The effect of physiological parameters on serum lactate dehydrogenase isoenzymes in lambs

The effect of age, sex and growth rate on total serum lactate dehydrogenase (LDH) and its isoenzymes was assessed in Suffolk X Halfbred lambs from 1.5 days to 10 weeks old. The total LDH activity was higher at 1.5 days than in older lambs and the percentage of LDH₁ tended to increase while LDH₄ and LDH₅ decreased with age from 2 weeks, indicating that the isoenzyme distribution was changing towards the adult pattern. In female lambs, the percentage of LDH₁ was higher than in male lambs at 1.5 days, but little importance was attached to this finding since the difference was not significant at 10 weeks. No clear relationships existed between the level of total LDH or its isoenzymes and daily liveweight gain.The age-related changes were considered to be of greater significance than those related to sex and growth rate when interpreting serum LDH levels in lambs.     

Cutaneous T-cell lymphoma in a heifer with increased serum lactate dehydrogenase activity

A 1-year-old heifer from an enzootic bovine leukemia virus (BLV)-free breeding herd was examined for numerous cutaneous plaques on the neck, shoulder, back, perineum, and tail. Impression smears of the skin lesions contained a large population of neoplastic lymphoblastic cells. Hematologic findings included mild anemia, neutrophilia, and lymphocytosis. The serum activity of lactate dehydrogenase (LDH) was moderately increased at admission (4712 U/L), and remained increased despite normal to minimally increased activities of liver- and muscle-specific enzymes. The heifer was serologically negative for BLV. Because of declining condition and poor prognosis, the heifer was euthanized on day 37 after presentation. At necropsy and on histologic examination, epitheliotropic and folliculotropic cutaneous lymphoma, with generalized involvement of lymph nodes and spleen and infiltration of liver and kidney, was diagnosed. Immunophenotyping results (CD79-, CD3+) were consistent with a lymphoma of T-cell origin. We concluded that cutaneous T-cell lymphoma had spread to the other internal organs, and that the neoplasm likely contributed to increased serum LDH activity.     

Serum lactate dehydrogenase activity in canine malignancies

Lactate dehydrogenase (LDH) is commonly used in human cancer patients for prognostic purposes. Aim of this study was to determine the magnitude of serum LDH elevation in dogs with cancer compared with healthy dogs and dogs with non-neoplastic disease, and to verify whether it may support the diagnosis of specific malignancies. About 128 healthy dogs, 211 diseased dogs and 188 cancer dogs were enrolled. Dogs with cancer had significantly higher LDH than diseased ( P < 0.001) and healthy dogs ( P < 0.001), but large overlap was found. Dogs with lymphoma showed significantly higher LDH compared with dogs with carcinoma ( P < 0.001) or mast cell tumour (MCT; P < 0.05) but not compared with other malignancies. When considering lymphoma and MCT, LDH levels were not different between early and advanced clinical stages. Measuring LDH levels may not be useful as a screening tool for cancer detection. More studies are needed to define its role in specific tumours.     

Reference intervals for the activity of lactate dehydrogenase and its isoenzymes in the serum and cerebrospinal fluid of healthy canines

Background

Lactate dehydrogenase (LD) exists as 5 isoenzymes (LD‐1 through LD‐5) that are expressed throughout the body and can be detected in both serum and cerebrospinal fluid (CSF). LD and its isoenzymes have been relatively unstudied in veterinary medicine, although studies in human medicine have demonstrated that changes in total LD activity and atypical isoenzyme patterns can indicate disease processes, including neurologic abnormalities.

Objectives

The purpose of this study was to establish RIs for LD and its isoenzymes in the serum and CSF of clinically healthy dogs. By establishing a definitive RI for this enzyme in healthy canines, further study of the clinical and diagnostic usefulness of LD can be undertaken.

Methods

Serum and atlantoaxial CSF were collected from clinically healthy dogs. Total LD activity was measured spectrophotometrically immediately after collection. Isoenzyme distributions were also determined within 8 hours of collection using the QuickGel LD Isoenzyme technique and a densitometric scanner.

Results

The median serum total LD in healthy canines was 69.0 U/L (n = 41; range: 21.0‐217.0 U/L), while the median CSF total LD was 10.0 U/L (n = 40; range: 6.0‐19.3 U/L). LD‐5 is the predominant isoenzyme in canine serum (n = 40), contributing over half of the total enzyme activity. Conversely, in canine CSF (n = 42), LD‐1 is the predominant isoenzyme, followed by LD‐2 and LD‐3.

Conclusions

Knowledge of the distribution and concentration of LD in the serum and CSF of healthy dogs will set the foundation for future studies of canine LD as a potentially clinically useful biomarker.     

