Protein C and procollagen III peptide levels in patients with hepatic dysfunction after allogeneic hematopoietic stem cell transplantation

Contribution of fibrinolytic tests to the differential diagnosis of veno-occlusive disease complicating pediatric hematopoietic stem cell transplantation

BACKGROUND

Veno-occlusive disease (VOD) is a major complication following hematopoietic stem cell transplantation (HSCT). Its diagnosis is based on clinical criteria, which have a limited sensitivity. Increased plasminogen activator inhibitor-1 (PAI-1) levels have been suggested as a marker of VOD. We aimed to prospectively evaluate how the fibrinolytic parameters behaved to discriminate VOD from other liver disorders occurring after HSCT in a pediatric population.

PROCEDURES

A total of 195 HSCT were performed on 161 children and VOD complicated 11 cases (6.8%). Alanine aminotransferase, total bilirubin, PAI-1 antigen (PAI-1:Ag) and activity, t-PA antigen, D-dimer, prothrombin time, activated partial thromboplastin time, antithrombin, fibrinogen, and platelet counts were measured in 105 HSCT before and then weekly for 1 month after HSCT.

RESULTS

An early, significant increase in the fibrinolytic parameters was seen in patients who developed VOD, even before VOD was diagnosed clinically, by comparison with patients without complications or those with non-VOD liver disorders. The combined increase in bilirubin, D-dimer, and PAI-1:Ag levels beyond the normal range distinguished VOD cases from other liver complications with a high sensitivity and specificity.

CONCLUSIONS

Our study demonstrates that fibrinolytic tests can help diagnose VOD after HSCT in the pediatric population.

Alterations of hemostatic parameters in the early development of allogeneic hematopoietic stem cell transplantation-related complications

Thrombotic events are common and potentially fatal complications in patients receiving hematopoietic stem cell transplantation (HSCT). Early diagnosis is crucial but remains controversial. In this study, we investigated the early alterations of hemostatic parameters in allogeneic HSCT recipients and determined their potential diagnostic values in transplantation-related thrombotic complications and other post-HSCT events. Results from 107 patients with allogeneic HSCT showed higher levels of plasma plasminogen activator inhibitor-1 (PAI-1), fibrinogen, and tissue-plasminogen activator (t-PA) and a lower level of plasma protein C after transplantation. No change was found for prothrombin time, antithrombin III, d-dimer, and activated partial thromboplastin time following HSCT. Transplantation-related complications (TRCs) in HSCT patients were defined as thrombotic (n = 8), acute graft-versus-host disease (aGVHD, n = 45), and infectious (n = 38). All patients with TRCs, especially the patients with thrombotic complications, presented significant increases in the mean and maximum levels of PAI-1 during the observation period. Similarly, a high maximum t-PA level was found in the thrombotic group. In contrast, apparent lower levels of mean and minimum protein C were observed in the TRC patients, especially in the aGVHD group. Therefore, the hemostatic imbalance in the early phase of HSCT, reflecting prothrombotic state and endothelial injury due to the conditioning therapy or TRCs, might be useful in the differential diagnosis of the thrombotic complication from other TRCs.

Plasma protein C is a useful clinical marker for hepatic veno-occlusive disease (VOD) in stem cell transplantation

BACKGROUND

Hepatic veno-occlusive disease (VOD) is one of the most serious complications in stem cell transplantation (SCT). Although plasma protein C activity decreases in VOD after SCT, the timeframe of plasma protein C activity decreases during SCT is not known.

PROCEDURE

We examined levels of plasma protein C serially during the course of SCT to determine the critical level and risk factors for VOD.

