D-dimer: Preanalytical, analytical, postanalytical variables, and clinical applications

Post-expiry stability of freeze-dried plasma under field conditions - Can shelf life be extended?

BACKGROUND

This prospective study evaluated the effect of routine, uncontrolled, Israeli field storage conditions on the safety and efficacy of Lyo-Plas N Freeze-Dried Plasma (FDP) at the end of the manufacturer's shelf life, and up to 24 months post expiry. Clotting factors V, VIII and XI, proteins S, C, fibrinogen, PTT, ATIII, VWF, and INR as well as TEG, DDM, residual moisture, pH, and sterility of FDP returned from field units after uncontrolled storage were evaluated.

STUDY DESIGN AND METHODS

Parameters measured at the end of manufacturer shelf life, as well as 6, 12, 18, and 24 months after expiry, were compared to those of freshly supplied FDP doses.

RESULTS

Changes were found when comparing freshly supplied FDP to all field-stored groups in INR, PT, PTT, pH, fibrinogen, and factor VIII. A significant change was also seen in Factor XI in the 12, 18, and 24 months post-expiry samples, Factor V and R in the 24 months post-expiry samples, MA in the 12, 24 months post-expiry group, and Protein C in the 18 months post-expiry group. An increase in the residual moisture from 0.90% in freshly supplied FDP to 1.35% in 24 months post-expiry FDP.; all p < .05. No growth was found in sterility analysis.

CONCLUSION

Despite uncontrolled field storage conditions, the findings demonstrate that the safety and efficacy of FDP units, stored in uncontrolled conditions are only slightly affected, even beyond their expiration date. This information allows consideration of possibly extending the shelf life.

Thromboembolism, Hypercoagulopathy, and Antiphospholipid Antibodies in Critically Ill Coronavirus Disease 2019 Patients: A Before and After Study of Enhanced Anticoagulation

Supplemental Digital Content is available in the text.

To determine the prevalence of thrombotic events, functional coagulation tests, inflammatory biomarkers, and antiphospholipid antibodies before and after enhanced anticoagulation in critically ill coronavirus disease 2019 patients.

D-dimer levels over time after anticoagulation and the association with recurrent venous thromboembolism

INTRODUCTION

D-dimer measured shortly after discontinuation of anticoagulation by an immunoturbidimetric assay predicts the risk of recurrent venous thromboembolism (VTE). We assessed the performance of this assay over time and its association with recurrent VTE.

MATERIALS AND METHODS

We followed 556 patients with a first VTE for a median of 9.6 years. The study end point was recurrent VTE. D-dimer was measured 3 weeks, and 3, 9, and 15 months after discontinuation of anticoagulation in plasma using an immunoturbidimetric assay (INNOVANCE D-Dimer). To estimate the effect of longitudinal D-dimer on the recurrence risk, we used a dynamic prediction Cox model with landmark times (3 weeks, and 3, 9, 15 months) as a stratification factor.

RESULTS

135 patients had recurrent VTE. D-dimer levels varied between patients but without a consistent pattern. Levels increased slightly over time [0.7% increase (95% CI: 0.5-0.9; p < 0.001)/month]. D-dimer levels were positively correlated with body mass index (BMI) [2% (95% CI: 1.1-2.9; p < 0.001) increase/1 unit BMI increase], and were 14.8% (95% CI: 5.1-25.3; p = 0.002) higher in women than in men. The recurrence risk with doubling D-dimer levels was higher after 3 weeks, 3, 9 and 15 months [hazard ratios 1.4 (1.06-1.84), 1.37 (1.06-1.77), 1.31 (1.04-1.65) and 1.26 (1.01-1.57), respectively].

CONCLUSIONS

In patients with a first VTE, immunoturbidimetric D-dimer levels are associated with the risk of recurrence at multiple times points from 3 weeks up to 15 months after discontinuation of oral anticoagulation.

