A new automated turbidimetric immunoassay for the measurement of canine C-reactive protein

Acute phase proteins in cattle and swine: A review

The major acute phase proteins (APPs) in cattle are haptoglobin (Hp) and serum amyloid A (SAA), and in swine, are Hp, SAA, C-reactive protein (CRP), and Pig major acute phase protein (Pig-MAP). Many methodologic assays are presently available to measure these parameters, which are still being improved to increase their specificity, sensitivity, user-friendliness, and economic availability. In cattle, the main applications are the diagnosis and monitoring of frequent diseases such as mastitis and metritis in dairy cows and respiratory problems in young calves. In pigs, APPs are useful in the control of bacterial and viral infections, and they may be used at the slaughterhouse to monitor subclinical pathologies and improve food safety. The utility of APP in animal production must not be forgotten; optimization of protocols to improve performance, welfare, and nutrition may benefit from the use of APPs. Other sample types besides serum or plasma have potential uses; APP determination in milk is a powerful tool in the control of mastitis, saliva is a non-invasive sample type, and meat juice is easily obtained at the slaughterhouse. Increasing our knowledge of reference intervals and the influence of variables such as age, breed, sex, and the season is important. Finally, worldwide harmonization and standardization of analytical procedures will help to expand the use of APPs.

Validation of new automated turbidimetric immunoassays for the measurement of haptoglobin and inter-α-trypsin inhibitor heavy chain H4 specific for the bovine species

BACKGROUND

Good strategical programs are required for the early detection of disease even in the absence of evident clinical signs, which is crucial in satisfying animal welfare. Haptoglobin (Hp) and inter-α-trypsin inhibitor heavy chain H4 (ITIH4) are acute phase proteins and good biomarkers of early inflammation in cattle, with plasma levels that significantly increase after injury or infection.

OBJECTIVES

We aimed to develop and validate two new immunoturbidimetric methods for Hp and ITIH4.

METHODS

Species-specific antibodies were obtained and used to develop the immunoassays. For the Hp assay, antibodies were fixed to latex microparticles to enhance detection. The immunoassays were set up in an automated analyzer to carry out validation studies. Reference intervals were calculated using Reference Value Advisor.

RESULTS

The Hp immunoturbidimetric method had a linear analytical range up to 0.40 mg/mL. The limit of detection (LoD) was 0.005 mg/mL, and the limit of quantification (LoQ) was 0.007 mg/mL. Total imprecision was less than 7%. Comparison with ELISA and single radial immunodiffusion (SRID) showed good correlation, whereas the comparison with the colorimetric method showed constant and proportional differences. The ITIH4 immunoassay showed linearity up to 5 mg/mL, and the LoD was 0.002 mg/mL. Total imprecision was less than 6%. Method comparison showed a good correlation with single radial immunodiffusion, both methods being equivalent. Bilirubin, triglycerides, and hemoglobin presented no interference in any of the assays. Reference intervals were 0.007-0.017 mg/mL for Hp and 0.2-0.7 mg/mL for ITIH4 in dairy cows 10 days before parturition.

CONCLUSIONS

Immunoturbidimetric methods developed for Hp and ITIH4 can measure basal and increased levels of these proteins, showing adequate precision, accuracy, and robustness.

Validation of an automated immunoturbidimetric assay for feline serum amyloid A

BACKGROUND

Serum Amyloid A (SAA) is a major acute phase protein in cats, increasing rapidly in response to various inflammatory diseases. An automated latex-enhanced immunoturbidimetric assay for human SAA (LZ-SAA, Eiken), previously validated for use in cats, has had further major modification (VET-SAA, Eiken) for specific use in veterinary diagnostic laboratories but has yet to be validated in cats.

RESULTS

Intra-assay and inter-assay CVs for the VET-SAA assay ranged from 1.88-3.57% and 3.98-6.74%, respectively. Linearity under dilution was acceptable with no prozone effect observed. Limit of detection was 1.65 mg/L and limit of quantification was 6 mg/L. Haemoglobin and triglyceride showed no adverse interference, but bilirubin produced positive bias in samples with low SAA. Comparison with the LZ-SAA assay showed significant correlation with proportional bias increasing as SAA concentration increased, likely related to differing calibration standards. SAA was significantly higher in patients with inflammatory disease compared with non-inflammatory disease, and in patients with moderate to highly elevated α1-AGP compared with patients with normal α1-AGP. Improvement of the assay range may be required to fully evaluate differences between disease groups at low SAA levels. Based on ROC curve analysis, at a cut-off point of 20.1 mg/L the VET-SAA assay discriminated between inflammatory and non-inflammatory disease with sensitivity of 0.93 and specificity of 0.99.

CONCLUSIONS

The automated VET-SAA assay is a robust, precise, and accurate method for measurement of feline SAA which can clearly identify patients with inflammatory disease. It should be a valuable biomarker for use in feline medicine.

