Procalcitonin: a marker for the diagnosis and follow-up of patients with medullary thyroid carcinoma

Serum Biochemical Markers for Medullary Thyroid Carcinoma: An Update

Introduction

Medullary thyroid carcinoma (MTC), a rare malignancy, requires early diagnosis for optimal patient outcomes. An important aspect of MTC diagnosis is the assessment of serum biomarkers. This review aimed to evaluate the use of serum biomarkers in the diagnosis, prognosis, and follow-up of MTC.

Methods

A thorough search of PubMed covering 1975 to 2022 was conducted to identify English-language articles on MTC serum biomarkers.

Results

The review revealed that calcitonin (Ctn) and carcinoembryonic antigen (CEA) remain the most important serum biomarkers for MTC diagnosis and management. Despite limited studies on procalcitonin (PCT), its stability and ability to exclude interference from inflammation make it a valuable potential marker of MTC. Although the positive rate of serum CA19-9 levels in MTC patients was not high, it can be used as an indicator of poor prognosis in advanced MTC. Other serum markers, including chromogranin A, gastrin-releasing peptide precursor, and neurospecific enolase, did not show any unique value in MTC diagnosis and management.

Conclusion

Taken together, this review emphasized the importance of serum biomarkers, particularly Ctn and CEA, in the diagnosis and management of MTC. PCT shows promise as a valuable potential marker, whereas CA19-9 can be used as a prognostic indicator of advanced MTC. Further research is needed to validate the significance of these serum biomarkers in MTC and determine the effects of confounding factors on their levels. Clinicians should consider using these markers in MTC diagnosis, prognosis, and follow-up, particularly for patients with advanced disease.

Immunohistochemistry in the pathologic diagnosis and management of thyroid neoplasms

The use of immunohistochemistry cannot be underestimated in the everyday practice of thyroid pathology. It has evolved over the years beyond the traditional confirmation of thyroid origin to molecular profiling and the prediction of clinical behavior. In addition, immunohistochemistry has served to implement changes in the current thyroid tumor classification scheme. It is prudent to perform a panel of immunostains, and the immunoprofile should be interpreted in light of the cytologic and architectural features. Immunohistochemistry can also be easily performed in the limited cellularity specimen preparation generated from thyroid fine-needle aspiration and core biopsy; however, it will require laboratory validation of immunostains specific to these preparations to avoid diagnostic pitfalls. This review discusses the application of immunohistochemistry in thyroid pathology with a focus on limited cellularity preparations.

The role of procalcitonin in the follow-up of medullary thyroid cancer

Objective

Calcitonin (Ct) represents the most important biochemical marker of medullary thyroid cancer (MTC), but has certain limits. We analyzed the performance of procalcitonin (ProCt) in follow-up MTC patients.

Methods

In this monocentric and retrospective study, we consecutively obtained ProCt and Ct values from all MTC patients that we visited during the period from April 2021 to May 2022. Patients were defined as having structural evidence of disease (29/90, 32.2%) irrespective of Ct values or, in its absence, as not evident disease (NED) if Ct was ≤10 ng/L (47/90, 52.2%), or minimal residual disease if Ct was >10 ng/L (14/90, 15.6%).

Results

Ct and ProCt values were highly correlated (r = 0.883, P < 0.01). Median ProCt values differed between NED, minimal residual disease, and structural disease, being 0.04 ng/mL, 0.26 ng/mL, and 1.98 ng/mL, respectively (P < 0.01). ProCt was undetectable (<0.04 ng/mL) in 40/47 (85.1%) of NED patients, in 3/14 (21.4%) patients with minimal residual disease and in none of the patients with a structural disease (P < 0.01). Among the 11 patients with detectable but ≤10 ng/L Ct and undetectable ProCt values, none had a structural disease. The most accurate cut-off of ProCt to distinguish between the presence or absence of a structural disease was >0.12 ng/mL (P < 0.01, area under the curve: 0.963), with the following sensitivity, specificity, positive predictive value, and negative predictive value (NPV): 100%, 83.61%, 74.4%, and 100.0%.

Conclusions

ProCt and Ct have a high correlation in MTC follow-up. ProCt may be useful as an adjunct to Ct, especially for its NPV concerning the structural disease.

Case report: Ewing sarcoma with EWSR-ERG fusion elevates procalcitonin extremely in the long term without infection

Background

Ewing sarcoma (ES) represents a rare, aggressive bone and soft-tissue cancer. Unlike breast, liver, pancreatic, and prostate cancers, Ewing sarcoma has had no representative tumor marker until now. The use of procalcitonin (PCT) as a tumor marker is also rarely reported. PCT is a clinically recognized and widely used inflammatory marker in recent years. In rare cases, PCT may also be falsely positive due to non-infectious factors. In the few previously reported papers regarding the correlation between tumors and PCT, we learned that abnormalities of PCT level can also be impacted by individual cancers.

Case presentation

Here, we first reported a case of Ewing sarcoma with markedly elevated PCT without infection and carried out some literature review. The patient was a middle-aged man with extraskeletal Ewing sarcoma whose lesion was located in the distal abdominal ileum. He had a sudden and unprovoked onset of high fever during chemotherapy before surgery. After multiple examinations, the patient's blood routine, C-reactive protein, blood culture, and CT examination showed no signs of infection, and even the culture from the end of the central venous catheter showed no pathogen growth. Only PCT increased dramatically to more than 200 ng/ml. PCT remained at this level for several months until a single abdominal lumpectomy was performed before it dropped to near-normal levels.

Conclusion

In our report, PCT is significantly elevated in Ewing sarcoma in the absence of infection. Not only that, but we particularly highlighted the precipitous drop in PCT following tumor resection.

Other markers of medullary thyroid cancer, not only calcitonin

BACKGROUND

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor originating from parafollicular C-cells. It represents 2% of all thyroid malignancies and 0.4-1.4% of all thyroid nodules. MTC has a variable clinical course, with complete remission often difficult to achieve. An early diagnosis is still crucial in MTC management, enabling a radical surgical treatment, the only chance for curing the patient. Calcitonin (Ct) is a very sensitive MTC tumor marker in patients with thyroid nodules, although Ct-negative MTCs have been described, but not all clinical guidelines recommend the Ct routine measurement in thyroid nodules because of the absolute low prevalence of MTC in the general population and the consequent scarce positive predictive value of Ct. Moreover, the specificity of moderately high Ct levels is not high. Thus, the scientific community has been investigating the possible role of other tumor markers for MTC diagnosis and prognosis.

AIM OF THE REVIEW

The present review is an attempt to summarize the knowledge available today on the role of other serum markers for MTC alternative to Ct.

CONCLUSIONS

At present, literature data does not seem solid enough yet to establish effective flowcharts in evaluating a thyroid nodule for MTC, involving alternative serum markers, particularly in cases of moderately high CT levels. MTC is a rare diagnosis in thyroid nodules, and this makes the evaluation of any tumor serum marker accuracy problematic. More extensive and prospective studies are needed to shed more light on this intriguing challenge.

High-Level Procalcitonin in Patient with Mixed Fibrolamellar Hepatocellular Carcinoma: A Case Report and Literature Review

Course of blood procalcitonin levels by days.

Determining the relationship between serum acute phase reactants and cervical premalignant lesions: a cohort study

BACKGROUND

Acute phase reactants play a role in the progression and prognosis of many malignant and premalignant tumors. This study investigated the diagnostic value of certain reactants as markers for cervical premalignant lesions.

OBJECTIVE

Despite advanced screening and vaccination programs, cervical cancer remains a serious health problem worldwide. We aimed to determine the possible relationship between premalignant cervical disease and serum acute phase reactant levels.