Bone Microthrombus Promotes Bone Loss in Iron Accumulation Rats

In the present study, we investigated the changes of the coagulation state, bone microthrombus, microvascular bed and bone density levels in iron accumulation rats. Meanwhile,the effect of anticoagulation therapy on bone mineral density was further investigated. We established two groups: a control (Ctrl) group and an iron intervention (FAC) group. Changes in coagulation function, peripheral blood cell counts, bone microthrombus, bone vessels and bone mineral density were compared between the two groups. We designed the non-treatment group and treatment group to study the changes of bone mineral density by preventing microthrombus formation with the anticoagulant fondaparinux. We found that the fibrinogen and D-dimer contents were significantly higher, whereas the thrombin time (TT) and prothrombin time (PT) were significantly shorter in the FAC group. After ink staining, the microvascular bed in the FAC group was significantly reduced compared with that in the Ctrl group. HE and Martius Scarlet Blue (MSB) staining showed microthrombus in the bone marrow of the iron accumulation rats. Following anticoagulation therapy, the bone microcirculation vascular bed areas in the treatment group rats were significantly increased. Furthermore, the bone mineral density was increased in the treatment group compared with that in the non-treatment group. Through experiments, we found that the blood in iron accumulation rat was relatively hypercoagulable; moreover, there was microthrombus in the bone marrow, and the bone vascular bed was reduced. Additionally, anticoagulation was helpful for improving bone microcirculation, reducing microthrombus and decreasing bone loss.

Verification of automated latex-enhanced particle immunoturbidimetric D-Dimer assays on different analytical platforms and comparability of test results

INTRODUCTION

The aim of the study was the analytical verification of automated latex-enhanced particle immunoturbidimetric (LPIA) D-Dimer assay INNOVANCE D-dimer on Sysmex CS-5100 and Atellica COAG 360 analysers, and HemosIL D-dimer HS500 on ACL TOP 550, as well as the comparison with the enzyme-linked immunofluorescent assay (ELFA) on the miniVidas analyser.

MATERIALS AND METHODS

Verification included assessment of within-run and between-run precision, bias, measurement uncertainty (MU), verification of the cut-off, method comparison between all assessed assays, and the reference commercial ELFA VIDAS D-Dimer Exclusion II.

RESULTS

Within-run coefficients of variations (CVs) ranged from 1.6% (Atellica COAG 360) to 7.9% (ACL TOP 550), while between-run CVs ranged from 1.7% (Sysmex CS-5100) to 6.9% (Atellica COAG 360). Spearman's rank correlation coefficients were > 0.99 between LPIAs and ≥ 0.93 when comparing ELFA with LPIA. Passing-Bablok regression analysis yielded constant and proportional difference for comparison of ACL TOP 550 with both Sysmex CS-5100 and Atellica COAG360, and for miniVidas with Atellica COAG360. Small proportional difference was found between miniVidas and both Sysmex CS-5100 and ACL TOP 550. Calculated MUs using D-dimer HS 500 calibrator were 12.6% (Sysmex CS-5100) and 15.6% (Atellica COAG 360), while with INNOVANCE D-dimer calibrator 12.0% (Sysmex CS-5100), 10.0% (Atellica COAG 360) and 28.1% (ACL TOP 550). Excellent agreement of results was obtained, with occasional discrepancies near the cut-off. The cut-off (0.5 mg/L FEU) was confirmed.

CONCLUSIONS

The obtained results prove satisfactory analytical performance of LPIAs, their high comparability and almost equal discriminatory characteristics, suggesting them as a valid alternative to ELFA.

Insufficient hyperfibrinolysis in COVID-19: a systematic review of thrombolysis based on meta-analysis and meta-regression

