Evaluation of the blood neutrophil-to-lymphocyte ratio as a biomarker for meningoencephalitis of unknown etiology in dogs

Neutrophil-to-Lymphocyte Ratio as a Potential Predictive Marker for Epileptic Seizures: Unveiling the "V"-Shaped Link

Objective: The neutrophil-to-lymphocyte ratio (NLR) is an important marker of inflammation. An increased NLR has been detected in the blood of patients with epilepsy. However, the correlation between varying NLRs and epileptic seizures (ESs) is still unclear. Methods: A retrospective analysis was conducted, and patients were divided into two groups based on whether they had ES upon admission. Comprehensive data were collected, including routine blood tests, demographic information, and medical histories. The NLR was calculated by dividing the percentage of neutrophils by the percentage of lymphocytes. Results: In total, 414 patients were included (284 males, 151 females; aged 18-90 years), with 271 in the experimental group and 143 in the control group. No significant differences in the NLR were found between the groups (p=0.164). Nonetheless, when NLRs were categorized, a "V"-shaped link with ES was observed. An NLR of 2-3 correlated with the lowest seizure incidence. Higher NLRs were associated with increased neutrophil and decreased lymphocyte counts. Patients with an NLR < 2 had the lowest infection rates and the highest cerebrovascular disease exposure, whereas those with an NLR > 3 had the highest infection rates and were the oldest. Conclusions: NLR modifications can serve as potential predictive markers for ES. However, the relationship between the NLR and ES is not linear. The factors contributing to these variations are multiple and complex. An NLR of 2-3 may represent an equilibrium point. An elevated NLR indicates pronounced inflammatory responses, while a low NLR can have more complex causes.

Hematological Markers to Predict Enterectomy Versus Enterotomy in Dogs with Foreign-Body Intestinal Obstruction: Preliminary Data

Intestinal obstruction caused by a foreign body accounts for 80% of all canine intestinal blockages [...].

Evaluation of the covariation between leukotriene B4, prostaglandin E2, and hematologic inflammatory parameters in a canine pentylenetetrazole-induced seizure model

Background

Seizures can cause as well as result from neuroinflammation. This study was performed to identify the hematologic inflammatory parameters (HIPs) and inflammatory mediators that change after a single seizure in a canine pentylenetetrazole (PTZ)-induced seizure model.

Methods

Five healthy Beagle dogs were used in this study. A 3% solution of PTZ was infused until the occurrence of generalized convulsion. Two separate experiments were conducted to observe changes in HIPs over short and long time periods. Blood sampling time points were divided into two periods as follows: short period (baseline, 30, 60, 90, and 120 min after seizure induction) and long period (baseline, 2, 6, 12, 24, and 48 h after seizure induction). The HIPs were calculated, and the serum prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) concentrations were estimated using enzyme-linked immunosorbent assay.

Results

Significant changes (p < 0.05) in various HIPs were observed at different time point as follows: neutrophil × monocyte (90 min), neutrophil-to-lymphocyte ratio (60, 90, and 120 min), lymphocyte to monocyte ratio (60 min, 90 min, 120 min, 2 h, 12 h, and 24 h), platelet-to-albumin ratio (90 min), lymphocyte percentage × serum albumin concentration (LA; 60 min, 90 min, 120 min, 2 h), and neutrophil × platelet (6 h). LTB4 concentrations were significantly increased (p < 0.05) at 60 and 90 min, and 2, 6, and 48 h after seizure induction. PGE2 was significantly increased only 6 h after seizure induction (p < 0.05). LA was one of the HIPs that demonstrated a correlation with LTB4 concentration and showed significant changes that could be observed for a long-period (p < 0.05, r = -0.4194).

Conclusion

The LA was the only HIP that reflected seizure-associated neuroinflammation. The 5-lipoxygenase pathway might be related to seizure-associated neuroinflammation.

Determination of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and systemic immune-inflammation index in dogs with leptospirosis

Leptospirosis is a globally distributed zoonosis with multisystemic involvement in canine species, capable of causing a pulmonary hemorrhagic syndrome (LPHS) in the most severe cases. In humans, the neutrophil to lymphocyte ratio (NLR), platelets to lymphocytes (PLR) and systemic immune-inflammation index (SII) have been described as predictors of morbidity and mortality in various pathologies, but no such studies have been developed for canine leptospirosis. Hence, we aimed to assess the usefulness of NLR, PLR and SII in dogs affected with leptospirosis, focusing on those that died or survived after hospitalization, whether or not they developed LPHS. The leptospirosis group was composed by 36 dogs while the control group consisted of 32 healthy dogs. The NLR, associated with inflammation, demonstrated a threefold or greater increase in all leptospirosis groups compared to the control group (median 2.44 ± 1.66) (developing or not LPHS). Dogs that died (median 67.78 ± 158.67), developed LHPS (median 85.17 ± 143.77), or both developed LHPS and died (median 67.78 ± 155,14) had a lower PLR in comparison to the control group (median 101,82 ± 53,75) and the rest of groups, but no statistically significant differences were observed (p > 0.05). The SII was higher in leptospirosis-affected dogs that survived (median 1356,92 ± 2726,29) and statistically significant differences were observed in those who did not develop LPHS (median 1770,41 ± 2630,77; p < 0.05) compared to the control group (median 555,21 ± 313,26). Our data shows that NLR may be used as inflammation indicator, while more studies are needed for PLR and SII in canine leptospirosis.