Canine chronic enteropathy—Current state-of-the-art and emerging concepts

Over the last decade, chronic inflammatory enteropathies (CIE) in dogs have received great attention in the basic and clinical research arena. The 2010 ACVIM Consensus Statement, including guidelines for the diagnostic criteria for canine and feline CIE, was an important milestone to a more standardized approach to patients suspected of a CIE diagnosis. Great strides have been made since understanding the pathogenesis and classification of CIE in dogs, and novel diagnostic and treatment options have evolved. New concepts in the microbiome-host-interaction, metabolic pathways, crosstalk within the mucosal immune system, and extension to the gut-brain axis have emerged. Novel diagnostics have been developed, the clinical utility of which remains to be critically evaluated in the next coming years. New directions are also expected to lead to a larger spectrum of treatment options tailored to the individual patient. This review offers insights into emerging concepts and future directions proposed for further CIE research in dogs for the next decade to come.

Prognosis in metastatic lung cancer: vitamin D deficiency and depression—a cross-sectional analysis

Background

Depression and vitamin D deficiency are common in patients with lung cancer and have prognostic implications in cancer settings. However, their relationship and concomitant survival implications have not been evaluated in patients with metastatic lung cancer specifically. We hypothesised that vitamin D deficiency would be associated with depression and inferior cancer-related survival in patients receiving therapies for stage IV lung cancer.

Methods

This was a cross-sectional analysis of vitamin D, depression and lung cancer characteristics. Vitamin D levels were stratified by level (no deficiency ≥30 units, mild deficiency 20 to 29 units and moderate-to-severe <20 units). Depression was measured by the Hospital Anxiety and Depression Scale-Depression (HADS-D). Survival estimations were made using Cox proportional hazard model and Kaplan-Meier analyses.

Results

Vitamin D deficiency was evident in almost half of the sample (n=98) and was associated with significant depression (HADS-D ≥8) (χ2=4.35, p<0.001) even when controlling for age, sex and inflammation (β=-0.21, p=0.03). Vitamin D deficiency and depression were associated with worse survival and showed evidence of an interaction effect (HR 1.5, p=0.04).

Conclusion

Vitamin D deficiency is associated with depression in patients with metastatic lung cancer. Depression modulates the survival implications of vitamin D deficiency in this population. The role of vitamin D deficiency in cancer-related depression warrants further investigation since both are amenable to treatment. Psychological and nutritional prognostic considerations may help inform treatment paradigms that enhance quality of life and survival.

Antimicrobial discontinuation in dogs with acute aspiration pneumonia based on clinical improvement and normalization of C‐reactive protein concentration

Background

Evidence regarding optimal treatment duration in dogs with aspiration pneumonia (AP) and the role of thoracic radiographs (TXR) and lung ultrasonography (LUS) in the long‐term follow‐up of affected dogs is lacking. C‐reactive protein (CRP) is a reliable acute phase protein to monitor bacterial pneumonia in dogs.

Hypothesis

Investigate the safety of antimicrobial discontinuation based on clinical improvement and serum CRP normalization, as well as the usefulness of TXR and LUS for follow‐up.

Animals

Dogs diagnosed with AP and treated with antimicrobials.

Methods

Prospective observational study. Antimicrobials were discontinued based on clinical improvement and serum CRP normalization after 1, 3, or 5 weeks. At each consultation, a quality‐of‐life questionnaire, physical examination, serum CRP, TXR, and LUS were assessed. Short‐ (2 weeks) and long‐term (>1 month) follow‐ups after treatment discontinuation were performed to monitor for possible relapses.

Results

Seventeen dogs were included. Antimicrobials were discontinued after 1 week in 12 dogs (70.6%) and 3 weeks in the remaining 5 dogs (29.4%). Short‐term relapse was not observed in any dog and long‐term relapse was diagnosed in 3 dogs. Thoracic radiographs and LUS were useful for diagnosis, but did not add additional information during follow‐up, because image normalization lagged behind clinical improvement and serum CRP normalization.

Conclusion and Clinical Importance

Dogs with AP can be safely and effectively treated using a short‐term antimicrobial regimen discontinued after clinical improvement and serum CRP normalization. Imaging might still be useful for complicated cases with a less favorable response to treatment.

Comparison of lung ultrasound, chest radiographs, C-reactive protein, and clinical findings in dogs treated for aspiration pneumonia

Background

Comparison of clinical findings, chest radiographs (CXR), lung ultrasound (LUS) findings, and C‐reactive protein (CRP) concentrations at admission and serial follow‐up in dogs with aspiration pneumonia (AP) is lacking.

Hypothesis

Lung ultrasound lesions in dogs with AP are similar to those described in humans with community‐acquired pneumonia (comAP); the severity of CXR and LUS lesions are similar; normalization of CRP concentration precedes resolution of imaging abnormalities and more closely reflects the clinical improvement of dogs.

Animals

Seventeen dogs with AP.

Methods

Prospective observational study. Clinical examination, CXR, LUS, and CRP measurements performed at admission (n = 17), 2 weeks (n = 13), and 1 month after diagnosis (n = 6). All dogs received antimicrobial therapy. Lung ultrasound and CXR canine aspiration scoring systems used to compare abnormalities.