Background How aberrant fibrinolysis influences the clinical progression of COVID-19 presents a clinicopathological dilemma challenging intensivists. To investigate whether abnormal fibrinolysis is a culprit or protector or both, we associated elevated plasma D-dimer with clinical variables to identify a panoramic view of the derangements of fibrinolysis that contribute to the pathogenesis of COVID-19 based on studies available in the literature. Methods We performed this systematic review based on both meta-analysis and meta-regression to compute the correlation of D-dimer at admission with clinical features of COVID-19 patients in retrospective studies or case series. We searched the databases until Aug 18, 2020, with no limitations by language. The first hits were screened, data extracted, and analyzed in duplicate. We did the random-effects meta-analyses and meta-regressions (both univariate and multivariate). D-dimer associated clinical variables and potential mechanisms were schematically reasoned and graphed. Findings Our search identified 42 observational, or retrospective, or case series from six countries (n=14,862 patients) with all races and ages from 1 to 98-year-old. The weighted mean difference of D-dimer was 0.97 μg/mL (95% CI 0.65, 1.29) between relatively mild (or healthy control) and severely affected groups with significant publication bias. Univariate meta-regression identified 58 of 106 clinical variables were associated with plasma D-dimer levels, including 3 demographics, 5 comorbidies, 22 laboratory tests, 18 organ injury biomarkers, 8 severe complications, and 2 outcomes (discharge and death). Of these, 11 readouts were negatively associated with the level of plasma D-dimer. Further, age and gender were confounding factors for the identified D-dimer associated variables. There were 22 variables independently correlated with the D-dimer level, including respiratory rate, dyspnea plasma K+, glucose, SpO2, BUN, bilirubin, ALT, AST, systolic blood pressure, and CK. We thus propose that "insufficient hyperfibrinolysis (fibrinolysis is accelerated but unable to prevent adverse clinical impact for clinical deterioration COVID-19)" as a peculiar mechanism. Interpretation The findings of this meta-analysis- and meta-regression-based systematic review supports elevated D-dimer as an independent predictor for mortality and severe complications. D-dimer-associated clinical variables draw a landscape integrating the aggregate effects of systemically suppressive and locally (i.e., in the lung) hyperactive derangements of fibrinolysis. D-dimer and associated clinical biomarkers and conceptually parameters could be combined for risk stratification, potentially for tracking thrombolytic therapy or alternative interventions.

Reliability of d-Dimer Determination in Diagnosis of Peri-Prosthetic Joint Infection: A Systematic Review and Meta-Analysis

Background: Surgeons continue to seek indicators for the diagnosis of peri-prosthetic joint infection (PJI), which is a serious complication after total joint arthroplasty (TJA). Many recent studies have assessed the value of d-dimer in diagnosing PJI because of the close relation between the d-dimer value and inflammation. However, the conclusions from different studies are still disputed. Methods: We searched for studies published from 2011 to March 2020 using online databases and screened studies based on the inclusion criteria. Diagnostic parameters of d-dimer, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were calculated, including the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and the area under the curve (AUC). In addition, univariate meta-regression and subgroup analyses were performed to identify sources of heterogeneity. Results: A total of nine studies with 431 Patients with PJI were included. The pooled sensitivity, specificity, DOR, and AUC of d-dimer were 0.82 (95% confidence interval [CI], 0.73-0.89), 0.73 (95% CI, 0.58-0.83), 12 (95% CI, 5-30), and 0.85 (95% CI, 0.82-0.88), respectively. In addition, the sensitivity, specificity, and AUC of CRP were 0.78 (95% CI, 0.73-0.83), 0.80 (95% CI, 0.73-0.86) and 0.85 (95% CI, 0.81-0.87), respectively, whereas those of ESR were 0.68 (95% CI, 0.60-0.74), 0.83 (95% CI, 0.75-0.88), and 0.80 (95% CI, 0.76-0.83), respectively. Conclusions: d-dimer determination had similar performance to CRP and ESR in the diagnosis of PJI and may be a good addition to the current diagnostic criteria.

Management of the thrombotic risk associated with COVID-19: guidance for the hemostasis laboratory

Coronavirus disease 2019 (COVID-19) is associated with extreme inflammatory response, disordered hemostasis and high thrombotic risk. A high incidence of thromboembolic events has been reported despite thromboprophylaxis, raising the question of a more effective anticoagulation. First-line hemostasis tests such as activated partial thromboplastin time, prothrombin time, fibrinogen and D-dimers are proposed for assessing thrombotic risk and monitoring hemostasis, but are vulnerable to many drawbacks affecting their reliability and clinical relevance. Specialized hemostasis-related tests (soluble fibrin complexes, tests assessing fibrinolytic capacity, viscoelastic tests, thrombin generation) may have an interest to assess the thrombotic risk associated with COVID-19. Another challenge for the hemostasis laboratory is the monitoring of heparin treatment, especially unfractionated heparin in the setting of an extreme inflammatory response. This review aimed at evaluating the role of hemostasis tests in the management of COVID-19 and discussing their main limitations.

Analysis of risk factors for high postoperative D-dimer levels: A single-center nurse-observational study

BACKGROUND

As an elevated D-dimer level is directly proportional to the degrees of trauma and coagulation, it is often used to assess the severity of the trauma as well as the risk of thrombosis. This study aimed to investigate the risk factors for a high postoperative D-dimer level.