Evaluation of Haematological Ratios at: Different Stages of Canine Periodontal Disease

This is a retrospective study about haematological ratios in different stages of canine periodontal disease in one single breed, more specifically the Portuguese Podengo. The aim of the study was to assess the clinical significance of five haematological ratios, namely neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume-to-platelet count ratio (MPV/PLT), monocyte-to-lymphocyte ratio (MLR), and platelet-to-neutrophil ratio (PNR), easily obtained through the parameters provided by the complete blood count, in the stages of gingivitis and periodontitis, compared to clinical healthy individuals. Receiver operating characteristic curves were generated to identify ideal sensitivity and specificity cut-offs for cases of gingivitis or periodontitis. Our study included 80 dogs, which comprised 24 healthy dogs, 26 diagnosed with gingivitis, and 30 with periodontitis. The median NLR was significantly lower in periodontitis than in clinical healthy dogs (p = 0.040) and in dogs with gingivitis (p = 0.037). The median PLR was significantly lower in cases of gingivitis (p = 0.020) and periodontitis (p = 0.024) than in healthy dogs. MPV/PLT and MLR did not demonstrate significant differences between any of the three groups. The median PNR was significantly lower in gingivitis than in control dogs (p = 0.019). PNR had the highest accurate results, in distinguishing between healthy individuals and those with gingivitis, with an area under the curve of 0.692 (95% CI [0.539-0.845], p = 0.020). However, even this index had weak discriminatory power between the groups in the analysis. The impact of systemic inflammation generated by canine periodontal disease can thus be seen through some of these indices. However, the results obtained here demonstrate the need for complementarity with other methods to diagnose canine periodontal disease and reinforce the need for additional studies with more markers of systemic inflammatory response.

Evaluation of Blood C Reactive Protein (CRP) and Neutrophil-to-Lymphocyte Ratio (NLR) Utility in Canine Epilepsy

BACKGROUND

The role of neuroinflammation in epileptogenesis has been previously explored, and several biomarkers have been identified as being relevant in assessing the intensity of the inflammatory process. In human medicine, an increased C reactive protein (CRP) blood concentration and/or neutrophil-to-lymphocyte ratio (NLR) is considered a constant finding of epileptic activity. In veterinary medicine, only a few studies have been published regarding both of these topics.

HYPOTHESIS/OBJECTIVES

Our aim was to assess the C reactive protein blood concentration and the neutrophil-to-lymphocyte ratio in epileptic dogs, regardless of etiology.

METHOD

This retrospective study was based on changes in routine blood parameters in 59 dogs with epileptic activity.

RESULTS

An increased C reactive protein concentration was observed mostly in the dogs affected by structural epilepsy, and all epileptic dogs displayed abnormal neutrophil-to-lymphocyte values.

CONCLUSIONS

Based on the authors' knowledge, this is the first report regarding the NLR in epileptic dogs. Both the CRP concentration and the NLR might be considered feasible non-specific markers of the neuroinflamation involved in epileptogenesis and might be used in the diagnosis of and therapeutic approach to cluster seizures in dogs with idiopathic epilepsy and in patients with structural epilepsy. Dogs diagnosed with IEis and high CRP concentrations and NLRs may be subject to non-documented cluster seizures. Both CRP and the NLR have limited diagnostic value in dogs with reactive seizures.

Neutrophil-to-lymphocyte ratio and red blood cell distribution width to platelet ratio and their relationships with inflammatory and antioxidant status in dogs with different stages of heart failure due to myxomatous mitral valve disease

