Mucosal immunization with iron receptor antigens protects against urinary tract infection.

Uncomplicated infections of the urinary tract, caused by uropathogenic Escherichia coli, are among the most common diseases requiring medical intervention. A preventive vaccine to reduce the morbidity and fiscal burden these infections have upon the healthcare system would be beneficial. Here, we describe the results of a large-scale selection process that incorporates bioinformatic, genomic, transcriptomic, and proteomic screens to identify six vaccine candidates from the 5379 predicted proteins encoded by uropathogenic E. coli strain CFT073. The vaccine candidates, ChuA, Hma, Iha, IreA, IroN, and IutA, all belong to a functional class of molecules that is involved in iron acquisition, a process critical for pathogenesis in all microbes. Intranasal immunization of CBA/J mice with these outer membrane iron receptors elicited a systemic and mucosal immune response that included the production of antigen-specific IgM, IgG, and IgA antibodies. The cellular response to vaccination was characterized by the induction and secretion of IFN-gamma and IL-17. Of the six potential vaccine candidates, IreA, Hma, and IutA provided significant protection from experimental infection. In immunized animals, class-switching from IgM to IgG and production of antigen-specific IgA in the urine represent immunological correlates of protection from E. coli bladder colonization. These findings are an important first step toward the development of a subunit vaccine to prevent urinary tract infections and demonstrate how targeting an entire class of molecules that are collectively required for pathogenesis may represent a fundamental strategy to combat infections.

A pilot study to determine the safety and feasibility of oropharyngeal administration of own mother's colostrum to extremely low-birth-weight infants.

UNLABELLED: Own mother's colostrum is rich in cytokines and other immune agents that may stimulate oropharyngeal-associated lymphoid tissue if administered oropharyngeally to extremely low-birth-weight (ELBW) infants during the first days of life when enteral feeding is contraindicated. However, the safety and feasibility of the oropharyngeal route for the administration of colostrum have not been determined. PURPOSE: To determine the safety of oropharyngeal administration of own mother's colostrum to ELBW infants in first days of life. A secondary purpose was to investigate the feasibility of (1) delivering this intervention to ELBW infants in the first days of life and (2) measuring concentrations of secretory immunoglobulin A and lactoferrin in tracheal aspirate secretions and urine of these infants. SUBJECTS: Five ELBW infants (mean birth weight and gestational age = 657 g and 25.5 weeks, respectively). DESIGN: Quasi-experimental, 1 group, pretest-posttest design. METHODS: Subjects received 0.2 mL of own mother's colostrum administered oropharyngeally every 2 hours for 48 consecutive hours, beginning at 48 hours of life. Concentrations of secretory immunoglobulin A and lactoferrin were measured in tracheal aspirates and urine of each subject at baseline, at the completion of the intervention and again 2 weeks later. RESULTS: All infants completed the entire treatment protocol, each receiving 24 treatments. A total of 15 urine specimens were collected and 14 were sufficient in volume for analysis. A total of 15 tracheal aspirates were collected, but only 7 specimens (47%) were sufficient in volume for analysis. There was wide variation in concentrations of secretory immunoglobulin A and lactoferrin in urine and tracheal aspirates among the 5 infants; however, several results were outside the limits of assay detection. All infants began to suck on the endotracheal tube during the administration of colostrum drops. Oxygen saturation measures remained stable or increased slightly during each of the treatment sessions. There were no episodes of apnea, bradycardia, hypotension, or other adverse effects associated with the administration of colostrum. CONCLUSIONS: Oropharyngeal administration of own mother's colostrum is easy, inexpensive, and well-tolerated by even the smallest and sickest ELBW infants. Future research should continue to examine the optimal procedure for measuring the direct immune effects of this therapy, as well as the clinical outcomes such as infections, particularly ventilator-associated pneumonia.

Early oral colostrum administration in preterm infants.

BACKGROUND: Early administration of colostrum may provide preterm infants with immune components. Previous studies illustrating the effects of oral colostrum (OC) have been confounded by the coincidence of enteral feedings. OBJECTIVE: To quantify OC absorption, as measured by urinary sIgA and lactoferrin, in preterm infants prior to enteral feedings. MATERIALS AND METHODS: Colostrum was obtained from mothers delivering infants ≤32 weeks and ≤1500 g. sIgA and lactoferrin were measured in infant urine, and microflora in saliva and tracheal aspirates were characterized. RESULTS: Urinary sIgA and lactoferrin were significantly greater in infants receiving OC by syringe compared to swab (p < 0.002). Urinary sIgA correlated with the total number of doses in 72 h (R2 = 43%, p < 0.01). CONCLUSIONS: Administration of OC by syringe and higher cumulative dose are associated with increased absorption of sIgA and lactoferrin, and early dosing may contribute to a more diverse tracheal microbiome.