METHODS

A total of 623 patients undergoing radical mastectomy were included. The association between various clinicopathological factors and D-dimer variation was examined.

RESULTS

Age, neoadjuvant chemotherapy, diabetes, and elevated neutrophil count were significant risk factors for D-dimer variation, after adjusting for other factors.

CONCLUSIONS

This study has identified the characteristics of patients who are likely to experience considerable postoperative increases in the D-dimer level. The development of effective nursing interventions for these patients is the focus of future studies.

Understanding the Pathophysiology of COVID-19: Could the Contact System Be the Key?

To date the pathophysiology of COVID-19 remains unclear: this represents a factor determining the current lack of effective treatments. In this paper, we hypothesized a complex host response to SARS-CoV-2, with the Contact System (CS) playing a pivotal role in innate immune response. CS is linked with different proteolytic defense systems operating in human vasculature: the Kallikrein–Kinin (KKS), the Coagulation/Fibrinolysis and the Renin–Angiotensin (RAS) Systems. We investigated the role of the mediators involved. CS consists of Factor XII (FXII) and plasma prekallikrein (complexed to high-molecular-weight kininogen-HK). Autoactivation of FXII by contact with SARS-CoV-2 could lead to activation of intrinsic coagulation, with fibrin formation (microthrombosis), and fibrinolysis, resulting in increased D-dimer levels. Activation of kallikrein by activated FXII leads to production of bradykinin (BK) from HK. BK binds to B2-receptors, mediating vascular permeability, vasodilation and edema. B1-receptors, binding the metabolite [des-Arg⁹]-BK (DABK), are up-regulated during infections and mediate lung inflammatory responses. BK could play a relevant role in COVID-19 as already described for other viral models. Angiotensin-Converting-Enzyme (ACE) 2 displays lung protective effects: it inactivates DABK and converts Angiotensin II (Ang II) into Angiotensin-(1-7) and Angiotensin I into Angiotensin-(1-9). SARS-CoV-2 binds to ACE2 for cell entry, downregulating it: an impaired DABK inactivation could lead to an enhanced activity of B1-receptors, and the accumulation of Ang II, through a negative feedback loop, may result in decreased ACE activity, with consequent increase of BK. Therapies targeting the CS, the KKS and action of BK could be effective for the treatment of COVID-19.

Covid-19: The Rollercoaster of Fibrin(Ogen), D-Dimer, Von Willebrand Factor, P-Selectin and Their Interactions with Endothelial Cells, Platelets and Erythrocytes

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), also known as coronavirus disease 2019 (COVID-19)-induced infection, is strongly associated with various coagulopathies that may result in either bleeding and thrombocytopenia or hypercoagulation and thrombosis. Thrombotic and bleeding or thrombotic pathologies are significant accompaniments to acute respiratory syndrome and lung complications in COVID-19. Thrombotic events and bleeding often occur in subjects with weak constitutions, multiple risk factors and comorbidities. Of particular interest are the various circulating inflammatory coagulation biomarkers involved directly in clotting, with specific focus on fibrin(ogen), D-dimer, P-selectin and von Willebrand Factor (VWF). Central to the activity of these biomarkers are their receptors and signalling pathways on endothelial cells, platelets and erythrocytes. In this review, we discuss vascular implications of COVID-19 and relate this to circulating biomarker, endothelial, erythrocyte and platelet dysfunction. During the progression of the disease, these markers may either be within healthy levels, upregulated or eventually depleted. Most significant is that patients need to be treated early in the disease progression, when high levels of VWF, P-selectin and fibrinogen are present, with normal or slightly increased levels of D-dimer (however, D-dimer levels will rapidly increase as the disease progresses). Progression to VWF and fibrinogen depletion with high D-dimer levels and even higher P-selectin levels, followed by the cytokine storm, will be indicative of a poor prognosis. We conclude by looking at point-of-care devices and methodologies in COVID-19 management and suggest that a personalized medicine approach should be considered in the treatment of patients.

Laboratory abnormalities and risk factors associated with in-hospital death in patients with severe COVID-19

Background

In the context of the COVID‐19 outbreak of worldwide, we aim to analyze the laboratory risk factors of in‐hospital death in patients with severe COVID‐19.

Methods

All ≥18‐year‐old patients with confirmed severe COVID‐19 admitted to Tongji Hospital (Wuhan, China) from February 3 to February 20, 2020, were retrospectively enrolled and followed up until March 20, 2020. Epidemiological, clinical, laboratory, and treatment data were collected and explored the risk factors associated with in‐hospital death.

