Clinical utility of a rapid test for uristatin

Urinary trypsin inhibitor levels are reduced in cerebrospinal fluid of multiple sclerosis and neuromyelitis optica patients during relapse

BACKGROUND

Neutrophil-mediated inflammation plays an important role in the pathogenesis of multiple sclerosis (MS) and neuromyelitis optica (NMO). Concentrations of urinary trypsin inhibitor (UTI) have attracted attention as a useful index of the status of inflammatory response. Evidence suggests serum UTI levels are increased in some inflammatory diseases, but little attention has been paid to cerebrospinal fluid (CSF) levels of UTI.

OBJECTIVE

To measure CSF concentration of UTI and determine its relationship with disease activity in MS and NMO.

METHODS

CSF UTI was measured by an enzyme-linked immunosorbent assay in 18 MS patients, 28 NMO patients and eight controls.

RESULTS

CSF UTI concentrations in MS and NMO groups were both significantly lower than those in controls. Expanded disability status scale scores of MS and NMO revealed a trend of increased disease disability with decreased CSF UTI level. The CSF UTI concentrations were not significantly associated with CSF white blood cell counts, total protein, glucose and chlorine concentrations in MS and NMO subgroups.

CONCLUSIONS

Our results indicate a reduced UTI level in CSF of MS and NMO patients. The levels were associated with the severity of the two demyelinating diseases during relapse.

Serum CRP and urinary trypsin inhibitor implicate postoperative cognitive dysfunction especially in elderly patients

PURPOSE

Postoperative cognitive dysfunction (POCD) characterized as the decline of memory and executive function after major surgery is not well illustrated. The aim of this study is to discover whether inflammatory cytokines and urinary trypsin inhibitor (uTi) contribute to the development of POCD.

METHOD

Sixty-three patients undergoing lumber discectomy and 47 age-matched control volunteers were involved in this study. The level of C-reaction protein (CRP) and uTi/urine creatinine (Ucr) was measured by immunoturbidimetry and enzyme-inhibition assay, respectively. Meanwhile, ELISA was involved to detect the level of IL-6, IL-10, MMP-9 in serum. Montreal Cognitive Assessment (MoCA) test was used to determine the cognitive decline of the patients and age-matched controls.

RESULT

In POCD group, the level of IL-6, IL-10, CRP, MMP-9 in serum and uTi /Ucr in urine was significantly higher than that in the group without POCD. The POCD was more frequently observed in elderly group than in the middle-aged group (43.75% versus 19.35%, p = 0.038). After logistic regression analysis adjusted by the age, only serum CRP at 72 h postoperation and urinary uTi /Ucr at 24 h postoperation were the independent risk factors of POCD.

CONCLUSION

Age-related increasing proinflammatory postoperation may result in higher occurrence of POCD in the elderly. Additionally, patients with extremely high concentrations of CRP in serum at 72 h postoperation and uTi /Ucr in urine at 24 h postoperation are more likely to experience POCD, especially in the elderly.

Effect of ulinastatin on the expression of iNOS, MMP-2, and MMP-3 in degenerated nucleus pulposus cells of rabbits

We examined the effects of ulinastatin on the expression of inducible nitric oxide synthase (iNOS), matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-3 (MMP-3) in degenerated nucleus pulposus (NP) cells of rabbits induced by interleukin (IL)-1β in vitro. An in vitro NP cell culture model was set up with enzyme digestion. NP cells from adult white rabbits were divided into six groups: the normal control group, the ulinastatin control group (320 U/mL ulinastatin), the induced group (10 ng/mL IL-1β), and three inhibition groups (IL-1β followed by 160, 320, or 640 U/mL ulinastatin). After a 2-day culture, the NP cells were collected for immunohistochemical staining for MMP-2 and MMP-3 and spectrophotometric analysis of the amount of iNOS. Immunohistochemical staining showed that the expression of MMP-2 and MMP-3 proteins in NP cells decreased in the inhibition groups compared with the induced group, which was in inverse proportion to the ulinastatin concentration. Spectrophotometric results showed that, compared with the induced group, the iNOS content in each inhibition group decreased, most significantly in the 320 U/mL group. Ulinastatin effectively inhibited the increased expression of MMP-2, MMP-3, and iNOS in degenerated NP cells induced by IL-1β in vitro. It suggests that ulinastatin may potentially be useful for clinical therapy of intervertebral disc degeneration.