The level of urinary secretory immunoglobulin A (sIgA) of patients with IgA nephropathy is elevated and associated with pathological phenotypes.

Recent studies have demonstrated deposition of secretory immunoglobulin A (sIgA) in glomeruli of some patients with IgA nephropathy (IgAN). The aim of this study is to investigate the levels of urinary sIgA in IgAN patients with different pathological phenotypes and whether it could be used as a non-invasive biomarker for assessment of kidney injury in IgAN. Urine samples from 202 patients with IgAN were collected on the day of renal biopsy. Forty-eight fulfilled the histopathological criteria of Haas-I or II (group 1), 60 fulfilled Haas-III (group 2) and 94 patients fulfilled Haas-IV or V (group 3). Urine samples from 60 healthy sex- and age-matched volunteers with negative urinalysis were collected as normal controls. Urinary sIgA was detected by sandwich enzyme-linked immunosorbent assay and was corrected by urinary creatinine. In comparison with normal controls, the levels of urinary sIgA were significantly higher in IgAN [2.22 (0-43.82) microg/mg Cr versus 1.08 (0-16.49) microg/mg Cr, P < 0.001]. The levels of urinary sIgA were significantly higher in group 3 than that in group 2 and group 1 [3.54 (0-43.82) microg/mg Cr versus 1.63 (0-15.88) microg/mg Cr versus 0.91 (0-11.79), P < 0.001], and group 2 than group 1 (P = 0.014). The levels of urinary sIgA were associated positively with proteinuria (r = 0.443, P < 0.001), serum creatinine (r = 0.376, P < 0.001) and histopathological parameters, such as ratio of global sclerosis (r = 0.356, P < 0.001), ratio of total crescents (r = 0.339, P < 0.001) and ratios of cellular crescents (r = 0.231, P < 0.001). The levels of urinary sIgA were associated closely with histopathological phenotypes of IgAN and might be used as a non-invasive biomarker to evaluate kidney injury in IgAN.

Influence of Uro-Vaxom on sIgA level in urine in children with recurrent urinary tract infections.

We have examined the influence of Uro-Vaxom on secretory IgA (sIgA) level in urine of children with recurrent urinary tract infections. In the group of children treated with antibiotics and Uro-Vaxom, a significant increase of sIgA in the urine was found which persisted for at least 3 months. During this period no infection appeared in 92% examined children.

Mucosal immunity in the urinary tract: changes in sIgA, FSC and total IgA with age and in urinary tract infection.

The incidence of primary urinary tract infection (UTI) is greatest in the first month of life and decreases with age throughout childhood. Secretory immunoglobulin A (sIgA) is an important component of mucosal immunity. The changes in secretory IgA, IgA and free secretory component (FSC) during the first year of life were examined in relation to age, sex and in infants, feeding practice. These constituents were further compared between healthy children and those with acute and recurrent UTI. Urine was collected from 41 healthy infants (16 female: 25 male) at intervals (mean age 1.4, 9.1, 44, 91, 210 and 412 days), 139 healthy children (75 female: 64 male), 29 children with histories of recurrent UTI (25 female: 4 male) and 10 with acute UTI (8 female: 2 male). sIgA, IgA and FSC were measured by enzyme linked immunoassay. In the majority of children sIgA and IgA were undetectable at birth. SIgA and IgA rose significantly during the first year then levelled off throughout childhood. FSC was detectable from birth (geometric mean [mean of logged values]-GOM at day 1.4, 362.2 ng/ml). No sex differences were apparent for any of the three constituents at any age. Breast feeding was associated with higher levels of sIgA and IgA than bottle feeding. This was highly significant at 9.1 days when sIgA and IgA levels of breast fed compared with bottle fed infants were 64.6 ng/ml vs 21.2 and 56.2 ng/ml vs 18.7 ng/ml respectively, giving a GOM ratio of 3.04 for sIgA and 3.0 for IgA (p < 0.001 for both). No significant difference in the three parameters were demonstrable when children with recurrent UTI-with normal or abnormal renal tracts-were compared with controls. Acute UTI resulted in raised sIgA, IgA and FSC compared with controls (GOM ratio of 4.9 [p < 0.002], 4.2 [p < 0.005] and 2.7 [p < 0.001] respectively). The proportion of total IgA present as sIgA (sIgA/total IgA) was not significantly different in the acute vs control groups. Urinary sIgA and IgA may be important for the observed variation with age in infant UTI and the reduced incidence in breast fed infants but does not appear to contribute to the sex associated difference in susceptibility to infection at any age.