Heat stability of serum lactate dehydrogenase and its isoenzymes in young and adult cattle and sheep. Evaluation of a relative heat stability test and serum determination of alpha-hydroxybutyrate dehydrogenase in diagnostic work

The heat stability of lactate dehydrogenase (LDH) has been investigated in serum from young and adult cattle and sheep. The thermoresistance of the isoenzymes was determined by electrophoresis of serum samples preincubated at different temperatures. Marked differences were found in the percentage distribution of isoenzymes in serum from the two species as well as in the heat stability. LDH in serum from sheep was inactivated at a lower temperature than that in serum from cattle, and inactivation occurred at a lower temperature in young than in adult animals. The enzyme was in both species less tolerant to elevated temperatures than what is reported for human serum. Procedures worked out for a so-called relative heat stability test of LDH in human clinical diagnosis may therefore give misleading results if they were applied uncritically to sera from these animals.The LDH isoenzyme pattern of some main organs in calves and sheep indicates that a serum heat stability test may be useful in the diagnosis of skeletal muscle injuries in sheep. In cattle the tissue isoenzyme distribution is assumed to be too uniform to give information about specific organ lesions either by serum electrophoresis or by a heating technique.In contrast to what has been reported in man, serum levels of α-hydroxybutyrate dehydrogenase (HBD) in cattle and sheep, as earlier reported in swine, are found to be far better correlated to total LDH than to the most thermostable isoenzyme, LDH₁.     

Activity of serum creatine kinase, lactate dehydrogenase and LD isoenzymes in piglets affected with congenital tremor: a case report.

The activities of serum creatine kinase (CK), lactate dehydrogenase (LD) and LD isoenzymes were studied in 14 Prestice black pied pigs from a herd affected with congenital tremor. Mean CK activity was 19.57 +/- 3.56 mu kat.l-1 for 6 adult pigs, and it was 21.03 +/- 1.33 mu kat.l-1 and 20.42 +/- 1.23 mu kat.l-1 for the affected (n = 5) and control (n = 3) piglets, respectively. No significant differences were demonstrable between the groups in CK activity. Total serum LD and LD-4 as well as LD-5 isoenzyme activities were higher in sows. Piglets affected with congenital tremor showed an increase in total LD enzyme and LD-5 isoenzyme activity. It is concluded that no relationship exists between congenital tremor and serum CK activity in piglets. At the same time, there is a positive relationship between congenital tremor and significantly (P < 0.01) elevated LD enzyme and LD-5 isoenzyme activity. The results allow us to suggest that total lactate dehydrogenase and LD-5 isoenzyme activities could be used as biological markers of congenital tremor in piglets.     

Comparison of techniques for quantifying alkaline phosphatase isoenzymes in canine serum

Three methods for quantifying the steroid-induced and liver isoenzymes of alkaline phosphatase in canine serum were compared on a group of 29 canine serum samples with increased total alkaline phosphatase activity. Levamisole inhibition, heat inactivation, and affinity electrophoresis with densitometry yielded results that correlated strongly. The relationship between levamisole inhibition and heat inactivation test values was a simple linear one, whereas the relationship between their values and those of electrophoresis was better fitted to an exponential model. The levamisole inhibition and heat inactivation tests provided essentially the same information regarding the relative proportions of steroid-induced and hepatic isoenzymes in canine serum; either test was judged practical for routine clinical application.     

High‐mobility group B1 proteins in canine lymphoma: prognostic value of initial and sequential serum levels in treatment outcome following combination chemotherapy

Elevated high‐mobility group box 1 (HMGB1) levels have been demonstrated in different human neoplasias. Information on serum HMGB1 before and during chemotherapy is lacking, as is data pertaining to its prognostic significance. The aim of this study was to characterize serum HMGB1 level in dogs with lymphoma and to assess its influence on the outcome following chemotherapy. Serum HMGB1 concentrations were measured in 16 dogs with lymphoma before treatment (W1) and on weeks 2 (W2), 6 (W6) and 12 (W12) of treatment with chemotherapy. Initial serum HMGB1 levels were significantly higher than HMGB1concentrations in control dogs and the levels in W2, W6 and W12. HMGB1‐W1 concentrations were lower in dogs achieving complete remission than that in the single dog with partial remission. The ratio W12/W6 exhibited significant influence on remission duration. In these dogs with lymphoma, serum HMGB1 was elevated in comparison with that in controls. Initial serum HMGB1 level and its modulation during treatment may possess prognostic value.     

Diagnostic and prognostic use of L‐lactate measurement in equine practice

Lactate concentrations can now be measured rapidly and inexpensively in equine hospitals or in the field with a degree of accuracy that is acceptable when compared to laboratory analysers. Arterial or venous blood samples can be used. Short‐term storage of samples for up to 4 h at room temperature does not appear to affect the result. Taking a sample in the field and returning to the practice to analyse it is therefore feasible. Lactate measurement is useful in horses with colic to aid in the diagnosis of an ischaemic lesion and to determine the probability of a successful outcome if surgery is undertaken. Lactate concentrations are also useful as an indicator of hypoxia and/or circulatory disturbances associated with intra‐, or post partum abnormalities including dystocia, prematurity, dysmaturity, neonatal encephalopathy, sepsis, systemic inflammatory response syndrome or enteritis. Measuring lactate concentrations may assist in determining the severity of these conditions and the need for intensive care. Initial lactate concentration and increases or decreases in blood lactate concentration following a period of treatment can provide useful prognostic information. Lactate may also be measured during training to monitor fitness and performance.     