Results

B‐lines and shred signs with or without bronchograms were identified on LUS in 14 of 17 and 16 of 17, at admission. Chest radiographs and LUS scores differed significantly using both canine AP scoring systems at each time point (18 regions per dog, P < .001). Clinical and CRP normalization occurred in all dogs during follow up. Shred signs disappeared on LUS in all but 1 of 6 dogs at 1 month follow‐up, while B‐lines and CXR abnormalities persisted in 4 of 6 and all dogs, respectively.

Conclusion and Clinical Importance

Lung ultrasound findings resemble those of humans with comAP and differ from CXR findings. Shred signs and high CRP concentrations better reflect clinical findings during serial evaluation of dogs.

Measurement and clinical applications of C-reactive protein in gastrointestinal diseases of dogs

C-reactive protein (CRP) is a positive acute-phase protein, serum concentrations of which increase nonspecifically in response to inflammatory processes of the dog. As such, it can aid in the identification of inflammatory disease and, maybe more importantly, the objective monitoring of disease progression. In dogs, CRP is frequently used to evaluate dogs with gastrointestinal diseases, such as chronic inflammatory enteropathies (also termed idiopathic inflammatory bowel disease), acute pancreatitis, canine parvovirus infection, hepatic disease, acute abdomen, and protein-losing enteropathy. The diversity of the assays available to measure CRP in dogs is nearly as numerous as the diseases in which serum concentrations of this protein are increased. Assay methodologies include laser nephelometric immunoassays, enzyme-linked immunosorbent assays, immunoturbidimetric assays, and time-resolved immunofluorometric assays. While many of these assays are acceptable for clinical use in the dog, the same assay and analyzer should be used to measure a patient's CRP concentration longitudinally. By looking at the uses of CRP in human gastroenterology, including reducing the duration of antibiotic therapy, the veterinary profession can gain insight into novel ways in which serum CRP concentration measurements might be applied in veterinary medicine in the future.

Potential use of albumin and neutrophil-to-lymphocyte ratio to guide the evaluation and treatment of cancer-related depression and anxiety

BACKGROUND

Depression and anxiety are common and associated with inflammation in patients with cancer. Inflammatory indices such as albumin and neutrophil-to-lymphocyte ratio (NLR) obtained from metabolic panels and complete blood counts should be available for mental health professionals treating anxiety and depression at cancer centers. We hypothesized that albumin and NLR extrapolated from non-mental health oncology appointments would be associated with anxiety and depression and drawn close enough to psychiatry visits to be useful for the psycho-oncologist. MATERIALS & METHODS: Depression and anxiety were evaluated in patients (n = 97) referred to a cancer center psychiatric service for depression using the Patient Health Questionnaire-9 and General Anxiety Disorder-7. Albumin concentration and NLR were assessed for timing and correlation strength with anxiety and depression by setting (localized/metastatic cancer).

RESULTS

Most patients (96%) had albumin or NLR available at any time point of which 45% were drawn within one week of the psychiatric appointment. No significant correlations were noted when evaluating localized cancer or NLR exclusively. For patients with metastatic cancer, anxiety and depression were correlated with albumin at any time point (r = -0.28, p < 0.05; r = -0.40, p < 0.01, respectively) and within a week of psychiatry appointment (r = -0.40, p < 0.05; r = -0.68, p < 0.001, respectively). Albumin evaluated within a week predicted 32% of depression score variance (β = -0.63, p = 0.002). Hypoalbuminemia (<3.8 g/ul) was associated with anxiety (χ2 = 4.43, p = 0.04) and depression (χ2 = 11.06, p = 0.001).

CONCLUSION

Hypoalbuminemia in patients with metastatic cancer may help establish the presence or persistence of anxiety, depression, treatment refractoriness, and the use of inflammation in cancer-related psychological symptom management.

Differential acute-phase protein responses in dogs seropositive or seronegative for Neospora caninum

Neospora caninum is one of the most prevalent Apicomplexa parasites that causes abortion in cattle, as it infects dogs as its definitive host, causing subclinical disease or active neosporosis, marked by meningoencephalitis, and myopathies with muscle and neuromuscular signs of disease. This study aimed to evaluate the acute phase protein response in dogs seropositive and seronegative for N. caninum. Serum samples of 72 dogs were tested by an immunofluorescence antibody test using N. caninum NC-1 strain, and the study population was divided into four groups: symptomatic - muscular and/or neuromuscular signs - and seropositive (n = 16); symptomatic and seronegative (n = 9); asymptomatic and seropositive (n = 34); and asymptomatic and seronegative (n = 13). C-reactive protein (CRP) was measured via immunoturbidimetric assay and serum haptoglobin (Hp) via hemoglobin-binding capacity assay. In the symptomatic groups, seropositive dogs had higher levels of Hp, but not CRP, while seronegative dogs had higher CRP levels. There was no difference in CRP concentration in asymptomatic dogs. Dogs with neuromuscular signs had higher concentrations for Hp in the group seropositive. Hp concentration did not differ between dogs seropositive and seronegative dogs for each group. Serum Hp and CRP could not sufficiently alone flag subclinical infections. Measurement of CRP and Hp concentrations could be clinically valuable to the diagnosis of neurological diseases, and their relative change may indicate the stage of the infection, although their sole use is not able to support the diagnosis of canine neosporosis. Further studies are encouraged to evaluate the specific dynamics of acute phase proteins in canine neosporosis. Serum samples of 72 dogs were tested by an immunofluorescence antibody test using N. caninum NC-1 strain, and the study population was divided into four groups: (1) dogs with muscular and/or neuromuscular signs and seropositive for N. caninum; (2) dogs with muscular and/or neuromuscular signs and seronegative for N. caninum; (3) dogs seropositive for N. caninum with no neuromuscular signs; and (4) healthy dogs and seronegative for N. caninum. The study evaluated if N. caninum infection could have pathophysiological changes activating the acute phase response and an increase in the concentration of acute phase proteins in serum.