We aimed to evaluate the red blood cell distribution width-to-platelet ratio (RDW/PLT) with other complete blood cell count (CBC) indices and their correlations with serum proinflammatory cytokines, acute phase proteins (APPs), and antioxidant biomarkers in dogs at different stages of heart failure (HF). A total of 29 dogs were divided into four groups according to the ACVIM Consensus Statement: stage-A (healthy/controls, n = 8), stage-B2 (n = 6), stage-C (n = 10), and stage-D (n = 5). Seventeen CBC indices were calculated and correlated with the measurements of inflammatory, APPs, and antioxidant biomarkers, as well as selected echocardiographic variables in all dogs. At stage-C, CBC indices were evaluated 14 days after the treatment. Statistically significant changes were observed only for RDW/PLT and neutrophil-to-lymphocyte ratio (NLR) between groups. NLR increased, but RDW/PLT deceased in dogs with HF, compared to controls (P < 0.05). There were no statistically differences between pre- and post-treatment CBC indices. There were significantly positive and negative correlations between the CBC indices, serum parameters and selected echocardiographic variables in dogs with HF(P < 0.05). ROC analysis showed the best sensitivity (57% and 68%) and specificity (100% and 57%) for NLR > 5.8 and RDW/PLT ≤ 0.057 for predicting the severity of HF, respectively. Results showed that NLR and RDW/PLT may have potential for monitoring severity of the disease and the effect of treatment in dogs with HF. Imbalances between indices of circulating blood cells can contribute to immunoinflammatory and antioxidant responses in pathogenesis of canine HF, which may provide us alternative targets to develop new diagnostic and therapeutic strategies in veterinary medicine.

Clinical importance of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and systemic immune-inflammation index in dogs with leishmaniasis

Leishmaniasis is a zoonotic disease caused by Leishmania spp., impacts multiple systems and organs. While hematological and biochemical profiles aren't definitive for diagnosis, recent studies have identified the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII) as predictors of morbidity and mortality in critically ill human and dog patients. This study examined 100 dogs diagnosed with leishmaniasis, categorized by the International Renal Interest Society (IRIS) stages 1-4. Additionally, the dogs were divided based on whether they survived less or more than one year (L1Y and G1Y). Control group consisted of 43 dogs. The NLR increased as the disease progressed (IRIS 1-4), presenting statistically significant differences (P<0.05) when compared to the control group (2,37±2,08) IRIS 3 and 4 (4,59±13,39 and 6,99±12,86, respectively), and G1Y and L1Y (3,60±4,02 and 4,87±5,82, respectively). Significant changes in SII were only evident in short-term survivors (L1Y 951,93±1402) and advanced renal disease cases (IRIS 4 stage 1073,68±1901,09). Conversely, PLR remained largely unchanged. In conclusion, these results suggest that the neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII) may serve as potential markers for assessing disease progression and prognosis in dogs diagnosed with leishmaniasis.

Association of the neutrophil-lymphocyte ratio with outcome in sick hospitalized neonatal foals

BACKGROUND

The neutrophil-lymphocyte ratio (NLR) in human medicine is an objective biomarker that reflects prognosis. The NLR as an independent biomarker to help predict nonsurvival in hospitalized neonatal foals has not been thoroughly interrogated.

OBJECTIVES/HYPOTHESIS

Retrospectively evaluate if the NLR at admission is associated with nonsurvival in sick hospitalized foals <4 days old. We hypothesized that a lower NLR will be associated with nonsurvival.

ANIMALS

One thousand one hundred ninety-six client-owned foals <4 days old of any breed and sex: 993 hospitalized foals and 203 healthy foals.

METHODS

Retrospective multicenter study. Medical records of foals presenting to 3 equine referral hospitals were reviewed. Foals were included if they had complete CBCs, sepsis scores, and outcome data. The NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. Data were analyzed by nonparametric methods and univariate analysis.

RESULTS

Of the 993 sick hospitalized foals, 686 were sick nonseptic and 307 were septic. The median NLR was lower in sick hospitalized foals (median [95% confidence interval], 3.55 [0.5-13.9]) compared with healthy foals (6.61 [3.06-18.1]). Septic foals had the lowest NLR (2.00 [0.20-9.71]). The NLR was lower in nonsurviving (1.97 [1.67-2.45]) compared with surviving foals (4.10 [3.76-4.33]). Nonsurviving septic foals had the lowest NLR (1.47 [1.70-3.01]). Foals with a NLR of <3.06 or <1.6 at admission had odds ratio of 3.21 (2.24-4.29) and 4.03 (2.86-5.67) for nonsurvival, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

A NLR < 3.06 at admission in sick hospitalized foals is readily available and clinically useful variable to provide prognostic information.

Concurrent hepatopathy in dogs with gallbladder mucocele: Prevalence, predictors, and impact on long-term outcome

BACKGROUND

Information is limited regarding the prevalence and importance of hepatic histologic abnormalities in dogs with gallbladder mucocele (GBM).

OBJECTIVES

To (a) report prevalence of hepatic histologic abnormalities in dogs with GBM (b) evaluate for association between hepatic abnormalities and outcome in dogs with GBM (c) evaluate whether neutrophil-to-lymphocyte ratio (NLR) differs in dogs with GBM with and without specific hepatic lesions.

ANIMALS

Fifty-two dogs with grossly and histologically confirmed GBM.