DESIGN AND SETTING

This study included 124 volunteers who underwent cervical cancer screening. We divided the patients into three groups according to cervical cytology and histopathological findings as follows: no cervical lesion, low-grade neoplasia, or high-grade neoplasia.

METHODS

We included women aged 25-65 years with benign smear or colposcopy results, low- and high-grade squamous intraepithelial lesions. The benign group was based only on cytology findings, whereas the other groups were based on histopathology findings. Demographic data and serum albumin, fibrinogen, ferritin, and procalcitonin levels were evaluated in the three groups.

RESULTS

We found significant differences among the three groups in terms of age, albumin level, albumin/fibrinogen ratio, and procalcitonin level. The regression analysis revealed lower serum albumin levels in the low- and high-grade squamous intraepithelial lesion groups compared with the benign group.

CONCLUSION

This is the first study to evaluate the importance of serum inflammatory markers in cervical intraepithelial lesions. Our results indicate that serum albumin level, albumin/fibrinogen ratio, procalcitonin level, and neutrophil values differ among cervical intraepithelial lesions.

Incidental diagnosis of medullary thyroid carcinoma due to persistently elevated procalcitonin in a patient with COVID-19 pneumonia: A case report

BACKGROUND

Procalcitonin (Pct) is a common biomarker in clinical practice, especially in the era of coronavirus disease 2019 (COVID-19) infection. Although it is frequently used for the diagnosis and prognostication of bacterial infections or sepsis, it is also elevated in a few other conditions, including medullary thyroid carcinoma (MTC).

CASE SUMMARY

A 43-year-old female presented with moderately severe COVID-19 pneumonia in April 2021. She gradually recovered clinically; however, despite normalization of other inflammatory markers, Pct levels remained persistently elevated. Further workup identified the cause as left lobe MTC with locoregional metastasis. Calcitonin levels were high, and carcinoembryonic antigen levels were normal. The patient underwent total thyroidectomy and neck dissection, which was followed by another radical neck dissection due to residual disease. Currently, she is doing well, nearly having completed her course of external beam radiotherapy with no recurrence. Pct is well documented as a screening tool for MTC, especially because of its stable nature compared to calcitonin in the community settings. It is important to keep in mind the differential diagnosis of MTC in patients with persistently elevated Pct levels despite normal levels of other acute phase reactants. To the best of our knowledge, this is the first report from Asia of such an incidental diagnosis of MTC due to persistently elevated Pct levels in a patient with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

CONCLUSION

Persistently elevated Pct levels can occur in any pro-inflammatory state including infections, sepsis, or acute respiratory distress syndrome. In the current setting, SARS-CoV-2 infection is one such clinical scenario, and in rare situations of persistent elevation, MTC may need to be ruled out.

The ability of inflammatory markers to recognize infection in cancer patients with fever at admission

Infection is one of the main causes of death in cancer patients. Accurate identification of fever caused by infection could avoid unnecessary antibiotic treatment and hospitalization. This study evaluated the diagnostic value of procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), and other commonly used inflammatory markers in suspected infected adult cancer patients with fever, for better use of antibiotics. This research retrospective analyzed the clinical data of 102 adult cancer patients with fever and compared the serum levels of commonly used inflammatory markers for different fever reasons. Receiver-operating characteristic (ROC) curve and logistic regression analyses were performed. In adult cancer patients with fever, the serum PCT, CRP, IL-6, and IL-10 levels of infected patients were significantly higher than uninfected patients (median 1.19 ng/ml vs 0.14 ng/ml, 93.11 mg/l vs 56.55 mg/l, 123.74 pg/ml vs 47.35 pg/ml, 8.74 pg/ml vs 3.22 pg/ml; Mann-Whitney p = 0.000, p = 0.009, p = 0.004, p = 0.000, respectively). The ROC area under the curve(AUC) was 0.769 (95% confidence interval (CI) 0.681-0.857; p = 0.000) for PCT, 0.664 (95% CI 0.554-0.775; p = 0.009) for CRP, 0.681(95% CI 0.576-0.785; p = 0.004) for IL-6, and 0.731(95% CI 0.627-0.834; p = 0.000) for IL-10. PCT had specificity of 96.67% and positive predictive value (PPV) of 97.6%, when the cut-off value is set as 0.69 ng/ml. The serum IL-6 and IL-10 levels also had significant differences between the infected and uninfected cancer patients with advanced disease (median 128.92 pg/ml vs 36.40 pg/ml, 8.05 pg/ml vs 2.92 pg/ml; Mann-Whitney p = 0.003, p = 0.001, respectively). For the patients with neutropenia, IL-6 and IL-10 had higher AUC of 0.811 and 0.928, respectively. With a cut-off of 9.10 pg/ml, IL-10 had the highest sensitivity 83.33% and specificity 100%. In adult cancer patients, PCT had the best performance compared to CRP, IL-6, and IL-10 in differentiating infected from uninfected causes of fever, with high specificity and PPV. IL-6 and IL-10 might be useful in cancer patients with severe bloodstream infections and advanced disease. However, for patients with neutropenia, IL-10 might be more valuable than PCT in diagnosing infection.

Cross-Sectional Study of Clinical Predictors of Coccidioidomycosis, Arizona, USA

Demographic and clinical indicators have been described to support identification of coccidioidomycosis; however, the interplay of these conditions has not been explored in a clinical setting. In 2019, we enrolled 392 participants in a cross-sectional study for suspected coccidioidomycosis in emergency departments and inpatient units in Coccidioides-endemic regions. We aimed to develop a predictive model among participants with suspected coccidioidomycosis. We applied a least absolute shrinkage and selection operator to specific coccidioidomycosis predictors and developed univariable and multivariable logistic regression models. Univariable models identified elevated eosinophil count as a statistically significant predictive feature of coccidioidomycosis in both inpatient and outpatient settings. Our multivariable outpatient model also identified rash (adjusted odds ratio 9.74 [95% CI 1.03–92.24]; p = 0.047) as a predictor. Our results suggest preliminary support for developing a coccidioidomycosis prediction model for use in clinical settings.

Diagnostic Utility of Procalcitonin for Sporadic Medullary Thyroid Carcinoma in Patients with Nodular Disease and Mild or Moderate Hypercalcitoninemia

Many authors recommend the measurement of serum calcitonin (Ctn) to screen for sporadic medullary thyroid carcinoma (MTC) in patients with thyroid nodules. In this situation, procalcitonin (pro-Ctn) would have greater utility in patients with hypercalcitoninemia<100 pg/ml. The aim of this study was to evaluate the utility of pro-Ctn in patients with thyroid nodules and without a suspicion of familial MTC or type 2 multiple endocrine neoplasia who had mild or moderate hypercalcitoninemia without an apparent cause. Consecutive patients with nodular thyroid disease assessed routinely by Ctn measurement were selected. Sixty patients with basal Ctn>10 pg/ml but<100 pg/ml were included. Nine patients (15%) had MTC, with cytology being diagnostic in only four. Among the 51 patients without MTC, pro-Ctn was<0.1 ng/ml in 46 (90.2%). All patients with MTC had pro-Ctn>0.1 ng/ml. Basal Ctn was>24.6 pg/ml in all patients with MTC and in 42 patients (82.3%) without MTC. It is noteworthy that among patients with basal Ctn>24.6 pg/ml (n=18) pro-Ctn>0.1 ng/ml identified all patients with MTC and 64.2% of subjects with these pro-Ctn concentrations had this tumor. In conclusion, we did not find superiority of pro-Ctn over Ctn for the diagnosis of sporadic MTC in patients with nodular disease and mild or moderate hypercalcitoninemia. However, in the case of patients with hypercalcitoninemia in the gray zone, pro-Ctn has an excellent negative predictive value while the data regarding its positive predictive value are not uniform.