RESULTS

Of 151 children who received SCT, 12 of them (7.9%) developed VOD. The mean minimum protein C activity in patients with VOD was significantly lower compared to that in patients without VOD (P < 0.0001). Receiver operating characteristic curve analysis revealed that the critical plasma protein C activity (cut-off point) for VOD was identified to be 34.5% with high sensitivity (100%) and specificity (83.3%), and the reduction of plasma protein C below the cut-off level (day +6.50 +/- 2.43) was observed mostly prior to the onset of VOD (day +7.33 +/- 2.64). The patients receiving melphalan in conditioning were found to be at high risk for VOD (P = 0.003). Among the melphalan containing regimens, melphalan + carboplatin + etoposide was a significant risk factor for depression of plasma protein C (P = 0.037).

CONCLUSION

Plasma protein C level was a useful parameter of VOD after SCT, and activity below 34.5% was critical for VOD. The use of melphalan in conditioning causes a high risk for VOD.

NanoLC-MS/MS analyses of urinary desmosine, hydroxylysylpyridinoline and lysylpyridinoline as biomarkers for chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) is a common and potentially lethal complication of allogeneic hematopoietic stem cell transplantation (HSCT). cGVHD as well as the transplant procedure itself (chemotherapy with or without radiotherapy) can lead to the degradation of connective tissue components such as elastin and collagen. The catabolism of these structural proteins releases desmosine (DES), lysylpyridinoline (LP), hydroxylysylpyridonoline (HP), and related pyridinium-based cross-linkers analogues that could represent potential biomarkers for cGVHD. This study reports the development of a sensitive liquid chromatography/tandem mass spectrometry method for the simultaneous analysis of N-propyl derivatives of DES, HP, and LP. The concentrations of free and total forms of urinary DES, HP, and LP were determined using synthetic deuterated internal standards. This method enabled accurate quantitation of these pyridinium-based cross-linkers from as little as 100 microL of urine with detection limits of 0.03-0.10 ng/mL. These compounds were analyzed in urine samples from three groups of patients: (1) Healthy volunteers, (2) Autologous HSCT recipients (who cannot develop cGVHD), and (3) Allogeneic HSCT recipients at onset of cGHVD. These analyses revealed that the urinary concentrations of DES, HP, and LP in the autologous recipients were greater or equal to the cGVHD group although both groups showed marked increase in the levels of these compounds compared to healthy individuals. These results suggest that the chemotherapy treatment has significant effects on the turnover of elastin and collagen, and that these biomarkers could be effective during prospective analyses to determine the onset of cGVHD.

Adapting mass spectrometry-based platforms for clinical proteomics applications: The capillary electrophoresis coupled mass spectrometry paradigm

Single biomarker detection is common in clinical laboratories due to the currently available method spectrum. For various diseases, however, no specific single biomarker could be identified. A strategy to overcome this diagnostic void is to shift from single analyte detection to multiplexed biomarker profiling. Mass spectrometric methods were employed for biomarker discovery in body fluids. The enormous complexity of biofluidic proteome compartments implies upstream fractionation. For this reason, mass spectrometry (MS) was coupled to two-dimensional gel electrophoresis, liquid chromatography, surface-enhanced laser desorption/ionization, or capillary electrophoresis (CE). Differences in performance and operating characteristics make them differentially suited for routine laboratory applications. Progress in the field of clinical proteomics relies not only on the use of an adequate technological platform, but also on a fast and efficient proteomic workflow including standardized sample preparation, proteomic data processing, statistical validation of biomarker selection, and sample classification. Based on CE-MS analysis, we describe how proteomic technology can be implemented in a clinical laboratory environment. In the last part of this review, we give an overview of CE-MS-based clinical studies and present information on identity and biological significance of the identified peptide biomarkers providing evidence of disease-induced changes in proteolytic processing and posttranslational modification.