Tumor Mutation Burden and Depression in Lung Cancer: Association With Inflammation

BACKGROUND

Patients with lung cancer with greater systemic inflammation have higher rates of depression. Tumor mutation burden (TMB) predicts immunotherapy response in patients with lung cancer and is associated with intratumoral inflammation, which may contribute to systemic inflammation and depression. This study evaluated whether higher TMB was associated with increased depression and systemic inflammation in patients with lung cancer.

PATIENTS AND METHODS

Patients with metastatic lung cancers were evaluated for depression severity using the Hospital Anxiety and Depression Scale. TMB was measured using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets. Inflammation was evaluated using C-reactive protein (CRP) level and neutrophil-to-lymphocyte ratio (NLR).

RESULTS

A total of 96 patients with adequate TMB testing were evaluated. The average number of mutations (TMB) was 10.8 (SD, 10.9). A total of 19% of patients endorsed clinically significant depression symptoms. TMB was significantly correlated with depression severity (r = 0.34; P=.001) and NLR (r = 0.37; P=.002) but not CRP level (r = 0.19; P=.07). TMB was also higher in patients receiving chemotherapy (mean, 12.0) and immunotherapy (mean, 14.4) versus targeted therapy (mean, 4.8). A multivariate model found that TMB (β = 0.30; P=.01) and CRP level (β = 0.31; P=.01) were independently associated with depression; there was no significant interaction effect of TMB × CRP and depression. A similar multivariate model showed no independent effect for NLR and depression (β = 0.16; P=.17) after accounting for TMB.

CONCLUSIONS

These data provide evidence for biologic depression risk in patients with lung cancer who have high levels of TMB. The underlying mechanism of the association is not clearly related to inflammation but warrants further analysis to broadly elucidate the mechanism of biologically derived depression in cancer.

The Sickness Behavior Inventory-Revised: Sickness behavior and its associations with depression and inflammation in patients with metastatic lung cancer

BACKGROUND

Inflammation may contribute to the high prevalence of depressive symptoms seen in lung cancer. "Sickness behavior" is a cluster of symptoms induced by inflammation that are similar but distinct from depressive symptoms. The Sickness Behavior Inventory-Revised (SBI-R) was developed to measure sickness behavior. We hypothesized that the SBI-R would demonstrate adequate psychometric properties in association with inflammation.

METHOD

Participants with stage IV lung cancer (n = 92) were evaluated for sickness behavior using the SBI-R. Concomitant assessments were made of depression (Patient Hospital Questionniare-9, Hospital Anxiety and Depression Scale) and inflammation [C-reactive protein (CRP)]. Classical test theory (CTT) was applied and multivariate models were created to explain SBI-R associations with depression and inflammation. Factor Analysis was also used to identify the underlying factor structure of the hypothesized construct of sickness behavior. A longitudinal analysis was conducted for a subset of participants.

RESULTS

The sample mean for the 12-item SBI-R was 8.3 (6.7) with a range from 0 to 33. The SBI-R demonstrated adequate internal consistency with a Cronbach's coefficient of 0.85, which did not increase by more than 0.01 with any single-item removal. This analysis examined factor loadings onto a single factor extracted using the principle components method. Eleven items had factor loadings that exceeded 0.40. SBI-R total scores were significantly correlated with depressive symptoms (r = 0.78, p < 0.001) and CRP (r = 0.47, p < 0.001). Multivariate analyses revealed that inflammation and depressive symptoms explained 67% of SBI-R variance.

SIGNIFICANCE OF RESULTS

The SBI-R demonstrated adequate reliability and construct validity in this patient population with metastatic lung cancer. The observed findings suggest that the SBI-R can meaningfully capture the presence of sickness behavior and may facilitate a greater understanding of inflammatory depression.

Measurement of ITIH4 and Hp levels in bitches with pyometra using newly developed ELISA methods

Measurement of acute phase proteins (APPs) as biomarkers in canine medicine is in increasing demand. In the present study, the development and validation of two ELISA methods for the quantification of canine inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) and haptoglobin (Hp) are shown. The adequate imprecision and accuracy and wide analytical range make the developed methods appropriate to quantify ITIH4 and Hp in serum samples. The inter- and intra-assay CVs were lower than 10 %, and the assays maintained linearity under dilution and showed analytical equivalence with the method of radial immunodiffusion. The measurement of CRP, Hp and ITIH4 in sera from bitches affected by pyometra allowed us to determine that ITIH4 behaves as a moderate APP in dogs. The group of bitches affected by pyometra showed very high levels of CRP (147 ± 91 mg/L), corresponding to a strong inflammatory process, which resulted in a moderate increase in the concentrations of Hp (7 times) and ITIH4 (3 times) compared to the control group.