Analytical Performance Evaluation of a New Calcitonin Assay

BACKGROUND

The use of efficient laboratory calcitonin (CT) testing is required for optimal management of medullary thyroid carcinoma. Several pitfalls are related to the calcitonin laboratory assays and a careful evaluation is needed. We report the analytical performances of the new Siemens ADVIA-Centaur-CALCT (CT-XPT) assay and its comparison with our standard method DiaSorin-Calcitonin-II-Gen (CT-LIA) assay.

METHODS

Analytical performance of the CT-XPT-assay, limit of blank (LOB), limit of detection (LOD), and limit of quantification (LOQ), were determined. We also evaluated the in vitro stability of the sample, together with the linearity and percentage recovery.

RESULTS

The CT-XPT-assay showed a better detection limit than the CT-LIA assay, with lower values of LOB (0.86 pg/mL vs 1.00 pg/mL) and LOQ (1.65 pg/mL vs 3.00 pg/mL). Both values were in agreement with those reported by the manufacturer. Within- and between-run precision demonstrated a good concordance of results. Regarding the in vitro stability of CT, the low CT concentration sera showed a much greater decrease in CT levels compared to the high concentration sera. Correlation studies showed a good correlation between the two methods (Kappa Cohen coefficent, KC: 0.68, agreement % for male: 89.58%; KC: 0.63; agreement % for female: 88.33%).

CONCLUSIONS

Our findings showed a good correlation between the CT-LIA and CT-XPT methods. Moreover, we demonstrated that the analytical performance of the CT-XPT assay, together with its technical specifications, could represent major features of the CT-XPT method. Collectively, the technical evaluation and the analytical results described in the presented paper highlight that the novel CT-XPT is a valid method for CT testing in a clinical diagnostic setting.

Calcitonin and complementary biomarkers in the diagnosis of hereditary medullary thyroid carcinoma in children and adolescents

OBJECTIVES

Medullary thyroid carcinoma (MTC) is a rare malignancy that is effectively curable by surgery. Unlike in adults, hereditary MTC has a predominant role in children. A fast and safe diagnosis is important to assure the good prognosis for the patients. A major cornerstone is the assessment of biomarkers, but the interpretation must respect their pre-, post- and analytical features. Especially calcitonin (Ctn) is a challenging biomarker in daily laboratory diagnostics. However, Ctn is of particular relevance for the diagnostic in MTC. The American Thyroid Association recommends thyroidectomy if the upper reference range of Ctn is exceeded. Interestingly, age-dependent reference ranges for children and adolescents have become available only recently for Ctn assays. With this review, we aim to highlight the importance of a timely diagnosis of MTC in children and adolescents.

CONTENT

Recent developments in pediatric biochemical diagnostics of MTC were summarized. This includes guidance on interpretation of RET, Ctn, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 19-9, and chromogranin A.

SUMMARY

Currently, Ctn is the most investigated biomarker in the diagnosis of MTC in children and adolescents. Other biomarkers as PCT suggest complementary evidence about pediatric MTC but their interpretation based largely on adult's data. A successful treatment of MTC requires, besides results of biomarkers, information about medical history, RET gene analysis and recent guideline knowledge.

OUTLOOK

More research is required to validate complementary biomarkers of Ctn in children. Additionally, the effect of different confounder on pediatric Ctn levels has to be further clarified.

Procalcitonin as an Alternative Tumor Marker of Medullary Thyroid Carcinoma

CONTEXT

Calcitonin (CT) measurement is pivotal in the management of medullary thyroid carcinoma (MTC), but several pitfalls can affect its reliability. Procalcitonin (ProCT) has been reported as a promising alternative MTC tumor marker.

OBJECTIVE

This study aimed to determine the ProCT diagnostic accuracy in prediction and treatment monitoring of MTC.

METHODS

Electronic databases were searched for observational studies published until May 2021 without language or time restrictions. Studies comparing ProCT and calcitonin accuracy were included. After removing duplicates and exclusion of not-eligible articles, relevant articles were screened independently by 2 reviewers. Eleven studies (4.5% of the identified studies) met the selection criteria. Two reviewers independently extracted data and assessed data quality and validity through QUADAS-2.

RESULTS

A meta-analysis was performed on 11 sufficiently clinically and statistically homogeneous studies (n = 5817 patients, 335 MTC patients). Hierarchical summary receiver operating characteristics and bivariate methods were applied. Serum ProCT was found to be a highly accurate test for MTC diagnosis and monitoring. The pooled sensitivity, specificity, positive and negative likelihood ratios, area under the curve, and positive and negative predictive values for ProCT were 0.90 (95% CI: 0.71-0.97), 1.00 (95% CI: 0.85-1.00), 288 (95% CI: 5.6-14 929.3), 0.10 (95% CI: 0.03-0.33), 0.97 (95% CI: 0.95-0.98), 99%, and 2%, respectively.

CONCLUSIONS

The high accuracy, compounded with favorable analytical characteristics, give ProCT great potential to replace calcitonin as a new standard of care in the management of MTC.

Procalcitonin measured by three different assays is an excellent tumor marker for the follow-up of patients with medullary thyroid carcinoma

OBJECTIVES

Procalcitonin (PCT) has been suggested as a tumor marker in patients with medullary thyroid carcinoma (MTC). Clinical application data in long term follow-up are missing.

METHODS

210 serum samples of 169 consecutive patients with MTC (92 sporadic, 77 hereditary, 158 postoperative follow-up, 11 preoperative) were collected between 2018 and 2020. Postoperative patients were stratified into three groups according to their disease status at the end of follow-up: cured (n=51, calcitonin (CT) levels < limit of quantitation), minimal residual disease (n=55, detectable CT and no metastases provable by imaging methods), metastatic disease (n=52). In five patients CT and PCT were measured while on therapy with tyrosine kinase inhibitors (TKI). CT was analyzed by the Roche ECLIA, PCT by three assays from Roche, PES, Abbott.

RESULTS

The mean ± SD values seen with the three PCT assays in the MTC response groups, cured: <0.06, 0.016 ± 0.007, 0.014 ± 0.007 ng/mL, minimal residual disease: 0.511 ± 0.800, 0.389 ± 0.687, 0.341 ± 0.614 ng/mL, metastatic disease 109 ± 202, 60.4 ± 110, 63.3 ± 115 ng/mL correlate well with the CT results in these groups: cured <1.0 pg/mL, minimal residual disease 91.3 ± 121.5 pg/mL, metastatic disease 14,489 ± 30,772 pg/mL. There was a significant correlation (p<0.001) between the three PCT assays (Roche/PES r=0.970, Roche/Abbott r=0.976, Abbott/PES r=0.995). In the course of treatment with TKI both CT and PCT reflected clinical state. Preoperative PCT in hereditary MTC has the same diagnostic validity than CT.

CONCLUSIONS

PCT measured with three different immunoassays is as good as the standard tumor marker CT in the follow-up of MTC but has a superior analytical stability.

Combining Calcitonin and Procalcitonin and Rheumatoid Arthritis-Related Biomarkers Improve Diagnostic Outcomes in Early Rheumatoid Arthritis

Objective

To demonstrate whether procalcitonin (PCT) combined with calcitonin (CT) could provide additional diagnostic value to other clinically available rheumatoid arthritis- (RA-) related biomarkers in the early diagnosis of RA.

