Factors associated with the platelet count in patients with chronic hepatitis C.
BACKGROUND
There are many potential causes of thrombocytopenia in patients with chronic hepatitis C (CHC).


OBJECTIVE
We sought to determine the association between thrombopoietin (TPO) level, immature platelet fraction (IPF), immunoglobulin G (IgG) level, spleen size, and the platelet count in CHC.


METHODS
We studied a consecutive sample of patients enrolled in an observational study at a referral-based research center, excluding subjects based on eligibility criteria. TPO, glycocalicin, and von Willebrand Factor (vWF) levels were determined using stored sera. Hepatic fibrosis was assessed via transient elastography (TE) when available, and clinical laboratory values and radiologic data were obtained from the medical record. We performed analyses of the relationships between independent variables and the platelet count.


RESULTS
On univariate analysis, the following variables were significantly associated with the platelet count: age, alanine aminotransferase (ALT), direct bilirubin, total bilirubin, IPF, international normalized ratio (INR), spleen size, vWF, glycocalicin, fibrosis stage on liver biopsy, and TE (P-values all <0.05). A multivariable model determined that imputed TE score, TPO, IPF, and spleen size were independently associated with the platelet count (P-values all<0.05).


CONCLUSIONS
The platelet count in CHC is significantly associated with fibrosis, TPO level, IPF, and spleen size. Our findings challenge the proposed mechanism of decreased TPO levels or decreased bone marrow production of platelets as a cause of thrombocytopenia in CHC. Future studies focusing on the effects of fibrosis and splenomegaly on platelets may shed more light on the pathophysiology of thrombocytopenia in patients with CHC.
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA; Division of Gastroenterology, UCSF Liver Center, University of California, San Francisco, USA. Electronic address: tanam@medsfgh.ucsf.edu.
Michele M
MM
Tana
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Xiongce
X
Zhao
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Alyson
A
Bradshaw
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Mi Sun
MS
Moon
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Sandy
S
Page
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Tiffany
T
Turner
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Elenita
E
Rivera
National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
David E
DE
Kleiner
Liver Diseases Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bldg. 10 Rm. 9B16, Bethesda, MD 20892, USA.
Theo
T
Heller
D000328:Adult; D001706:Biopsy; D001792:Blood Platelets / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005355:Fibrosis / Q000097:blood; D019698:Hepatitis C, Chronic / Q000097:blood*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008099:Liver / Q000473:pathology; D008103:Liver Cirrhosis / Q000097:blood; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D019007:P-Selectin / Q000378:metabolism; D010976:Platelet Count; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*; D012189:Retrospective Studies; D013154:Spleen / Q000473:pathology; D013926:Thrombopoietin / Q000097:blood*; D014841:von Willebrand Factor / Q000378:metabolism*
D007074:Immunoglobulin G; D019007:P-Selectin; D019038:Platelet Glycoprotein GPIb-IX Complex; C023592:glycocalicin; D014841:von Willebrand Factor; D013926:Thrombopoietin
Conceptual model; Non-invasive markers; Platelet biology