METHODS

Multicenter, retrospective study of dogs with GBM undergoing cholecystectomy with concurrent liver biopsy. Archived histological sections of gallbladder and liver evaluated by investigators blinded to data. Proportions of dogs with each histologic abnormality alive vs deceased at 1, 3, and 12 months post-cholecystectomy compared. Mann-Whitney U performed to determine if NLR differed in dogs with or without selected lesions.

RESULTS

51/52 (98%, 95% CI [89%, 99%]) dogs with GBM had at least 1 hepatic histologic abnormality. Hepatic fibrosis (37/51; 73%, 95% CI [59%, 83%]), biliary hyperplasia (29/52; 56%, 95% CI [42%, 68%]), and portal inflammation (25/52; 48%, 95% CI [35%, 61%]) were most common. The proportion of dogs alive vs dead differed based on the fibrosis score at 1, 3, and 12 (P ≤ .04) months post-cholecystectomy. Dogs with hepatic necrosis (P = .006) and cholangitis/cholangiohepatitis (P = .02) had higher NLRs compared to dogs without these lesions.

CONCLUSIONS AND CLINICAL IMPORTANCE

Histologic abnormalities of the liver are common in dogs with GBM. A higher portal fibrosis score might be associated with shortened long-term survival after cholecystectomy for dogs with GBM. An increase in NLR might predict hepatic necrosis and cholangitis/cholangiohepatitis in dogs with GBM.

Retrospective evaluation of hematological ratios in canine parvovirosis: 401 cases

BACKGROUND

The utility of neutrophil-to-lymphocyte ratio (NLR), platelet to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) as prognostic indicators has not been investigated in canine parvovirosis (CPV).

HYPOTHESIS

To evaluate whether these hematological ratios obtained at hospital admission in CPV are associated with outcome or duration of hospitalization.

ANIMALS

Four hundred one client-owned dogs presented with CPV. Methods-Retrospective multicenter cohort study. Medical records were reviewed to identify dogs with CPV. Data regarding signalment, complete blood count at admission, duration of hospitalization and outcome were collected.

RESULTS

Of the 401 dogs included in the study, 336 (83.8%) survived to discharge. The median (25th and 75th percentiles) PLR in nonsurvivors (336.56 [159.84-635.77]) was significantly higher than in survivors (217.65 [117.67-389.65]) (P = .003). The area under the receiver-operating characteristic curve for nonsurvival was 0.615 (95% CI [0.593-0.691], P = .003). A cut off of 700 showed a 21.5% sensitivity and 90% specificity for nonsurvival. No association was observed between hospitalization duration and either hematological ratios or total WBC counts. The median (25th and 75th percentiles) lymphocyte count was below reference interval in all dogs and was significantly lower in the dogs which died (0.82 × 109 /L [0.5-1.87]) than in survivors (1.27 × 109 /L [0.73-2.22]) (P = .005). The median (25th and 75th percentiles) monocyte count however was lower in survivors (0.38 × 109 /L [0.29-1.59]), than in nonsurvivors (0.73 × 109 /L [0.1-2]) (P = .002).

CONCLUSIONS

Evaluation of PLR at hospital admission might be a useful marker of disease severity and could have prognostic value in dogs with CPV.

New insights into the treatment of meningoencephalomyelitis of unknown origin since 2009: A review of 671 cases

“Meningoencephalomyelitis of unknown origin” (MUO)—a collective term for a group of clinically-indistinguishable (but pathologically distinct) autoimmune diseases of the CNS—has become increasingly commonly recognized throughout the world. In the 1960s−1980s the focus was primarily on the pathological description of these conditions and, largely anecdotally, their response to glucocorticoids. The subsequent availability of magnetic resonance imaging for companion animals led to a focus on imaging characteristics and response of MUO to various immunosuppressive medications. Previous reviews have not found clear evidence of superiority of any specific treatment regimen. Here, we review outcomes in a further 671 dogs treated with various combinations of glucocorticoids and immunosuppressive drugs and reported since 2009, aiming to determine whether recommendations can be drawn from the material published during more recent decades. We observe that: (i) there is more complete information on outcome of MUO-affected dogs solely receiving glucocorticoids and these reports provide evidence to undermine the dogma that MUO inevitably requires treatment with glucocorticoids plus an immunosuppressive drug; (ii) there is far more information on the pharmacokinetics of cytarabine delivered by a variety of routes, revealing that previous dosing and duration of administration in dogs with MUO may not have been optimal; and, (iii) there is a large number of cases that could be available for entry into multi-institutional randomized controlled trials. Finally, we suggest new research avenues that might aid future clinical trials in MUO through improved understanding of etiological triggers and individual patterns of immune response, such as the impact of the gut microbiome, the potential of CSF flow cytometry, and the establishment of robust clinical scores for evaluation of treatment success.