Prognostic implications of depression and inflammation in patients with metastatic lung cancer

Background: Lung cancer-related inflammation is associated with depression. Both elevated inflammation and depression are associated with worse survival. However, outcomes of patients with concomitant depression and elevated inflammation are not known. Materials & methods: Patients with metastatic lung cancer (n = 123) were evaluated for depression and inflammation. Kaplan-Meier plots and Cox proportional hazard models provided survival estimations. Results: Estimated survival was 515 days for the cohort and 323 days for patients with depression (hazard ratio: 1.12; 95% CI: 1.05-1.179), 356 days for patients with elevated inflammation (hazard ratio: 2.85, 95% CI: 1.856-4.388), and 307 days with both (χ2 = 12.546; p < 0.001]). Conclusion: Depression and inflammation are independently associated with inferior survival. Survival worsened by inflammation is mediated by depression-a treatable risk factor.

Early childhood adversity in adult patients with metastatic lung cancer: Cross-sectional analysis of symptom burden and inflammation

OBJECTIVE

Psychological and physical symptoms commonly occur in patients with metastatic lung cancer and are associated with reduced quality of life and decreased survival. Previous work has associated these symptoms with inflammation. The experience of Early Childhood Adversity (ECA) is linked to chronic inflammation and may identify adult cancer patients who are at-risk for psychological and physical symptoms. We thus hypothesized that ECA in lung cancer patients would be associated with increased psychological symptoms (distress, anxiety, and depression) and physical symptoms and that this relationship would be explained by inflammation.

METHODS

Patients with metastatic lung cancer (n = 92) were evaluated for ECA using the Risky Families Questionnaire. Concomitant assessments were made of distress (Distress Thermometer and Problem List [DT&PL]), anxiety (Generalized Anxiety Disorder-7), depression (Patient Hospital Questionniare-9), physical symptoms (DT&PL), and inflammation (C-reactive protein [CRP]). Multivariate models were created to explain associations of ECA with depression, anxiety, distress, number of physical problems, and inflammation.

RESULTS

ECA was associated with distress (r = 0.24, p = .03), anxiety (r = 0.30, p = .004), depression (r = 0.35, p = .001), greater physical problems (r = 0.25, p = .03), younger age (r = -0.29, p = .006), and elevated CRP (r = 0.22, p = .04). Multivariate analyses of outcomes found that depression severity was independently explained by both ECA and inflammation (β = 0.37, p = .001) but not distress or anxiety, while controlling for age and sex. Number of physical problems were also associated with ECA (β = 0.35, p = .004) but not inflammation. The association between ECA and physical problems was not significant after controlling for depression.

CONCLUSION

ECA is associated with increased depression and physical symptoms independent of inflammation. Moreover, depression appears to mediate the impact of ECA on physical symptoms. ECA may identify patients at risk for psychological and physical symptoms.

Evaluation of an automated immunoturbidimetric assay for detecting canine C-reactive protein

C-reactive protein (CRP) is a major acute-phase protein, and it is produced by the liver in response to a pro-inflammatory stimulus. Given that human and canine CRP have a similar molecular structure, the assays used for human CRP detection have been used to measure CRP concentrations in dogs. We evaluated the use of a human CRP assay (Biotecnica CRP assay) and validated its application in dogs. We analyzed 91 canine serum samples with a fully automated analyzer. Our validation was based on the evaluation of imprecision, limits of linearity, limits of quantification, and an evaluation of interferences. The new assay was also compared with the Randox CRP assay, a validated assay for the measurement of CRP. Intra- and inter-assay repeatability were <8% and <11%, respectively. The tested assay proportionally measured canine CRP in an analytical range up to 60 mg/L; however, hemoglobin, triglycerides, and bilirubin interfered with the determination. Good agreement, with the presence of proportional systematic bias, was observed between Biotecnica and Randox assays. The Biotecnica CRP assay provides reliable measurement of CRP in canine serum, provided that samples are free of interferents.

A Longitudinal Analysis of Inflammation and Depression in Patients With Metastatic Lung Cancer: Associations With Survival

BACKGROUND

Depression and inflammation are concomitantly elevated in patients with lung cancer and may have collective survival implications. However, the longitudinal relationship between depression and inflammation in patients with metastatic lung cancer is not fully appreciated. We hypothesized that longitudinal changes in inflammation and depression would be concordant; that longitudinally elevated inflammation would lead to greater depression over time; and that depression with inflammation would be more persistent than depression without inflammation.

METHODS

Patients with metastatic lung cancer (n = 68) were assessed for clinically significant depression (Hospital Anxiety and Depression Scale ≥ 8) and inflammation (C-Reactive Protein ≥ 1 mg/L) along with demographic variables. Survival estimations were made using Cox Proportional Hazard Model and Kaplan-Meier plot analyses.