Immunohistolocalization of carbonic anhydrase isoenzymes (CA-I, -II and -III ) in canine epididymis

The immunolocalization of the efferent duct and the epididymis in canine was firstly examined using an the immunohistochemical method with the canine carbonic anhydrase (CA) -I, CA-II and CA-III antisera. The efferent duct was immunonegative for all present canine CA antisera. However, some slender shaped epithelial cells in the head and body segments of the epididymal duct were intensely reacted to the CA-II antiserum. These results suggested that the CA-II might be controlled in the luminal environment in the head and body segments of the canine epididymis by the proton and bicarbonate balance for the maintenance of the spermatozoal stability and movement.     

Assessment of corticosteroid-induced alkaline phosphatase as a prognostic indicator in canine lymphoma

OBJECTIVES: To examine the incidence of elevated corticosteroid-induced alkaline phosphatase (sALP) in dogs with lymphoma and to determine if sALP is a reliable prognostic indicator in canine lymphoma. METHODS: The medical records of 62 canine lymphoma patients treated with a combination chemotherapy protocol from 1994 to 2003 at the University of Illinois Veterinary Teaching Hospital were examined. Variables assessed with respect to response rate and remission duration included age, bodyweight, sex, breed, World Health Organization stage (I to V), substage (a or b), pretreatment administration of corticosteroid, and serum levels of alkaline phosphatase, sALP and alanine aminotransferase. RESULTS: sALP was not statistically significant with respect to response rate or duration of remission, nor was preinduction glucocorticoid administration. Stage was significant with respect to achieving remission. CLINICAL SIGNIFICANCE: It was found that sALP is not a useful prognostic indicator for response rate and remission duration in dogs with lymphoma.     

Diagnostic use of serum gamma-glutamyltransferase in canine liver disease.

gamma-Glutamyltransferase (GGT) activity in canine kidney, pancreas, and liver is similar to previously reported values for other species. The low serum GGT activity in dogs (0 to 10 IU/L) may be related to relatively less liver GGT than in some other domestic animals. While determination of serum GGT in dogs may aid in the differentiation of sources of alkaline phosphatase, GGT alone appears to offer little in the diagnosis of canine liver disease. Clinical studies, as well as experimentally induced bile duct obstruction, have shown canine GGT increases to coincide with increases in alkaline phosphatase. The occasional benefit from knowledge of serum GGT in dogs would not seem to merit determination of GGT activity in routine serum chemistry panels for this species.     

Measurements of C-reactive protein in serum and lactate dehydrogenase in serum and synovial fluid of patients with osteoarthritis

Diagnosis of osteoarthritis (OA) is based upon the clinical orthopaedic examination and the radiographic assessment, both of which can be non-specific and insensitive in early joint disease. The aim of our study was to investigate if there is an increase in serum levels of C-reactive protein (CRP) in degenerative joint disease (DJD) and if CRP could be used to help diagnose OA. We also wished to investigate whether it was possible to distinguish a joint with clinically and radiographically confirmed OA from a healthy joint by comparing lactate dehydrogenase (LDH) levels within the synovial fluid and the serum. We have shown a difference in synovial LDH levels between diseased and healthy joints (P<0.0001). There was also a significant difference between LDH in arthritic synovial fluid and serum, with no correlation between the values. Despite the fact that the values of our clinical patients tended to be higher than the values of our control group (P=0.05) all measured values were within the normal limits of previous publications. From these data, we conclude that single measurements of serum CRP do not permit detection of OA in clinical patients and that serum LDH is not a reliable marker for osteoarthritis. LDH levels in the synovial fluid could be of diagnostic value for identifying osteoarthritis.     

Plasma bile acids, lactate dehydrogenase and sulphobromophthalein retention test in canine carbon tetrachloride intoxication

This paper studies the progression of various hepatic function tests (fasting and post prandial plasma bile acids, lactate dehydrogenase [LDH], hydroxybutyrate dehydrogenase [HBDH], LDH isoenzymogram, and 45 minutes sulphobromophthalein retention) in a classic model of canine hepatic injury. Sulphobromphthalein and plasma bile acid determination are excellent indicators of hepatic damage. Post prandial bile acid quantification does not improve the diagnostic capacity of this test. LDH alters only in the first 48 hours after poisoning and the study of the HBDH/LDH ratio makes it possible to differentiate the origin of plasma LDH. LDH isoenzymogram is not a practical test for routine clinical diagnosis.