing and regeneration properties in relation to most tissues and organs, contributes to the progression of periodontal disease (PD). Furthermore, PD is a significant health problem in patients with chronic renal failure (CRF). The role of HGF in the development of PD in this specific population was not a subject of research so far. Material and methods: The following groups were enrolled in the study: (1) 26 chronic hemodialysis (HD) subjects, (2) 26 patients treated by continuous ambulatory peritoneal dialysis (CAPD), (3) 28 predialysis CRF patients, (4) 26 subjects with advanced PD (without coexisting diseases), and (5) 20 healthy subjects without PDs. HGF level in saliva was measured using the immunoenzymatic method. Gingival index, papillary bleeding index, plaque index, and the loss of clinical attachment level were evaluated. Results: The HGF level in saliva of HD patients was twice higher than in that of subjects with healthy periodontium. Direct relationships between proper HGF level in saliva and the indices GI, PBI, and PI in CAPD-treated patients and with more severe PD were shown. It was found that PD is most advanced in HD patients, moderately in CAPD-treated patients and to the smallest extent in predialysis CRF patients. Conclusions: The HGF level in mixed saliva is the index of PD progression in subjects without renal failure and in CAPD-treated patients. PD is common in renal failure patients and is a significant problem concerning general health status.

Hepatocyte growth factor (HGF), activin A (Act A), and follistatin (FS) compose an organotrophic system; interestingly it is modified by heparin. To understand if LMWHs (considered distinct drugs) have different clinical profiles regarding the above growth factors, we studied the effects of enoxaparin, nadroparin, and dalteparin on their plasma levels. Seventeen chronic HD patients completed this prospective, crossover trial. They were randomized into six groups: each patient was administered enoxaparin (effective dose of 0.75 mg/kg), nadroparin (70.4 IU/kg) and dalteparin (78.6 IU/kg) in three time periods of two months each. At the end of this period, the cytokine's plasma levels were measured by immunoassays at the start and at 10 min and 180 min of the HD procedure. At 10 min, we observed a striking increase in plasma HGF (32-fold), Act A (4-fold), and FS (53%), all p = 0.0003. The levels of HGF and Act A remained markedly elevated after 180 min (by 295% and 87%, respectively; both p < 0.002), while those of FS returned to baseline. There were no differences in cytokine profile comparing both their peak concentrations and the areas under the curve. Enoxaparin, dalteparin, and nadroparin are seemingly not different considering the release of HGF/Act A/FS during HD procedures; this may reflect their similar profile in other aspects. Moreover, the concentrations of HGF/Act A/FS are close to therapeutic ones, which may partly explain the mechanisms underlying some of the emerging extra-anticoagulant effects of LMWHs.