Method

The blood samples aseptically collected by venipuncture were centrifuged within 1 hour and frozen at -80°C. PCT and CT levels were measured using electrochemiluminescence immunoassay (ECLIA) in 260 subjects (48 patients with early RA, 34 patients with established RA, 37 patients with systemic lupus erythematosus, 30 with osteoarthritis, 31 with gouty arthritis, and 80 healthy participants). Anti-cyclic citrullinated peptide (Anti-CCP) and anti-RA33 antibodies (Anti-RA33) were analyzed by ELISA. RF was detected by transmission immunoturbidimetry. Mann-Whitney U tests and Kruskal-Wallis tests compared differences among groups. Spearman's rank correlation analysis determined the relationship between biomarkers. Receiver-operator characteristic (ROC) curves were generated, and diagnostic performance was assessed by area under the curve (AUC), as well as specificity, sensitivity, likelihood ratios (LR).

Results

Median serum PCT concentrations were significantly higher (p < 0.0001) in patients with early RA (0.065 ng/ml) when compared with healthy controls (0.024 ng/ml), and patients with osteoarthritis (0.025 ng/ml). When compared with gouty arthritis (GA) controls (0.072 ng/ml) and systemic lupus erythematosus (SLE) controls (0.093 ng/ml), median serum PCT concentrations were not significant in patients with early RA (0.065 ng/ml). Median serum CT concentrations were significantly lower (p < 0.0001) in patients with early RA (0.880 pg/ml) compared with healthy controls (3.159 pg/ml), patients with SLE (2.480 pg/ml), and patients with GA (2.550 pg/ml). When compared with osteoarthritis controls (0.586 pg/ml), median serum CT concentrations were not significant in patients with early RA (0.880 pg/ml). ROC curve analysis comparing early RA with healthy controls demonstrated that the AUC of RF, anti-CCP, and anti-RA33 were 0.66, 0.73, and 0.64, respectively; the additions of PCT and CT further improved the diagnostic ability of early RA with the AUC of 0.97, 0.98, and 0.97, respectively (p < 0.01). The sensitivities of RF, anti-CCP, and anti-RA33 for early RA were 33.33%, 44.74%, and 58.33%, respectively, and the additions of PCT and CT showed very high sensitivities of 83.33%, 92.11%, and 87.50%. The high-value groups of PCT moderately correlated with the anti-RA33 levels (r = 0.417, p < 0.05). CT had no significant correlation with disease duration, radiographic progression, or clinical/serological variables, such as ESR levels, CRP levels, RF, anti-CCP, and anti-RA33 levels in early RA.

Conclusions

Serum PCT and CT combined with clinically available RA-related biomarkers could further improve the diagnostic efficiency of early RA.

Persistence of Elevated Procalcitonin in a Patient with Coronavirus Disease 2019 Uncovered a Diagnosis of Medullary Thyroid Carcinoma

Objective

During the ongoing coronavirus disease 2019 pandemic, procalcitonin (PCT) levels have proven useful in assisting clinicians to diagnose bacterial superinfection. However, in the absence of signs of infection or at the resolution thereof, inappropriately and persistently high PCT levels may suggest and reveal the presence of other pathologies. We report a patient with severe acute respiratory syndrome coronavirus 2 pneumonia with initially elevated PCT levels that persisted during recovery, prompting the diagnosis of medullary thyroid carcinoma (MTC).

Methods

A 43-year-old man presented with a 2-day history of fever, sneezing, sore throat, and dry cough. His PCT was 94 ng/mL (normal value, 0.00-0.10 ng/mL), and he was positive for severe acute respiratory syndrome coronavirus 2 RNA.

Results

Empirical antibiotic therapy was administered for 7 days, but despite a clinical improvement, serum PCT remained high (84 ng/mL). Serum calcitonin (CTN) was 2120 pg/mL (normal, ≤12 pg/mL). Cytologic examination of thyroid nodules and CTN measurement of the aspiration needle washout confirmed MTC. The patient underwent total thyroidectomy with bilateral cervical lymph node dissection. Lowered CTN (986 pg/mL) and PCT (16 ng/mL) levels were observed 48 hours after surgery. A close follow-up was planned following the results of RET gene analysis.

Conclusion

PCT can be a useful biochemical marker of MTC suspicion in patients with inflammatory conditions and persistently elevated PCT, even after resolution. In our case, high levels of PCT in a patient with coronavirus disease 2019 pneumonia without signs of bacterial infection led to MTC diagnosis.

Procalcitonin expression in patients with large cell neuroendocrine carcinoma of the lung

Objective

Procalcitonin (PCT) has received much attention as a serum marker for bacterial infection. Elevated serum PCT is occasionally seen in severe trauma, heatstroke, and neoplastic diseases, including lung cancer with neuroendocrine component.

Results

In the present study, we evaluated PCT expression in the specimen of pulmonary neuroendocrine tumors, comparing large cell neuroendocrine carcinoma (LCNEC), carcinoid, and small cell lung carcinoma (SCLC). Pathological specimens of 10 LCNEC, 4 carcinoid, and 7 SCLC cases were evaluated with immunochemical staining of PCT. Clinical characteristics and serum levels of PCT and C-reactive protein were also evaluated. We observed positive PCT expression in 5 (50%) LCNEC and 2 (50%) carcinoid specimens that were surgically resected. Whereas serum PCT levels were not elevated in patients with PCT-positive carcinoid, two out of three LCNEC patients with high PCT expression in the tumor had elevated serum PCT levels that reflected disease progression. In patients with SCLC, PCT was not detected in the tumor or serum. This is the first immunohistochemical study of the PCT expression in the lung tumor specimens. We concluded that, in patients with LCNEC, high serum PCT levels may be indicative of disease activity and serve as a biomarker.

Myocarditis in SARS-CoV-2 negative patients with suspected preceding infection

SARS-CoV-2 is primarily a respiratory disease; however, there have been multiple reports of associated myocarditis. In our 463 bedded, district general hospital, we noted an influx of young patients with myocarditis shortly after the peak of the outbreak. We report two cases presenting with myocarditis, both of whom tested negative for the virus despite clinical and biochemical evidence of recent infection. Diagnosis was made based on positive transthoracic echocardiogram (TTE) findings and a raised troponin, not in the context of suspected acute coronary syndrome. We recommend that patients with negative coronavirus tests should still be considered at risk of potential sequelae from the disease. There should be a low threshold for performing basic cardiac investigations: ECG, troponin and TTE as well as seeking a cardiology opinion. Colchicine is a recognised treatment for viral pericarditis and should be considered as adjunctive treatment; however, further research is required specific to SARS-CoV-2.

Case Report: Medullary Thyroid Cancer Workup Initiated by Unexpectedly High Procalcitonin Level-Endocrine Training Saves Life in the COVID-19 Unit

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel coronavirus that has caused a worldwide pandemic. The majority of medullary thyroid cancers present as a thyroid nodule. At the time of diagnosis, cervical lymph nodes and distant metastases are frequently detected.

CASE REPORT

Here, we present a case of a 46-year-old man with coronavirus disease (COVID) pneumonia, who had persistently high serum procalcitonin levels despite normal C-reactive protein levels. The attending infectologist happened to be a colleague who spent some time, as part of her internal medicine rotation, in the Endocrine Ward and recalled that medullary thyroid cancer might be the cause. This led to the timely workup and treatment of the medullary cancer.

Basal and Calcium-Stimulated Procalcitonin for the Diagnosis of Medullary Thyroid Cancers: Lights and Shadows

BACKGROUND

Procalcitonin (proCt) was recently proposed as an alternative or in addition to calcitonin (Ct) in medullary thyroid cancer (MTC) diagnostics.

METHODS

Serum basal Ct (bCt) and proCt (bproCt) levels were measured before surgery from a consecutive series of patients with (n=43) and without (n=75) MTC, retrospectively collected in Padua. Serum bproCt, bCt and stimulated proCt and Ct (sproCt and sCt) were measured in another consecutive series of 33 patients seen at three tertiary-level institutions undergoing a calcium stimulation test prior to surgery, 20 of them with a final diagnosis of MTC, and 13 with non-MTC nodular disease.