RESULTS

At baseline (T1), 15% had depression and 35% had increased inflammation followed by 18% with depression and 38% with increased inflammation 4.7 months later (T2). The odds ratio of depression in the presence of clinically significant inflammation was 4.8 at T1 and 5.3 at T2. Between time points, inflammation difference correlated with depression difference (r = -.26, p = .03). Significant depression at both time points was associated with a 4 fold risk of inferior survival while significant inflammation at any time point was associated with >3 fold risk of inferior survival.

CONCLUSIONS

Depression and inflammation track together over time and have variable implications on survival. Persistent depression is particularly detrimental but incidental inflammation is more sensitive to predicting poor survival. These findings have implications for treating depression early in the lung cancer trajectory.

Depression and Inflammation in Patients With Lung Cancer: A Comparative Analysis of Acute Phase Reactant Inflammatory Markers

BACKGROUND

Depression and inflammation are intertwined, which is particularly relevant for patients with lung cancer who have an abundance of inflammation and experience depression. Acute phase reactants (APRs), albumin and C-reactive protein (CRP), are easily interpretable indirect markers of inflammation that have never been concomitantly compared with depression. Inflammation increases CRP (positive APR) and decreases albumin (negative APR). We hypothesize that albumin will be similarly associated with depression, thereby helping to inform the diagnosis of inflammatory depression.

OBJECTIVE

Compares the relationship between depression and representative positive and negative acute phase reactants in patients with metastatic lung cancer.

METHODS

Patients (n = 109) with metastatic lung cancer were evaluated for depression using the Hospital Anxiety and Depression Scale. Inflammation as measured by positive (CRP) and negative (albumin) APRs along with demographic and treatment variables were analyzed for associations with depression.

RESULTS

Depression was associated with lower albumin (r = -0.35, P < 0.001), higher CRP (r = 0.47, P < 0.001), and the CRP/albumin ratio (r = 0.45, P < 0.001). Hierarchical linear regression modeling found that albumin was associated with depression when controlling for demographics, disease, and treatment types (β = -0.28, P = 0.01). When both APRs were in the model, only CRP predicted depression (β = 0.31, P = 0.01), and albumin did not moderate CRP and depression. CRP/albumin ratio did not add to understanding depression variability, but patients with both low albumin and high CRP had particularly severe depression.

CONCLUSION

Albumin is associated with depression but not to a greater extent than CRP. The coupling of lower albumin and higher CRP describes more severe depression. Positive and negative APRs may form a distinct biologic signature to help identify patients with inflammatory depression in the lung cancer setting.

Neutrophil to Lymphocyte Ratio in Lung Cancer: Implications for Depressive Symptoms and Survival

Background:

Depression very commonly appears in the presence of lung cancer. Multiple contexts have shown that depression is associated with inflammation. The Neutrophil to Lymphocyte Ratio (NLR) provides an easy to interpret the measure of both inflammation and immunity, but its use as an inflammatory biomarker has not been evaluated in patients with lung cancer. We hypothesize that NLR will be elevated in depressed patients with lung cancer and that both elevated NRL and depression will have prognostic implications.

Methods:

Patients (n=109) were assessed for depression and anxiety using the Hospital .Anxiety and Depression Scale (HADS) and for distress using the Distress Thermometer. NLR was derived from a complete blood count obtained on the day of the cross-sectional survey. Data were dichotomized (NLR ≥5 and HADS-D ≥8) and analysed for survival estimations using Kaplan-Meier plots.

Results:

NLR was found to be significantly correlated with depression (r=.21, p=.03) and was associated with depression while controlling for age, sex, and marital status (β=.21, p=.004). NLR trended toward correlation with anxiety (r=.19, p=.07). Elevated NLR (≥5) predicted for worse survival (chi square= 10.08, p=.001), which was similarly seen when combined with meeting depression criteria (chi square = 16.00,p<.001).

Conclusion:

NLR provides a reasonable assessment of lung cancer related inflammation with survival implications that may indicate the presence of depression. These results warrant further research.

Analytical validation of an enzyme-linked immunosorbent assay for the quantification of S100A12 in the serum and feces of cats

BACKGROUND

Measuring S100A12 concentrations in serum and feces is a sensitive and specific marker of inflammation, such as seen with chronic gastrointestinal inflammation in people and dogs. Biomarkers of inflammation in cats are currently lacking.

OBJECTIVES

We aimed to analytically cross-validate the canine S100A12-ELISA for the measurement of S100A12 in feline specimens.

METHODS

The ELISA was analytically validated by assessing dilutional linearity, spiking/recovery, intra- and inter-assay variability. Reference intervals for serum and fecal feline S100A12 concentrations were calculated using samples from healthy cats, and the short-term biological variation of fecal S100A12 was assessed.