Immunological evaluation of urinary trypsin inhibitors in blood and urine: role of N- & O-linked glycoproteins

Urinary trypsin inhibitors (uTi) suppress serine proteases during inflammation. After liberation from proinhibitors (P-alpha-I and I-alpha-I) by the white blood cell (WBC) response, uTi readily pass through the kidneys into urine. A key uTi, bikunin, is attached to O-linked and N-linked glycoconjugates. Recently, uTi inhibitors, called uristatins, were found to lack the O-linked glycoconjugates. Monoclonal antibodies were produced using purified uristatin and screened for binding differences to uristatin, bikunin, P-alpha-I, and I-alpha-I. Antibody-binding patterns were characterized using immunoaffinity binding onto protein-chip surfaces and analysis by Surface Enhanced Laser Desorption/Ionization mass spectrometry (SELDI), using specimens from patients and from purified uTi standards. Antibodies were developed and used in an enzyme-linked immunosorbent assay (ELISA) method for uTi measurement in urine and plasma specimens. ELISA was performed on specimens from normal, presumed healthy, controls and from patients who had been screened for inflammation using a high sensitivity C-reactive protein (CRP) test and a complete blood count (CBC). Polyclonal antibody against uTi showed cross-reactivity with the Tamm-Horsfall protein (THP) and with proinhibitors. Screening of anti-uTi monoclonal antibodies (Mab) revealed antibodies that did not cross-react with either of the above, thus providing a tool to measure both uristatin and bikunin in urine with Mab 3G5 and in plasma with Mab 5D11. The monoclonal antibody 5D11 cross-reacts with specific N-linked glycoconjugates of uristatin present in plasma. In ca 96% of healthy adults, uTi were present at <12 mg/l in urine and <4 mg/l in plasma. We also found that patients with an inflammation and a CRP of >2.0 mg/l had higher urinary concentrations of uTi than the control population in every subject. Free uristatin and bikunin pass readily into urine and are primarily bound to heavy chains that constitute the proinhibitor form in plasma.

Bikunin (Urinary Trypsin Inhibitor): Structure, Biological Relevance, And Measurement

Inflammatory processes, such as phagocytosis, coagulation, and vascular dilation, promote the release of serine proteases by neutrophils, macrophages, mast cells, lymphocytes, and the epithelial or endothelial cells. These proteases further facilitate the release of inflammatory cytokines and growth factors as well as take part in signal-cell proliferation through protease-activated receptors (PARs). Controlling the action of this cascade is necessary to prevent further damage to the normal tissues. One of the main anti-inflammatory response mediators is bikunin (Bik) that is responsible for inhibiting the activity of many serine proteases such as trypsin, thrombin, chymotrypsin, kallikrein, plasmin, elastase, cathepsin, Factors IXa, Xa, XIa, and XlIa. During the acute-phase response, Bik is released into plasma from proinhibitors primarily due to increased elastase activity. Bik is a glycoprotein, also referred to as urinary trypsin inhibitor, which in plasma inhibits the trypsin family of serine proteases by binding to either of the two Kunitz-binding domains. Bik also accumulates in urine. In conditions such as infection, cancer, tissue injury during surgery, kidney disease, vascular disease, coagulation, and diabetes, the concentrations of Bik in plasma and urine are increased. Several trypsin inhibitory assays for urine and immunoassays for both blood and urine have been described for measuring Bik. In addition to presenting the synthesis, structure, and pathophysiology of Bik, we will summarize various diagnostic approaches for measuring Bik. Analysis of Bik may provide a rapid approach in assessing various conditions involving the inflammatory processes.