RESULTS

Median bproCt levels were higher in MTC than in non-MTC. A positive correlation was found for bproCt with bCt (P<0.01, R² = 0.75), and with tumor size (P<0.01, R² = 0.39). The cut-off for bproCt differentiating between MTC and non-MTC patients was >0.07 ng/ml (sensitivity: 85.7%, specificity: 98.9%, positive predictive value [PPV]: 98.2%, negative predictive value [NPV]: 90.6%, P<0.01). While bproCt was >0.07 ng/ml in 38/39 (97.4%) patients with MTC >10 mm, it was above said cut-off only in 15/23 (65.2%) patients with tumors ≤10 mm. A sproCt >0.19 ng/ml was able to identify MTC [sensitivity: 90.0%, specificity:100.0%, PPV: 100.0%, NPV: 86.7% (P<0.01)].

CONCLUSIONS

Our data suggest that bproCt can be a good adjunct to Ct for MTC diagnostic purposes. In consideration of its high specificity, it can be used in combination with Ct in MTC diagnostics, particularly in the case of mildly elevated basal Ct levels.

Clinical performance of calcitonin and procalcitonin Elecsys® immunoassays in patients with medullary thyroid carcinoma

Objectives

Medullary thyroid carcinoma (MTC) is caused by a malignant transformation in the parafollicular C-cells of the thyroid, where calcitonin (CT) is released. Nowadays, CT is the main tumor marker used in the diagnosis and follow-up of MTC patients. Nonetheless, procalcitonin (PCT) has recently been proposed as a useful complementary/alternative biomarker in MTC. Our aims were to investigate the diagnostic performance of CT and PCT and their combination in the differential diagnosis between active and inactive MTC and between MTC and non-MTC thyroid diseases, respectively.

Methods

Serum samples were collected from 16 patients with active (i.e. primary tumour before surgery or post-surgical recurrent disease) and 23 with inactive (i.e. complete remission) MTC, 125 patients with non-MTC benign thyroid disease and 62 patients with non-MTC thyroid cancers, respectively. Elecsys® CT and PCT measurements were simultaneously performed on the Cobas e601 platform (Roche Diagnostics, Rotkreutz, Switzerland).

Results

Both CT and PCT median values in active MTC (94 pmol/L and 1.17 ng/mL, respectively) were significantly higher compared with inactive MTC (0.28 and 0.06) and either benign (0.37 and 0.06) or malignant (0.28 and 0.06) non-MTC. Undetectable PCT was found in five non-MTC patients with false positive CT results.

Conclusions

Elecsys® PCT assay is a highly sensitive and specific alternative MTC marker. At the very least it appears useful in patients with positive CT results as negative PCT values securely exclude active MTC. The availability of both markers on the same automated platform facilitates reflex or reflective strategies to refine the laboratory diagnosis.

Updates in the advances of sporadic medullary thyroid carcinoma: from the molecules to the clinic

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine malignancy that originates in parafollicular cells. It is well-known that a quarter of MTC are involved in hereditary multiple endocrine neoplasia type 2 syndromes, whereas most MTC are sporadic. Unlike the commonly encountered gastrointestinal or pulmonary neuroendocrine tumors, most sporadic MTCs have distinct genetic alterations featured by somatic changes of either Rearranged during Transfection (RET) or RAS point mutation. The increasing application of next-generation sequencing, whole-exome sequencing, and other molecular detection techniques enables us to understand MTC comprehensively concerning its detailed molecular changes and their clinical correlations. This article reviews the advances in genetic alterations and their prognostic impact in sporadic MTC among different populations and discusses the associated tumor immune microenvironments and the potential role of immunotherapy targeting PD-L1/PD-1 in treating MTC. Furthermore, the current multikinase inhibitor targeting therapy for sporadic MTC has been summarized here and its efficacy and drug toxicity are discussed. Updates in advance of the role of calcitonin/procalcitonin/calcitonin-related polypeptide alpha (CALCA) gene transcripts in diagnosing and handling MTC are also mentioned. The treatment of advanced MTC is still challenging and might require a combination of several modalities.

Serum C-reactive protein and procalcitonin values in acute Q fever, scrub typhus, and murine typhus

Background

Although C-reactive protein (CRP) and procalcitonin (PCT) are widely used inflammatory markers for infectious diseases, their role and potential application for rickettsioses were rarely studied.

Methods

A retrospective chart review and serological study were conducted in patients with rickettsioses. The clinical presentations, characteristics, laboratory data, and treatment responses were recorded and their associations with CRP and PCT values were analyzed.

Results

A total of 189 cases of rickettsioses, including 115 cases of acute Q fever (60.8%), 55 cases of scrub typhus (29.1%), and 19 cases of murine typhus (10.1%) were investigated. Both CRP and PCT values increased in the acute phase and declined in the convalescent phase. In the acute phase, mean CRP and PCT values were 78.2 ± 63.7 mg/L and 1.05 ± 1.40 ng/mL, respectively. Percentages of patients falling under different cut-off values of CRP and PCT were calculated systematically. Only 10.8% of CRP was > 150 mg/L and 14.2% of PCT was > 2.0 ng/mL. Patients with delayed responses to doxycycline treatment (> 3 days from treatment to defervescence) had significantly higher CRP values (102.7 ± 77.1 vs. 72.2 ± 58.2 mg/L, p = 0.041) and more PCT > 1.0 ng/ml (48.4% vs. 26.0%, p = 0.019) in the acute phase; higher CRP values (19.1 ± 37.4 vs. 3.6 ± 13.1 mg/L, p = 0.049) and more PCT > 0.5 ng/ml (19.2% vs. 1.4%, p = 0.005) in the convalescent phase. Correlation analysis was conducted for patients with acute Q fever. CRP and PCT values were positively correlated to each other, and both markers also had a positive correlation with serum aspartate transaminase values. Both CRP and PCT values and white blood cell counts were positively correlated to the days needed from doxycycline treatment to defervescence.

Conclusion

CRP and PCT values might be useful in clinical investigations for patients with suspected rickettsioses and in predicting the response to doxycycline treatment for rickettsioses.

Laboratory Testing in Thyroid Conditions - Pitfalls and Clinical Utility

Thyroid disorders are common, affecting more than 10% of people in the US, and laboratory tests are integral in the management of these conditions. The repertoire of thyroid tests includes blood tests for thyroid-stimulating hormone (TSH), free thyroxine, free triiodothyronine, thyroglobulin (Tg), thyroglobulin antibodies (Tg-Ab), thyroid peroxidase antibodies (TPO-Ab), TSH receptor antibodies (TRAb), and calcitonin. TSH and free thyroid hormone tests are frequently used to assess the functional status of the thyroid. TPO-Ab and TRAb tests are used to diagnose Hashimoto's thyroiditis and Graves' disease, respectively. Tg and calcitonin are important tumor markers used in the management of differentiated thyroid carcinoma and medullary thyroid carcinoma (MTC), respectively. Procalcitonin may replace calcitonin as a biomarker for MTC. Apart from understanding normal thyroid physiology, it is important to be familiar with the possible pitfalls and caveats in the use of these tests so that they can be interpreted properly and accurately. When results are discordant, clinicians and laboratorians should be mindful of possible assay interferences and/or the effects of concurrent medications. In addition, thyroid function may appear abnormal in the absence of actual thyroid dysfunction during pregnancy and in critical illness. Hence, it is important to consider the clinical context when interpreting results. This review aims to describe the above-mentioned blood tests used in the diagnosis and management of thyroid disorders, as well as the pitfalls in their interpretation. With due knowledge and care, clinicians and laboratorians will be able to fully appreciate the clinical utility of these important laboratory tests.

