Hemostatic Abnormalities in Severe Renal Failure: Do They Bark or Bite?

Abstract

Abnormal primary hemostasis is believed to be the most significant contributor to uremic bleeding. This study aimed to describe the prevalence and profile of primary and secondary hemostatic disorders in patients with chronic kidney disease (CKD) Stages 4 and 5 and to determine their association if any, with degree of uremia. Stages 4 and 5 predialysis CKD patients attending nephrology outpatient clinic were prospectively recruited and the following bleeding parameters were measured in all patients: platelet count, bleeding time (BT), Factor VIII assay, von Willebrand factor antigen (vWF:Ag), vWF:ristocetin cofactor activity (vWF:RCo), ratio of vWF:ristocetin cofactor activity to vWF antigen (vWF:RCo/vWF:Ag), prothrombin time (PT), and activated partial thromboplastin time (aPTT). Forty-five patients (80%, males) with a mean age of 39.4 years, 82% (n = 37) in Stage 5 CKD, were recruited for the study. The prevalence of thrombocytopenia was significantly higher among patients from West Bengal (15/26, 57.7%) compared to other study patients (2/19, 10.5%; P = 0.001); however, all had macrothrombocytes with normal BT, suggestive of the Harris syndrome. Factor VIII, vWF:Ag, vWF:RCo, vWF:RCo/vWF:Ag ratio, BT, PT, and aPTT were abnormal in 0 (0%), 0 (0%), 0 (0%), 4 (8.8%), 1 (2.2%), 7 (15.6%), and 5 (11.1%) patients, respectively. Except for thrombocytopenia, the prevalence of hemostatic abnormalities did not differ between CKD Stages 4 and 5. Hemostatic abnormalities are uncommon in Stages 4-5 CKD and except for thrombocytopenia, are not associated with degree of uremia. Constitutional macrothrombocytopenia is associated with normal BT even in CKD.

Keywords: Bleeding time; Harris syndrome; chronic kidney disease; hemostasis; macrothrombocytopenia.

Figure 1

Distribution of platelet count in West Bengal and non-West Bengal study participants (expressed per mm³)

Figure 2

Distribution of hemostatic test abnormalities in the study population. (a) Platelet count expressed per mm³ (horizontal bars represent normal range of values). (b) Bleeding time in minutes (horizontal bars represent normal range of values). (c) Factor VIII concentration in IU (horizontal bars represent normal range of values). (d) von Willebrand Antigen concentration in U/dl (horizontal bars represent normal range of values). (e) Ristocetin cofactor activity in % (horizontal bars represent normal range of values). (f) Activated partial thromboplastin time in seconds (horizontal bars represent normal range of values). (g) Prothrombin time in seconds (horizontal bars represent normal range of values)