Pathophysiology and diagnostic value of urinary trypsin inhibitors

Inflammation is an important indicator of tissue injury. In the acute form, there is usually accumulation of fluids and plasma components in the affected tissues. Platelet activation and the appearance in blood of abnormally increased numbers of polymorphonucleocytes, lymphocytes, plasma cells and macrophages usually occur. Infectious disorders such as sepsis, meningitis, respiratory infection, urinary tract infection, viral infection, and bacterial infection usually induce an inflammatory response. Chronic inflammation is often associated with diabetes mellitus, acute myocardial infarction, coronary artery disease, kidney diseases, and certain auto-immune disorders, such as rheumatoid arthritis, organ failures and other disorders with an inflammatory component or etiology. The disorder may occur before inflammation is apparent. Markers of inflammation such as C-reactive protein (CRP) and urinary trypsin inhibitors have changed our appraisal of acute events such as myocardial infarction; the infarct may be a response to acute infection and (or) inflammation. We describe here the pathophysiology of an anti-inflammatory agent termed urinary trypsin inhibitor (uTi). It is an important anti-inflammatory substance that is present in urine, blood and all organs. We also describe the anti-inflammatory agent bikunin, a selective inhibitor of serine proteases. The latter are important in modulating inflammatory events and even shutting them down.

Sensitive noninvasive marker for the diagnosis of probable bacterial or viral infection

Urinary trypsin inhibitor (uTi) is a product of elastase-mediated degradation of interleukin-alpha-inhibitor (I-alpha-I). Its activity increases in the urine of patients with a malignancy, inflammation, or infection, or in late pregnancy. The objective of this study was to compare the sensitivity of uTi in urine with that of serum quantitative C-reactive protein (CRP) for diagnosing infection, as indicated by white cell response and clinical assessment. Ninety controls and 171 patients with various systemic infections were enrolled. We measured uTi enzymatically on a Cobas Fara (Roche Diagnostics). Patients were separated into bacterial, probable bacterial, viral, or probable viral groups based on the results of a complete blood count with differential (CBC), urinalysis (UA), and clinical assessment. In the bacterial (n=70) and control (n=90) groups, the uTi values (mean+/-SE) were 25.3+/-3.1 mg/L and 2.8+/-0.8 mg/L, respectively. uTi (at 2.7 mg/L) had a diagnostic sensitivity of 91% and specificity of 82% (AUC=0.889), whereas CRP (at a cutoff of 10 mg/L) had a sensitivity and specificity of 82% and 96%, respectively (AUC=0.921). As a marker of infection (positive in both bacterial and viral groups), uTi had a sensitivity of 91% (AUC=0.884) vs. 89% (AUC=0.828) for CRP. Our data indicate that uTi has sufficient clinical sensitivity for screening systemic infections, and may have diagnostic value as a noninvasive test.

Neutrophil-mediated inflammation in respiratory syncytial viral bronchiolitis

BACKGROUND

The involvement of neutrophil-mediated inflammation may play an important role in the pathogenesis of acute respiratory syncytial virus bronchiolitis. However, no measurable marker is sensitive enough to assess neutrophil-mediated inflammation in the airways. Released neutrophil elastase (NE) in intraluminal airways has been reported to induce pulmonary inflammation. The aim of this study was to determine whether the amount of urinary trypsin inhibitor (UTI) in serum, a degenerate induced by NE, reflects the degree of airway inflammation in children with respiratory syncytial viral (RSV) bronchiolitis and whether the severity of inflammation is evaluated. The pre-alpha-/inter-alpha-trypsin inhibitor is assumed to be precursors of the UTI. When NE degrades these inhibitors, UTI is liberated.

METHODS

Serum UTI concentrations in infants admitted with RSV bronchiolitis, other viral infections, bacterial pneumonia and control subjects were measured by means of one-step sandwich-type enzyme immunoassay.