Esophageal neuroendocrine carcinoma complicated with unexpected hyperprocalcitonin: Case report and literature review

RATIONALE

Neuroendocrine tumors (NETs) with hyperprocalcitonin are relatively rare with a low incidence rate.

PATIENT CONCERNS

An afebrile 63-year-old male with persistent low back pain unexpectedly presented with an extreme hyperprocalcitonin. Radiological assessment revealed thickening of the esophageal wall with vertebral bone destruction and liver lesions. Endoscopy showed an irregular-shaped esophageal lesion which turned out to be poorly-differentiated NETs.

DIAGNOSIS

Esophageal NETs with multiple metastases.

INTERVENTIONS

The patient was treated with chemotherapies, and was evaluated by procalcitonin level and radiology within follow-up.

OUTCOME

The procalcitonin levels were altered in line with the therapeutic response and disease progression during the treatment course.

LESSONS

Increased procalcitonin occurs in several malignancies with neuroendocrine components, such as NETs of the digestive system.

Procalcitonin (PCT) Predicts Worse Outcome in Patients with Chronic Heart Failure with Reduced Ejection Fraction (HFrEF)

Introduction

Procalcitonin (PCT) is an excellent marker of sepsis but was not extensively studied in cardiology. The present study investigated PCT plasma concentration in patients with chronic heart failure with reduced ejection fraction (HFrEF) and its prognostic value during 24-month follow-up.

Material and Methods

Study group consisted of 130 patients with HFrEF (LVEF ≤ 45%) and 32 controls. PCT level was assessed on admission in all patients. Telephone follow-up was performed every three months over a period of 2 years. Endpoints were death of all causes and readmission for HFrEF exacerbation.

Results

HFrEF patients had significantly higher PCT concentration than controls (166.95 versus 22.15 pg/ml; p < 0.001). Individuals with peripheral oedema had increased PCT comparing to those without oedema (217.07 versus 152.12 pg/ml; p < 0.02). In ROC analysis, PCT turned out to be a valuable diagnostic marker of HFrEF (AUC 0.91; p < 0.001). Kaplan-Meier survival curves revealed that patients with PCT in the 4th quartile had significantly lower probability of survival than those with PCT in the 1st and 2nd quartiles. In univariate, but not multivariate, analysis, procalcitonin turned out to be a significant predictor of death during 24-month follow-up. (HR 1.002; 95% CI 1.000–1.003; p < 0.03).

Conclusions

Elevated PCT concentration may serve as another predictor of worse outcome in patients with HFrEF.

Procalcitonin measurement to screen medullary thyroid carcinoma: A prospective evaluation in a series of 2705 patients with thyroid nodules

BACKGROUND

To prospectively evaluate the role of procalcitonin (PCT) in screening of patients with thyroid nodules for medullary thyroid carcinoma (MTC).

MATERIALS AND METHODS

We measured PCT in 2705 patients with thyroid nodules referred to our centre between January 2011 and December 2017. Those with a positive PCT were operated after positive confirmatory tests such as fine-needle aspiration, measurement of calcitonin (CT) in serum and fine-needle aspiration washouts or CT stimulation testing. Patients with a negative PCT were operated based on the results of further diagnostics. The diagnostic performance of PCT was evaluated, and the best cut-off level was selected by ROC curve analysis.

RESULTS

Among 2705 patients, 9 with positive serum PCT (ie, above 0.1 μg/L) and 370 with negative PCT underwent thyroid surgery. MTC was histologically confirmed in all patients with positive PCT but not found in patients with negative PCT. Serum PCT levels were significantly higher in patients with MTC (median 0.64 μg/L, range 0.16-12.9 μg/L) than in those without (median 0.075 μg/L, range 0.075-0.16 μg/L; P < .0001). ROC curves were plotted to calculate the optimal PCT value separating patients with MTC from those without. The best cut-off was 0.155 μg/L with sensitivity, specificity, positive and negative predictive values as well as accuracy of 100%, 99.7%, 91.7%, 100% and 99.7%, respectively. Positive and negative likelihood ratios were 329 and zero, respectively.

CONCLUSIONS

Measurement of PCT is a sensitive and accurate method for detecting MTC in patients with thyroid nodules and can thus be a reliable alternative to CT measurement.

Procalcitonin as Marker of Recurrent Medullary Thyroid Carcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Calcitonin measurement is pivotal in the management of medullary thyroid carcinoma (MTC), but several pitfalls can affect its reliability. Other potential markers have been proposed, and procalcitonin (ProCT) has been reported as promising. The present study was undertaken to summarize the published data and provide more robust estimates on the reliability of ProCT as marker in the management of patients with MTC.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The sources comprised studies published through May 2018. Journal Articles that reported series of MTC patients undergone ProCT during postoperative follow-up were searched. A random-effects model was used for statistical pooling of the data. The I² index was used to quantify the consistency among the studies. The Egger test evaluated the possible presence of significant publication bias. Quality assessment of the studies was performed according to Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2).

RESULTS

According to inclusion and exclusion criteria five papers, reporting 296 MTC patients undergone ProCT evaluation, were finally selected. The number of MTC with recurrence was 140. The pooled sensitivity of ProCT in detecting recurrence was 96% (95% confidence interval [CI], 92% to 99%), with neither heterogeneity (I²=0%) nor publication bias (Egger test, 3.16; P=0.99). The pooled specificity was 96% (95% CI, 87% to 100%) with mild heterogeneity (I²=66.6%), while Egger test was not calculable.

CONCLUSION

The present meta-analysis provides evidence that ProCT is reliable to manage MTC patients during their postoperative follow-up.

Procalcitonin as a postoperative marker in the follow-up of patients affected by medullary thyroid carcinoma

AIM

Due to the limits of calcitonin, other markers are warranted to better manage medullary thyroid carcinoma patients, and procalcitonin has been reported as promising. Here we aimed to evaluate procalcitonin as a marker of medullary thyroid carcinoma in the post-treatment follow-up.

METHODS

Medullary thyroid carcinoma patients previously treated by thyroidectomy were enrolled. After complete imaging work-up (i.e. ultrasonography, computed tomography, magnetic resonance and ¹⁸FDG-PET-CT) we identified patients with structural recurrent/persistent medullary thyroid carcinoma (active medullary thyroid carcinoma) and subjects with no evidence of disease. Then, both calcitonin and procalcitonin were measured and their performance analyzed.

RESULTS

The final series included 55 medullary thyroid carcinoma patients treated and followed-up for about five years. Of these, 43 were assessed as no evidence of disease, and 12 as active medullary thyroid carcinoma. The median value of procalcitonin was significantly higher ( P < 0.0001) in active medullary thyroid carcinoma patients (3.10 ng/mL) than in those with no evidence of disease (0.10 ng/mL). Also, calcitonin levels of active medullary thyroid carcinoma (96.7 pg/mL) were significantly ( P < 0.0001) higher than that of no evidence of disease (2.0 pg/mL). At the receiver operating characteristic curve analysis, the optimal cut-off of procalcitonin was ≥0.32 ng/mL with 92% sensitivity and 98% specificity, while the most accurate threshold of calcitonin was ≥12.0 pg/mL with 100% sensitivity and 91% specificity. There was no active medullary thyroid carcinoma with simultaneously negative results of procalcitonin and calcitonin.

CONCLUSIONS

Procalcitonin is reliable in discriminating medullary thyroid carcinoma patients with active disease from those with no evidence of disease. We suggest using procalcitonin as complementary to calcitonin to follow-up medullary thyroid carcinoma patients.