Results

A total of 73 severe patients were enrolled in the study, of whom 20 (27%) patients died in hospital during the average 28 days of follow‐up period. The median age of non‐survivors was significantly older than survivors (69 [64‐76.5] years vs 64 [56‐71.3] years, P = .033) and 15 (75%) patients were males. The laboratory abnormalities of non‐survivors mainly presented in serious inflammation response and multiple organ failure, with high levels of cytokines and deranged coagulation parameters. Multivariable regression showed that neutrophil count greater than 4.47 × 10⁹/L (OR, 58.35; 95%CI: 2.16‐1571.69; P = .016), hypersensitivity C‐reactive protein greater than 86.7 mg/L (OR, 14.90; 95%CI: 1.29‐171.10; P = .030), creatine kinase greater than 101 U/L (OR, 161.62; 95%CI: 6.45‐4045.20; P = .002), and blood urea nitrogen greater than 6.7 mmol/L (OR, 11.18; 95%CI: 1.36‐91.62; P = .024) were risk factors for in‐hospital death.

Conclusion

The risk factors of neutrophil count, hypersensitivity C‐reactive protein, creatine kinase, and blood urea nitrogen could help clinicians to early identify COVID‐19 severe patients with poor outcomes on admission. Virus direct attack and cytokine storm play a major role in the death of COVID‐19.

Elevated levels of D-dimer tested by immunoturbidimetry are associated with the extent of severity of pre-eclampsia

OBJECTIVE

To establish the association between increased levels of D-dimer and severity of pre-eclampsia.

METHODS

A nested, prospective cohort, analytical case-control study was conducted among women with pre-eclampsia between March 2017 and March 2018. Inclusion criteria were age over 18 years, gestational age of more than 20 weeks, a single pregnancy with a living fetus, and a diagnosis of pre-eclampsia. D-dimer was measured by immunoturbidimetry at the time of diagnosis of pre-eclampsia, applying cut-off points adjusted for gestational age. Statistical analysis involved unconditional logistic regression for the association of elevated D-dimer with severe pre-eclampsia adjusted by confounding variables.

RESULTS

There were 132 patients with pre-eclampsia, of which 44 were classed as controls and 88 were classed as having severe pre-eclampsia (case group). Cohort characteristics included: age between 18 and 45 years (mean 28.0 ± 6.3 years); presence of gestational hypertension (10.6%), chronic arterial hypertension (9.0%); and gestational diabetes (5.3%). In the case group, levels of D-dimer were significantly higher than in controls (19.3% vs 2.3%, odds ratio [OR] 10.30, 95% confidence interval [CI] 1.32-80.14, P=0.004) as well as significant in the unconditional logistic regression model adjusted for maternal age, parity, gestational age, and comorbidities (OR 10.02, 95% CI 1.28-78.68, P=0.028).

CONCLUSION

Elevated levels of D-dimer and severe pre-eclampsia are strongly associated, reinforcing evidence that one of the physiopathologic bases of the condition is the activation of fibrinolysis and the coagulation system.

Coronavirus Disease 2019 (COVID-19): A Short Review on Hematological Manifestations

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a rapidly spreading and devastating global pandemic. Many researchers are attempting to clarify the mechanisms of infection and to develop a drug or vaccine against the virus, but there are still no proven effective treatments. The present article reviews the common presenting hematological manifestations of coronavirus disease 2019 (COVID-19). Elucidating the changes in hematological parameters in SARS-CoV-2 infected patients could help to understand the pathophysiology of the disease and may provide early clues to diagnosis. Several studies have shown that hematological parameters are markers of disease severity and suggest that they mediate disease progression.