RESULTS

Serum UTI concentrations in 25 patients on admission were significantly higher than the 15 infantile control values (mean +/- SEM, 22.126 +/- 2.317 and 6.701 +/- 0.719 U/mL, respectively; P < 0.0001). The elevated levels returned to baseline values with improvement in the respiratory symptoms. Higher levels of serum UTI with RSV infection were consistently associated with clinical symptoms and artificial ventilation. Serum NE concentrations of patients were elevated in some patients but not significantly different from controls in the patients who showed only upper respiratory symptoms with RSV infections.

CONCLUSION

The findings strongly suggested that neutrophil-mediated events are involved in the pathogenesis of RSV bronchiolitis, and the monitoring of UTI concentrations might be useful for evaluating the neutrophil-mediated airway inflammation.

Protective effects of tumor necrosis factor α antibody and ulinastatin on liver ischemic reperfusion in rats

AIM: To study the protective effects of tumor necrosis factor α (TNF α ) antibody and ulinastatin on liver ischemic reperfusion in rats.

METHODS: One hundred and twenty male SD rats were randomly divided into four groups: Normal control group, ischemic group, TNFα antibody group and TNFα antibody + ulinastatin group. The animals were killed at 0, 3, 6, 9, 12 h after ischemia for 60 min and followed by reperfusion. Serum alanine aminotransferase (ALT), malondialdehyde (MDA) and liver histopathology were observed.

RESULTS: After ischemic reperfusion, the serum ALT and MDA were remarkably increased, and the hepatic congestion was obvious. Treatment of TNFα antibody and ulinastatin could significantly decrease serum ALT and MDA levels, and relieve hepatic congestion.

CONCLUSION: Ulinastatin and TNFα antibody can suppress the inflammatory reaction induced by hepatic ischemic reperfusion, and have protective effects on rat hepatic ischemic reperfusion injury.

The uristatin dipstick is useful in distinguishing upper respiratory from urinary tract infections

BACKGROUND

We determined the diagnostic value of the trypsin inhibitor, uristatin, that is commonly found in urine and plasma in patients with infections or inflammations of any kind.

METHODS

We collected urine specimens from patients with infections of the urinary or upper respiratory tract and from healthy controls. We also collected blood from patients with a likely upper respiratory tract infection and healthy controls. A bacterial count of >10(5) organisms/ml in urine was considered to represent infection rather than contamination.

RESULTS

The uristatin dipstick test in urine showed acceptable negative predictive values (NPV of up to 93%) for patients without infection or inflammation. Here, the dipsticks could eliminate some urine cultures. For those with infection or inflammation, the positive predictive values (PPV) of the dipsticks were lower (up to 57%). Including the leukocyte esterase and nitrite values increased the PPV of the dipsticks for those with disease.

CONCLUSIONS

The uristatin strip was more accurate than the leukocyte and nitrite dipsticks for predicting upper respiratory infections (URI) and C-reactive protein for those with infection or inflammation. The uristatin dipstick was able to detect both the bikunin and uristatin inhibitors.

Near-patient testing for infection using urinalysis and immuno-chromatography strips

Urinary tract infections require costly confirmatory tests such as a urine culture to establish the diagnosis. Elimination of the culture step would save resources; diagnosis and treatment could begin in hours rather than days. We tested a new dip-and-read strip that uses immuno-chromatography (IC) to detect infectious agents in urine. We used a goat-derived polyclonal antibody with reactivity to the cell-wall proteins of

Fever without apparent source on clinical examination

This section focuses on issues in infectious disease that are commonly encountered in pediatric office practices. Dr. McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children and the evaluation of children with prolonged fevers of unknown origin. Drs. Klig and Chen (pp 121-126) review recent literature about lower respiratory infection in children. This section focuses on febrile children in whom a source of fever is not readily apparent on clinical examination. This issue is discussed in several contexts: recent developments concerning the epidemiology, pathophysiology, diagnostic approach, and therapy of febrile illnesses; children from 3 to 36 months of age with fever; infants younger than 90 days of age with fever; and children of any age with prolonged fever, usually lasting more than 7 to 10 days, for whom a diagnosis has not been established.