Proteomic patterns predict acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Acute graft-versus-host disease (aGvHD) contributes significantly to morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Diagnosis of GvHD is mainly based on clinical features and tissue biopsies. A noninvasive, unbiased laboratory test for GvHD diagnosis does not exist. Here we describe the application of capillary electrophoresis coupled online with mass spectrometry (CE-MS) to 13 samples from 10 patients with aGvHD of grade II or more and 50 control samples from 23 patients without GvHD. About 170 GvHD-specific polypeptides were detected and a tentatively aGvHD-specific model consisting of 31 polypeptides was chosen, allowing correct classification of 13 of 13 (sensitivity 100.0% [95% confidence interval {CI} 75.1 to 100.0]) aGvHD samples and 49 of 50 (specificity 98.0% [95% CI 89.3 to 99.7]) control samples of the training set. The subsequent blinded evaluation of 599 samples enabled diagnosis of aGvHD greater than grade II, even prior to clinical diagnosis, with a sensitivity of 83.1% (95% CI 73.1 to 87.9) and a specificity of 75.6% (95% CI 71.6 to 79.4). Thus, high-resolution proteome analysis represents an unbiased laboratory-based screening method, enabling diagnosis, and possibly enabling preemptive therapy.

Favorable response of pediatric stem cell recipients to human protein C concentrate substitution for veno-occlusive disease

Plasminogen activator inhibitor 1 is known to be elevated in patients with hepatic VOD after intensive chemotherapy. To re-establish endogenous fibrinolysis and to inhibit thrombin formation, we used non-APC (zymogen) to normalize PAI-1 levels. As a consequence of thrombin formation inhibition and the consecutive inhibition of the coagulation cascade, this treatment is expected to reduce the elevated D-dimer level. Six pediatric stem cell recipients with moderate or severe VOD after busulfan or total body irradiation conditioning regimen are reported here who were therapy-refractory to defibrotide or rt-PA therapy. All patients had low levels of PC activity (16-39%). The administration of PC (60-240 IU/kg) led to a rapid and sustained rise in PC activity (target level >80%) with near normalization of prothrombin and partial thromboplastin time in all patients. Elevated PAI-1 levels declined. Five of the six patients showed a good clinical response with prompt resolution of clinical, sonographic, and laboratory signs of hepatic blood flow obstruction, while one patient with severe VOD, as well as concomitant liver GVHD and CMV disease, had a slow but detectable response to PC therapy. All patients survived.

Evaluation of plasma protein C activity for detection of hepatobiliary disease and portosystemic shunting in dogs

OBJECTIVE

To determine the diagnostic value of protein C (PC) for detecting hepatobiliary disease and portosystemic shunting (PSS) in dogs.

DESIGN

Prospective study.

ANIMALS

238 clinically ill dogs with (n = 207) and without (31) hepatobiliary disease, including 105 with and 102 without PSS.

PROCEDURES

Enrollment required routine hematologic, serum biochemical, and urine tests; measurement of PC activity; and a definitive diagnosis. Total serum bile acids (TSBA) concentration and coagulation status, including antithrombin activity, were determined in most dogs. Dogs were grouped into hepatobiliary and PSS categories. Specificity and sensitivity were calculated by use of a PC cutoff value of 70% activity.

RESULTS

Specificity for PC activity and TSBA concentrations was similar (76% and 78%, respectively). Best overall sensitivity was detected with TSBA, but PC activity had high sensitivity for detecting PSS and hepatic failure. Protein C activity in microvascular dysplasia (MVD; PC > or = 70% in 95% of dogs) helped differentiate MVD from portosystemic vascular anomalies (PSVA; PC < 70% in 88% of dogs). A receiver operating characteristic curve (PSVA vs MVD) validated a useful cutoff value of < 70% activity for PC.

CONCLUSIONS AND CLINICAL RELEVANCE

Combining PC with routine tests improved recognition of PSS, hepatic failure, and severe hepatobiliary disease and signified a grave prognosis when coupled with hyperbilirubinemia and low antithrombin activity in hepatic failure. Protein C activity can help prioritize tests used to distinguish PSVA from MVD and sensitively reflects improved hepatic-portal perfusion after PSVA ligation.