Interleukin-8 in urine: a new diagnostic parameter for intra-amniotic infection after premature rupture of the membranes

Urinary progesterone-induced blocking factor concentration is related to pregnancy outcome

Peripheral lymphocytes from healthy pregnant women secrete a mediator protein named the progesterone-induced blocking factor (PIBF) that exerts an immunomodulatory function and contributes to the maintenance of pregnancy in mice. The gene coding for PIBF mRNA has been cloned and sequenced, and now the recombinant human protein is available. The aim of this study was to develop an ELISA test for determining PIBF concentrations in biological samples of pregnant women. We determined urinary PIBF concentrations of 86 healthy nonpregnant individuals and from almost 500 pregnant women by ELISA. During normal pregnancy, the concentration of PIBF continuously increased until the 37th gestational week and was followed by a sharp decrease after the 41st week of gestation. In pathological pregnancies, urinary PIBF levels failed to increase. The onset of labor was predictable on the basis of this test, whether it was term or preterm delivery. In urine of patients with preeclampsia, PIBF concentrations were significantly lower than in normal pregnancy and showed a correlation with the number of symptoms presented. These data, in line with previous in vivo findings, suggest that PIBF production is a characteristic feature of normal pregnancy, and determination of PIBF concentration in urine might be of use for the diagnosis of threatened premature pregnancy termination.

Urinalysis for interleukin-8 in the non-invasive diagnosis of acute and chronic inflammatory diseases

BACKGROUND AND AIMS

Given its role in mediating inflammation, the use of urinary interleukin-8 (IL-8) was assessed in the non-invasive diagnosis of acute and chronic inflammatory diseases.

METHODS

IL-8 was measured by an enzyme linked immunosorbent assay in random urine samples (1 ml each) carrying code numbers and taken from 208 patients: 177 adults and 31 children presenting with a range of active or inactive inflammatory conditions.

RESULTS

In the appropriate controls and in patients with inactive inflammation, the median urinary IL-8 levels ranged from 7-12 pg/ml, compared with 104 pg/ml in active ulcerative colitis (p = 0.002), 54 in active Crohn's disease (p = 0.025), 93 in active rheumatoid arthritis (p = 0.001), 107 in acute cholecystitis (p<0.0001), 127 in acute appendicitis (p = 0.0001), and 548 pg/ml in urinary tract infection (p<0.0001). Children with non-viral inflammation/infection also had higher IL-8 values (median, 199 pg/ml; p = 0.0001) than those with viral infection (median, 7 pg/ml) or non-specific conditions (median, 10 pg/ml). In the study group as a whole urinary IL-8 values correlated positively with peripheral blood white cell count (r = 0.32; p < 0.001), erythrocyte sedimentation rate (r = 0.41; p<0.001), and C-reactive protein (r = 0.33; p<0.001).

CONCLUSION

Taking the appropriate clinical situation into account, urinary IL-8 measurement helps in the non-invasive assessment of active inflammation in at least a number of common acute and chronic conditions.

Cytokines and other important inflammatory mediators in gestation and bacterial intraamniotic infections

Intraamniotic infections caused by viruses, bacteria or mycoplasmas are frequently followed by damage of fetus or increased perinatal morbidity and mortality. Cytokines are key substances regulating a number of biological processes including reproductive and inflammatory processes. An association between intraamniotic infections, rising concentrations of inflammatory cytokines in amniotic fluid and preterm labor is suggested. A great effort is made to find reliable markers typical for intraamniotic infections with high predictive value that make possible prompt identification of patients with intraamniotic infection. This review concerns inflammatory mediators, especially IL-1, IL-6, IL-8, TNF-alpha, and other important biologically active substances as prostaglandins and NO metabolites and their roles in intraamniotic infections. Finally, we discuss their relevance for diagnosis of intraamniotic infections.

Determination of Total Interleukin-8 in Whole Blood after Cell Lysis

Background: It has been shown that a high percentage of interleukin-8 (IL-8) in blood is cell associated. Recently, a simple method for determination of cell-associated IL-8 in whole blood after cell lysis has been described. The purpose of this study was to evaluate this method, to examine the influence of preanalytic sample handling, and to establish the concentration range of total IL-8 and its relation to age and sex in healthy subjects.

Methods: Total IL-8 content of whole blood was determined after lysing blood cells with Milenia® cell lysis solution. IL-8 in the resulting blood lysate was measured with the IMMULITE® IL-8 immunoassay.

Results: When freshly drawn blood was stored up to 48 h on ice, no significant changes in total IL-8 were measured in the subsequently prepared lysate, whereas with storage at room temperature, total IL-8 increased after 3 h from 94 ± 13 ng/L to 114 ± 16 ng/L (n = 10). In lysate stored for 48 h at 4 °C, marginal changes of the IL-8 concentration were noted, with storage at room temperature, only 76% ± 5% (n = 12) of initial concentration was recovered. From lysate frozen at −20 and −80 °C, respectively, 84% ± 4% and 93% ± 2% of initial IL-8 was recovered after 70 days (n = 10). IL-8 was measured with comparable precision in plasma (CV, 3.2–4.2%) and blood lysate (CV, 3.7–4.1%). When plasma was diluted with cell lysis solution, a slightly overestimated recovery (125% ± 3%) was observed; for lysate specimens with a cell lysis solution content ≥75%, the recovery after dilution was 98% ± 2%. In lysate prepared from 12 blood samples with exogenous IL-8 added, IL-8 recovery was 104% ± 2% (recovery from plasma &lt;35%). The median total IL-8 in blood lysates from 103 healthy subjects (22–61 years) was 83 ng/L of blood (2.5–97.5 percentile range, 49–202 ng/L of blood). In females but not in males, total IL-8 increased significantly with advancing age (P &lt;0.002). We found grossly increased total IL-8 in six pregnant women with amniotic infection syndrome.

Conclusions: The evaluated method allows the assessment of total IL-8 in blood with good performance when appropriate conditions of sample pretreatment are considered. The values in healthy volunteers all were above the detection limit of the IL-8 assay; therefore, slight changes of total IL-8 could be noted. Thus, the present method is a suitable tool to study the diagnostic relevance of total IL-8 in blood.

Urinary markers of disease activity in multiple sclerosis

Numerous markers of disease activity, representing different aspects of the inflammatory cascade and pathogenic process in multiple sclerosis, can be detected in the urine. Urinary monitoring provides distinct advantages over blood and cerebrospinal fluid: it is easier to collect, allows frequent sampling and acts as a natural integrator by capturing the excretion of a substance over a prolonged period of time. We will discuss the principles, advantages, and pitfalls of urinary monitoring in relationship to multiple sclerosis.