Comparison of the prognostic values of selected inflammation based scores in patients with medullary thyroid carcinoma: A pilot study

BACKGROUND

The significance of inflammation based scores including the neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), prognostic nutritional index (PNI), and plasma fibrinogen remains unclear in medullary thyroid carcinoma (MTC). We aimed to compare the prognostic value of these scores.

METHODS

Seventy-eight patients newly diagnosed as MTC with operation in our institution from May 2009 to September 2016 were retrospectively evaluated. Receiver operating characteristic (ROC) curves and Kaplan-Meier analyses were calculated to compare the prognostic value of these scores.

RESULTS

Increased PLR was predictive of lymph node metastasis (AUC = 0.644, P = 0.022), capsule invasion (AUC = 0.666, P = 0.007), advanced tumor stages (AUC = 0.657, P = 0.011), and recurrence (AUC = 0.655, P = 0.049). Increased fibrinogen was predictive of lymph node metastasis (AUC = 0.669, P = 0.006) and capsule invasion (AUC = 0.631, P = 0.038). Reduced PNI was predictive of recurrence (AUC = 0.655, P = 0.049). Kaplan-Meier analyses and Cox regression analysis revealed that PLR was a significant predictor for recurrence.

CONCLUSIONS

PLR, fibrinogen, and PNI are all predictive. Specially, PLR is superior to other inflammation based scores in terms of prognostic ability.

Procalcitonin for detecting medullary thyroid carcinoma: a systematic review

The aim of the present study was to perform a systematic review of published studies to provide a robust estimation of the use of procalcitonin (ProCT) as a diagnostic marker of medullary thyroid carcinoma (MTC), with particular focus on its specificity and negative predictive value in excluding MTC. A comprehensive computer literature search was conducted to find relevant published articles on the topic. We used a search algorithm based on a combination of the terms 'medullary,' 'thyroid,' and 'ProCT.' The search was updated until February 2015. To expand our search, references of the retrieved articles were also screened. A total of 39 articles were retrieved, of which nine original papers published from 2003 to 2014 were selected for the review. Some of these studies used ProCT in the preoperative diagnosis of MTC, whereas others measured ProCT during the follow-up of patients who had been previously treated for MTC. Other laboratory measurements were performed in some of the included studies. The results of the majority of the studies indicate that ProCT measurement appears to be a very promising and reliable serum marker for the diagnosis of MTC, and it is not inferior to calcitonin (CT). The sample handling is less laborious, and in the few CT-negative cases reviewed, the assay had even greater sensitivity. It would be worthwhile to establish cutoff levels using larger patient series, because we speculate that this assay could potentially replace CT measurement in the future.

Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma

INTRODUCTION

The American Thyroid Association appointed a Task Force of experts to revise the original Medullary Thyroid Carcinoma: Management Guidelines of the American Thyroid Association.

METHODS

The Task Force identified relevant articles using a systematic PubMed search, supplemented with additional published materials, and then created evidence-based recommendations, which were set in categories using criteria adapted from the United States Preventive Services Task Force Agency for Healthcare Research and Quality. The original guidelines provided abundant source material and an excellent organizational structure that served as the basis for the current revised document.

RESULTS

The revised guidelines are focused primarily on the diagnosis and treatment of patients with sporadic medullary thyroid carcinoma (MTC) and hereditary MTC.

CONCLUSIONS

The Task Force developed 67 evidence-based recommendations to assist clinicians in the care of patients with MTC. The Task Force considers the recommendations to represent current, rational, and optimal medical practice.

The utility of proadrenomedullin and procalcitonin in comparison to C-reactive protein as predictors of sepsis and bloodstream infections in critically ill patients with cancer*

OBJECTIVES

Infections in critically ill patients continue to impose diagnostic and therapeutic challenges. We seek to investigate the utility of proadrenomedullin and procalcitonin as diagnostic and prognostic biomarkers in febrile critically ill patients with cancer and compare their performance with that of C-reactive protein.

DESIGN

Single-center prospective cohort study.

SETTING

Tertiary care, academic, university hospital.

PATIENTS

One hundred fourteen critically ill patients with cancer with fever.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood samples were withdrawn on the day of fever onset and 4 to 7 days thereafter, and the serum proadrenomedullin, procalcitonin, and C-reactive protein levels were measured using the Kryptor technology afterward. Of the 114 adult patients, 27 had bloodstream infections, 36 had localized infections, and the remaining had no infections. The area under the receiver operating characteristic curve for bloodstream infection diagnosis was significantly greater for proadrenomedullin (0.70; 95% CI, 0.59-0.82) and procalcitonin (0.71; 95% CI, 0.60-0.83) compared with C-reactive protein (0.53; 95% CI, 0.39-0.66) (p = 0.021 and p = 0.003, respectively). Receiver operating characteristic analysis also showed that proadrenomedullin (p = 0.005) and procalcitonin (p = 0.009) each had a better performance than C-reactive protein in predicting patients' mortality within 2 months after their fever onset. Regarding patients' response to antimicrobial therapy, proadrenomedullin, procalcitonin, and C-reactive protein levels all significantly decreased from baseline to follow-up in responders (p ≤ 0.002), whereas only proadrenomedullin level significantly increased in nonresponders (p < 0.0001). In patients with documented infections, proadrenomedullin (0.81; 95% CI, 0.71-0.92) and procalcitonin (0.73; 95% CI, 0.60-0.85) each had a greater area under the curve compared with C-reactive protein (0.59; 95% CI, 0.45-0.73) as for as predicting response (p = 0.004 and p = 0.043, respectively). However, for all febrile patients, proadrenomedullin had a significantly greater area under the curve for predicting favorable response than procalcitonin (p < 0.0001).

CONCLUSION

In critically ill patients with cancer, proadrenomedullin and procalcitonin both have a promising role in predicting bloodstream infections in a manner more helpful than C-reactive protein. These two biomarkers were superior to C-reactive protein in the prognostic analysis of response to antimicrobial therapy for those patients with documented infections. However, proadrenomedullin was superior to procalcitonin in predicting response in all febrile patients and was unique in showing increased levels among nonresponders.

Calcitonin as Biomarker for the Medullary Thyroid Carcinoma

Calcitonin (CTN) is a polypeptide hormone consisting of 32 amino acids with a disulfide bridge between position 1 and 7 that is mainly produced by the C-cells of thyroid gland. The measurement of CTN concentrations in blood reflects C-cell activity and is performed in general by immunoassay methods. However, there are analytical, physiological, pharmacological, and pathological factors that can influence results of serum CTN values. Due to the influence of these factors, there is a high variability in assay-dependent cutoffs used to discriminate between MTC, C-cell hyperplasia (CCH), and the absence of the pathological impairment of C-cells. There is a lot of evidence that the measurement of serum CTN concentrations in patients with thyroid nodules can lead to an earlier diagnosis of MTC or CCH than the exclusive use of imaging procedures and/or fine-needle aspiration cytology. Basal CTN concentrations higher than 60-100 pg/mL are highly indicative for the diagnosis MTC. In the range between cutoff and 60 pg/mL CTN, both MTC and HCC may be a relevant diagnosis. PCT and CTN appear to have a comparable diagnostic capability to diagnose MTCs. However, "positive" PCT values of more than 50 pg/mL may be reached also in subclinical infections and will lead, therefore, to an overdiagnosis of the tumor. Pentagastrin- or calcium-stimulated serum CTN concentrations higher than cutoff values might improve diagnostics of MTC, but the non-availability of the first and the lacking of relevant cutoff values for the second tool favors the use of only basal values currently.

Utility of serum procalcitonin for screening and risk stratification of medullary thyroid cancer

CONTEXT

The clinical utility of procalcitonin has not been demonstrated across the whole spectrum of medullary thyroid cancer (MTC).