RESULTS

Observed-to-expected ratios (O/E) for serial dilutions of serum and fecal extracts ranged from 91%-159% (mean, 120%) and 100%-128% (mean, 114%), and for the spiking/recovery method ranged from 106%-263% (mean, 154%) and 52%-171% (mean, 112%). Intra- and inter-assay CV% for serum were ≤5.6% and ≤14.0%, and for fecal extracts were ≤3.8% and ≤19.1%, repsectively. RIs for feline serum and fecal S100A12 concentrations were <43 µg/L and < 20 ng/g, respectively. A mild short-term biologic variation, but large individuality were detected when measuring fecal S100A12 concentrations in healthy cats.

CONCLUSIONS

The canine S100A12-ELISA is accurate, reproducible, and sufficiently linear and precise for the measurement of S100A12 in feline serum and fecal samples. The use of this assay is a reasonable option for the measurement of S100A12 concentrations in feline specimens and provides a basis for the further evaluation of  S100A12 in cats with gastrointestinal disease. Using a population-based RI for fecal feline S100A12 appears to be of limited value.

Depression and inflammation among epidermal growth factor receptor (EGFR) mutant nonsmall cell lung cancer patients

OBJECTIVE

Depression is highly prevalent in nonsmall cell lung cancer (NSCLC) and is associated with elevated inflammation. However, certain subtypes of driver mutation-associated NSCLC such as epidermal growth factor receptor (EGFR)-mutated NSCLC may be associated with less depression given the differences in their underlying biology and disease trajectories. Biological variables such as inflammation, measured by C-reactive protein (CRP), may provide insight into depression variability in EGFR mutant NSCLC.

METHODS

Patients with EGFR mutant and wild-type metastatic NSCLC were evaluated for depression using the Hospital Anxiety and Depression Scale (HADS) on a continuous scale and meeting depression screening criteria (HADS ≥ 8). Inflammation was measured using CRP. A mediation model was created to understand how inflammation mediates EGFR wild-type associated depression.

RESULTS

One hundred out of 120 patients with NSCLC were recruited (83.3% response rate). The 20 participants with EGFR mutant NSCLC had less depression (HADS-D 3.0 versus 5.4) (P < .001), met depression screening criteria less often (P = .047), and exhibited less inflammation (CRP = 0.23 mg/mL versus 2.71 mg/mL) (P < .001) in comparison with EGFR wild-type NSCLC. Multivariate linear regression model revealed that only CRP predicted depression (P = .015) while controlling for age and sex. Mediation analysis found that lower CRP partially mediated less depression in EGFR mutant NSCLC.

CONCLUSIONS

EGFR mutant NSCLC is associated with less depression but the relationship is partially mediated by lower CRP-related inflammation, which is a stronger predictor of depression than EGFR status. Depression in lung cancer varies by subtype and is significantly related to inflammation.

Self-Assembly of Functional Nucleic Acid-Based Colorimetric Competition Assay for the Detection of Immunoglobulin E

In this work, we have developed a simple and rapid colorimetric assay for the detection of immunoglobulin E (IgE) using functional nucleic acids (FNAs) and a solid-phase competition enzyme-linked immunosorbent assay (ELISA). The FNAs including aptamer of recombinant IgE, G-quadruplex and its complementary fragments were immobilized on 96-well microplates to achieve recognition and detection of IgE in biological samples. The G-quadruplex DNAzyme catalyzed 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS)-hemin-H2O2 system was used to improve the sensitivity of colorimetric assay. In the presence of IgE, the hairpin structure and G-quadruplex would be destroyed, resulting in the inactivation of DNAzyme and subsequent reduction of its absorbance. This cost-effective approach detected IgE in the linear range from 5.0 pg/mL to 500 ng/mL, with the limit of detection (LOD) of 2.0 pg/mL, under optimal conditions. Moreover, the developed method was successfully applied to the rapid detection of IgE in human urine, indicating a great potentiality of this approach in clinical diagnosis and other biomedical applications.

New lung cancer treatments (immunotherapy and targeted therapies) and their associations with depression and other psychological side effects as compared to chemotherapy

OBJECTIVE

Lung cancer carries a high prevalence of distress, anxiety and depression. New treatments, targeted therapy and immunotherapy have changed the disease course for subsets of patients and confer longer survival, but their psychological associations and possible mechanisms (e.g., inflammation and physical symptoms) are not well described.

METHOD

Patients with metastatic lung cancer undergoing systemic treatment (n = 109) were evaluated for distress, self-endorsed problems using the Distress Thermometer and Problem List, and depression and anxiety using the Hospital Anxiety and Depression Scale. Demography, cancer-related information, and inflammation were evaluated for their associations with chemotherapy, targeted therapy, and immunotherapy. Inflammation was measured by C-reactive protein, albumin, and neutrophil to lymphocyte ratio.

RESULTS

Chemotherapies were given most often followed by immunotherapy and targeted therapies. Depression and anxiety were endorsed by 23.9%, respectively, and 41.1% had significant distress. Chemotherapy was associated with depression (p = .006) and inflammation (p < .001). Physical symptoms were the same among treatment types. Targeted therapy and immunotherapy predicted for less depression (p = .04, p = .04 respectively) than chemotherapy when controlling for age, sex, and performance status however these predictors where not significant when controlled for inflammation.