Alterations of cardiac and renal biomarkers in horses naturally infected with theileria equi

Equine theileriosis due to Theileria equi is probably the most widespread and pathogenic disease of equines, which comes with major cardiac and renal complications. This study was undertaken to investigate the biomarkers of cardiac and renal functions in horses infected with T. equi and determine the association between these parameters and the level of parasitemia. Giemsa-stained blood smears from 300 horses with ages of 3-4 years old were examined for detection of T. equi on erythrocytes. Moreover, multiplex PCR was employed for confirmation of the diagnosis in the 28 positive cases. Based on the rate of red blood cell infection, the infected animals were subdivided into horses with low (n = 9), moderate (n = 13) and high (n = 6) parasitemia. The concentrations of urea, creatinine, cystatin-C, cardiac troponin I (cTn-I), homocysteine (Hcy), myocardial fractions of creatine kinase (CK-MB) and d-dimer were determined in control (healthy) horses (n = 20) and the infected animals. The results revealed that both the renal (urea, creatinine and cystatin-C) and the cardiac (cTn-I, Hcy, CK-MB and d-dimer) biomarkers increased in a parasitemia burden-dependent pattern. However, urea, creatinine, cTn-I and d-dimer levels were not significantly influenced in the horses infected with low rate (<1 %) of parasitemia (p> 0.05). Moreover, all of the biomarkers were significantly and positively associated with the parasitemia (R2> 0.5). In conclusion, T. equi infection was related to cardiac and renal complications evidenced by increase in the levels of biomarkers and evaluation of these indices may have promise for early diagnosis of the complications.

Inappropriate use of D-dimer and impact on the test characteristics for deep vein thrombosis exclusion

This study aimed to investigate the prevalence of the inappropriate use of D-dimer testing for deep vein thrombosis (DVT) exclusion, and to evaluate the diagnostic value of D-dimer testing compared between testing in appropriate and inappropriate conditions. A retrospective chart review of patients with D-dimer requests at Siriraj Hospital, Bangkok, Thailand during January-September 2017 was performed. Data relating to D-dimer requests, Wells score, imaging investigations, and coexisting conditions that cause elevated D-dimer without correlation to DVT were analyzed. From 2196 cases, there were 300 D-dimer requests for DVT diagnosis. Of those, 5 (1.7%) and 158 (53.6%) requests were considered to be absolutely inappropriate D-dimer test requests due to the absence of pre-test Wells score evaluation and testing in DVT-likely patients, respectively. One-hundred and forty-eight (49.3%) requests were considered to be the relatively inappropriate D-dimer test requests due to testing in patients with coexisting conditions that included malignancies, sepsis, surgery, trauma, arterial thrombosis, and pregnancy. Three patients had more than one of these conditions. Comparatively higher negative predictive values (NPVs) of D-dimer assay for DVT exclusion were observed when used in DVT-unlikely (100% versus 80%), and in patients without coexisting conditions (100% versus 66.7%). The present study revealed the rate of inappropriate D-dimer testing for DVT exclusion to be high and this may lead to missed DVT diagnosis, overuse of imaging study, and unnecessary cost of D-dimer testing. Appropriate patient selection before test request can improve the NPV of D-dimer for DVT exclusion.

A Nomogram to Predict the Pathologic Complete Response of Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Based on Simple Laboratory Indicators

BACKGROUND

Triple-negative breast cancer (TNBC) patients who achieve a pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) have better prognoses.

OBJECTIVE

This study aimed to develop an intuitive nomogram based on simple laboratory indexes to predict the pCR of standard NAC in TNBC patients.

METHODS

A total of 80 TNBC patients who received eight cycles of thrice-weekly standard NAC (anthracycline and cyclophosphamide followed by taxane) and subsequently underwent surgery in Zhejiang Cancer Hospital were retrospectively enrolled, and data on their pretreatment clinical features and multiple simple laboratory indexes were collected. The optimal cut-off values of the laboratory indexes were determined by the Youden index using receiver operating characteristic (ROC) curve analyses. Forward stepwise logistic regression (likelihood ratio) analysis was applied to identify predictive factors for a pCR of NAC. A nomogram was then developed according to the logistic model, and internally validated using the bootstrap resampling method.

RESULTS

pCR was achieved in 39 (48.8%) patients after NAC. Multivariate analysis identified four independent indicators: clinical tumor stage, lymphocyte to monocyte ratio, fibrinogen level, and D-dimer level. The nomogram established based on these factors showed its discriminatory ability, with an area under the curve (AUC) of 0.803 (95% confidence interval 0.706-0.899) and a bias-corrected AUC of 0.771. The calibration curve and Hosmer-Lemeshow test showed that the predictive ability of the nomogram was a good fit to actual observation.

CONCLUSIONS

The nomogram proposed in the present study exhibited a sufficient discriminatory ability for predicting pCR of NAC in TNBC patients.