OBJECTIVE

This serum biomarker validation study aimed at defining the diagnostic accuracy of procalcitonin for screening and risk stratification of MTC and delineating biochemical thresholds predictive of lymph node involvement in the neck and mediastinum.

DESIGN AND SETTING

This was a retrospective analysis at a tertiary referral center.

PATIENTS

Included in this study were 457 consecutive patients with previously untreated MTC, 112 of whom had procalcitonin and calcitonin serum levels determined before the initial operation.

INTERVENTION

The intervention was compartment-oriented surgery.

MAIN OUTCOME MEASURES

Main outcome measures included primary tumor diameter, extrathyroidal extension, lymph node metastases, distant metastases, and biochemical cure.

RESULTS

Receiver operating characteristics analyses revealed similar diagnostic accuracy for procalcitonin vs the current calcitonin standard, yielding comparable areas under the curve for primary tumors at thresholds of 10 (0.94 vs 0.93) and 40 (0.92 vs 0.84) mm; extrathyroidal extension (0.84 vs 0.83), lymph node metastasis (0.88 vs 0.86), and distant metastasis (0.93 vs 0.91). Lymph node metastases were present in the ipsilateral lateral neck with procalcitonin levels ≤1.0 ng/mL and the ipsilateral central neck with procalcitonin levels ≤0.25 ng/mL. Above a threshold of 1.0 ng/mL, lymph node metastases emerged in the contralateral central and lateral neck and above 5.0 ng/mL also in the upper mediastinum. When procalcitonin levels exceeded 1, 5, 10, and 50 ng/mL, biochemical cure rates declined to no more than 71%, 36%, 23%, and 10%, respectively.

CONCLUSION

Serum procalcitonin, having comparable diagnostic accuracy, has great potential to replace serum calcitonin as a new standard of care in the management of MTC because it does not need to be kept cool on ice or frozen and is easier to manage at the community level.

[Calcitonin: indications and interpretation]

Calcitonin is the sensitive and specific marker of the medullary thyroid cancers. It is a diagnostic, pronostic and follow-up marker. Medullary thyroid cancer is a rare disease representing 4% of the thyroid cancers and occurring in 0.4% of nodular thyroid pathology. The use of sex specific adults normal ranges allows a better interpretation of the moderately elevated calcitonin levels. Hypercalcitoninaemia non due to medullary thyroid cancer are attributed mainly to male sex, tobacco use, overweight, renal failure and other endocrine tumors. CT is associated to carcinoembryonic antigen and possible procalcitonin assays. Calcitonin can be assayed in the wash-out fluid of the fine needle aspiration too. Stimulation tests give poor additional diagnostic information and are about to be abandoned.

Basal and Stimulated Calcitonin and Procalcitonin by Various Assays in Patients with and without Medullary Thyroid Cancer

BACKGROUND

Calcitonin (CT) is a sensitive marker for evaluation of medullary thyroid cancer (MTC). However, CT measurement can vary with assay- and nonassay-dependent factors, and procalcitonin (PCT) measurement has been proposed for evaluating questionable increases in CT.

METHODS

We tested 2 fully automated CT assays (Immulite [IL] and Liaison [LIA]) and 1 nonautomated CT assay (IRMA, Medipan) and compared these results with PCT (Brahms Kryptor). We evaluated preanalytical conditions and PCT cross-reactivity in sera of 437 patients with clinical conditions associated with hypercalcitoninemia. Additionally, we determined the true “nil” CT concentration in 60 thyroidectomized patients and defined CT cutoff concentrations for pentagastrin stimulation testing in 13 chronic kidney disease (CKD) patients and 10 MTC patients.

RESULTS

Markedly decreased CT concentrations were found after storage of sera for &gt;2 h at room temperature and &gt;6 h at 4 °C. Cutoff concentrations for basal and stimulated CT were disease and assay dependent. Proton pump inhibitor therapy was the most frequent reason for increased CT. PCT concentrations were higher in patients with MTC than in patients with CKD without infections (P &lt; 0.001). Whereas IL and LIA demonstrated comparable analytical quality, the IRMA gave increased CT concentrations in nil sera and showed cross-reactivity with PCT in patients with concomitant bacterial infection.

CONCLUSIONS

IL, LIA, and IRMA detected increased CT concentrations in non-MTC patients and discriminated MTC from CKD patients in pentagastrin tests. PCT assessment may be helpful in the diagnostic work-up of increased CT concentrations in questionable clinical circumstances.

Procalcitonin levels predict clinical course and progression-free survival in patients with medullary thyroid cancer

BACKGROUND

Procalcitonin has been well established as an important marker of sepsis and systemic infection. The authors evaluated the diagnostic and predictive value of calcitonin and its prohormone procalcitonin in medullary thyroid cancer.

METHODS

The authors systematically explored the ability of calcitonin and procalcitonin to identify medullary thyroid cancer and predict the endpoints local recurrence and distant metastases, as well as the progression-free survival. Patients with C-cell hyperplasia; patients after thyroidectomy for differentiated thyroid cancer, goiter, or Graves disease; and healthy subjects served as controls. The study was performed in accordance with the Reporting Recommendations for Tumor Marker Prognostic Studies of the National Cancer Institute.

RESULTS

Sixty-nine medullary thyroid cancer patients and 96 controls were included (median observed interval: 10.9 years [range, 1.4-47.5 years]; 981.8 patient-years). The 1-year, 5-year, 10-year, and 20-year recurrence rates were 9%, 34%, 45%, and 56%, respectively. Calcitonin had a higher diagnostic accuracy for detecting medullary thyroid cancer than procalcitonin (area under the curve [AUC], 0.94; 95% confidence interval [95% CI], 0.90-0.99 vs AUC, 0.89; 95% CI, 0.83-0.95 [P = .038]). The procalcitonin:calcitonin ratio predicted disease progression (AUC, 0.63; 95% CI, 0.51-0.75 [P = .036]) and progression-free survival (hazards ratio, 1.49; 95% CI, 1.09-2.04 [P = .013]).

CONCLUSIONS

The results of the current study indicate a superior diagnostic accuracy of calcitonin and an independent predictive value of the procalcitonin:calcitonin ratio. These findings may lead to improved diagnostic and therapeutic strategies for medullary thyroid cancer patients.

Markers of infection in inpatients and outpatients with acute Q-fever

BACKGROUND

Query-fever (Q-fever) is a zoonotic infection caused by the intracellular Gram-negative coccobacillus Coxiella burnetii. A large ongoing outbreak of Q-fever has been reported in the Netherlands. We studied various markers of infection in inpatients (hospitalised) and outpatients (treated by a general physician) with acute Q-fever in relation to disease severity.

METHODS

Leukocyte counts, C-reactive protein (CRP) and procalcitonin (PCT) concentrations were measured in 25 inpatients and 40 outpatients upon presentation with acute Q-fever. Chest X-rays, if available, were analysed and confusion, urea, respiratory rate, blood pressure-age 65 (CURB-65) scores, indicating severity of pneumonia, were calculated.

RESULTS

CRP was the only marker that significantly differentiated between inpatients and outpatients. It was increased in all patients from both groups. Leukocyte counts and PCT concentrations did not differ between inpatients and outpatients. Overall, only 13/65 patients had an increased leukocyte count and only 11/65 patients presented with PCT concentrations indicative of possible bacterial respiratory tract infection. Infiltrative changes on the chest X-ray were observed in the majority of patients. CURB-65 score was 0+/-1 (mean+/-SD).

CONCLUSIONS

Acute Q-fever, a relatively mild pneumonia with low CURB-65 scores, specifically induces a response in CRP, while PCT concentrations and leukocytes are within the normal range or increased only marginally.