CONCLUSION

New immunotherapy and targeted therapies are associated with less depression and inflammation among patients who are living longer while their physical symptoms are the same.

C-reactive protein and its association with depression in patients receiving treatment for metastatic lung cancer

BACKGROUND

Depression is highly prevalent in lung cancer. Although there is a known association between inflammation and depression, this relationship has not been examined in patients with lung cancer who undergo treatment with immune and other targeted drug therapies. Peripheral blood C-reactive protein (CRP), a marker of systemic inflammation, may help identify metastatic lung cancer patients with inflammation-associated depression.

METHOD

Patients with metastatic lung cancer undergoing treatment were evaluated for depression using the Hospital Anxiety and Depression Scale (HADS). Inflammation (CRP and CRP cutoffs ≥1 and ≥3 mg/mL) and demographic and treatment variables were analyzed for association with depression.

RESULTS

One hundred nine consecutive participants exhibited an average plasma CRP concentration of 1.79 mg/mL (median, 0.75 mg/mL [standard deviation, 2.5 mg/mL), and 20.7% had a CRP concentration of ≥3.0 mg/mL; 23.9% met depression screening criteria (HADS ≥8). A log transformation of CRP was significantly correlated with depression severity (r = 0.47, P < .001). CRP was the only covariate to predict depression severity (P = .008) in a multivariate model including lung cancer disease subtype and type of systemic treatment. Receiver operating characteristic analysis indicated that CRP had moderate predictive accuracy in identifying elevated depression (area under the curve = 0.74). A cutoff of CRP ≥3.0 generated high specificity (88%) but identified only 50% of those with elevated depression.

CONCLUSION

Elevated CRP is associated with depression in patients with metastatic lung cancer. Thus, CRP may identify a subset of lung cancer patients with inflammation-induced depression and may be useful in predicting response to treatments that target inflammation or its downstream mediators on the brain.

An immunoturbidimetric assay for bovine haptoglobin

In cattle, the serum protein haptoglobin (Hp) is a major acute phase protein (APP) that rises in concentration over a thousand fold following stimulation by pro-inflammatory cytokines. As such, this APP is a valuable biomarker for infection, inflammation and trauma in cattle. The assay for bovine Hp is becoming more commonplace in clinical pathology and in experimental studies when a biomarker of innate immunity is required. The most widely used assay for Hp utilises its binding to haemoglobin (Hp-Hb binding assay), which at low pH enables the preservation of the native peroxidase activity in the haemoglobin. This assay is used for all species, including species such as dog, cat and pig where the level of Hp is higher in healthy animals of these species than in healthy cattle, and therefore a bovine-specific immunoassay that can be automated would be desirable. Thus, a novel-automated species-specific immunoturbidimetric (IT) assay has been developed. Validation studies showed intra- and inter-assay CVs of below 5% and 9% respectively and a recovery of 99% from samples spiked with bovine Hp and a limit of quantification of 0.033 g/L. The assay is not affected by icterus or lipaemia but had moderate interference from haemoglobin and showed a significant correlation with the Hp-Hb binding assay. This novel IT assay for bovine Hp will allow automated analysis of this important bovine APP to identify changes in the Hp concentration not detectable by current Hp-Hb binding assays. It will enable the incorporation of this assay into herd health assessments, animal welfare analysis and for bovine medicine and research.

Clinical utility of currently available biomarkers in inflammatory enteropathies of dogs

Chronic inflammatory enteropathies (CIE) in dogs are a group of disorders that are characterized by chronic persistent or recurrent signs of gastrointestinal disease and histologic evidence of mucosal inflammation. These CIEs are classified as either food-responsive, antibiotic-responsive, or immunosuppressant-responsive enteropathy. Patients not clinically responding to immunomodulatory treatment are grouped as nonresponsive enteropathy and dogs with intestinal protein loss as protein-losing enteropathy. Disease-independent clinical scoring systems were established in dogs for assessment of clinical disease severity and patient monitoring during treatment. Histopathologic and routine clinicopathologic findings are usually not able to distinguish the subgroups of CIE. Treatment trials are often lengthy and further diagnostic tests are usually at least minimally invasive. Biomarkers that can aid in defining the presence of disease, site of origin, severity of the disease process, response to treatment, or a combination of these would be clinically useful in dogs with CIE. This article summarizes the following biomarkers that have been evaluated in dogs with CIE during the last decade, and critically evaluates their potential clinical utility in dogs with CIE: functional biomarkers (cobalamin, methylmalonic acid, folate, α1 -proteinase inhibitor, immunoglobulin A), biochemical biomarkers (C-reactive protein, perinuclear anti-neutrophilic cytoplasmic antibodies, 3-bromotyrosine, N-methylhistamine, calprotectin, S100A12, soluble receptor of advanced glycation end products, cytokines and chemokines, alkaline phosphatase), microbiomic biomarkers (microbiome changes, dysbiosis index), metabolomic biomarkers (serum metabolome), genetic biomarkers (genomic markers, gene expression changes), and cellular biomarkers (regulatory T cells). In addition, important performance criteria of diagnostic tests are briefly reviewed.