Measurement of salivary, urinary and fecal secretory IgA levels in children with partial or total IgA deficiency.

We measured salivary, urinary and fecal secretory IgA (sIgA) levels in 11 children with total IgA deficiency and in 6 children with partial IgA deficiency using an ELISA technique. This was based on flexible microplates coated with antisecretory component (SC) and peroxidase-conjugated anti-IgA as a second antibody. Selective IgA deficiency is diagnosed as a serum IgA concentration < or = 0.05 g/l; partial IgA deficiency is diagnosed as a serum concentration of IgA > 0.05 g/l but 2 SD below normal levels. No salivary or fecal sIgA, and only low levels of urinary sIgA, were detected in the selective IgA-deficient group. The partial IgA-deficient children presented with low levels of salivary, urinary and fecal sIgA. Fecal sIgA levels correlated with salivary sIgA levels (p < 0.01) but not with urinary sIgA levels (p > 0.05) in the IgA-deficient patients. We found that all the children with partial IgA deficiency, except one, had detectable, but low values of secretory IgA. Our data suggest that these patients also have a partial mucosal IgA deficiency.

Urinary secretory IgA after nutritional rehabilitation.

We studied the secretory IgA (sIgA) response of the mucosal urinary tract of malnourished children before and after nutritional rehabilitation. sIgA concentration (mg/l) was determined by ELISA in 187 children aged 3 months to 5 years. The children, who frequented a day care center, were divided into four groups, according to nutritional status: 57 were eutrophic, 49 were undergrown, 57 were moderately malnourished and 24 were severely malnourished. In addition, dip slide (Urotube, Roche) and dip-stick (Combur 9-Boehringer) tests showed that children had no bacteriuria or any other urinary abnormalities. Plasma albumin concentration (g/dl) was significantly lower (P < 0.005) in the severely malnourished group (mean 3.0 +/- 0.3 SD) than in the eutrophic group (mean 4.0 +/- 0.5 SD). When each nutritional state was analyzed, no significant differences in the sIgA were found between the 0 [symbol: see text]1 and 1 [symbol: see text]5 year age range. In the moderately and severely malnourished groups, sIgA (0.36 and 0.45, respectively) was significantly lower than in the eutrophic (0.69) and undergrown (0.75) groups. Ninety-five children were included in the 8-month follow-up study; 30 children were excluded from the follow-up because 4 had bacteriuria, 11 had leukocyturia, 8 had proteinuria and 7 had hematuria. Among the malnourished children, 40% showed nutritional improvement (P < 0.05) and significantly increased sIgA as compared to reference values for the eutrophic and undergrown groups. These data suggest that malnourished children have a significantly lower urinary sIgA than eutrophic children. After nutritional rehabilitation, they develop local immunity with a significant increase in sIgA.

[Value of antibody coated bacteria in the localization and follow-up of chronic urinary tract infections (author's transl)]. / Intérêt de la recherche des anticorps fixés sur les bactéries dans la localisation et la surveillance des infections urinaires chroniques.

Antibody coating of urinary bacteria was performed in order to localize the site of recurrent urinary tract infections in 39 para or tetraplegics. The antibody-coated bacteria test was positive with anti human globulin in 19 out of 39 patients: upper urinary tract infections 7/10, prostatitis 3/3, lower urinary tract infections 9/26. Of the 19 patients with positive antibody-coated bacteria test 14 were tested with monospecific antisera: 13 were IgG positive and 11 were IgA positive; IgM was never present. Among the 11 IgA positive tests, we search for the presence of IgA secretory piece in 8 and all were positive. The immunoglobulins on the bacterial wall result, in part, from local production of urinary antibody. Although positive results with anti human globulins occurred frequently in patients with lower urinary tract infections, this test appears to be a useful screening test for localization of infection in patients with recurrent urinary tract infection.

[Anti-bacterial defense mechanisms of the urinary tract constructed from intestinal segments. Preliminary studies on urinary tract infections, secretory IgA and composition of urine].

The characteristics of urinary tract infections (UTI), secretory IgA and urine composition of 24 patients (intestine group) who underwent operations using intestinal segments in urinary tract were compared with those of 26 complicated UTI patients without surgical intervention (control group). No significant differences were found in the frequency of either mono or polymicrobial infections between both groups. However, the frequency of bacterial isolation was different in the two groups, Streptococcus spp. and Providencia spp. were frequently isolated and P. aeruginosa was rarely isolated from the urine of the intestine group compared with from the urine of the control group. Furthermore, in polymicrobial infections of the intestine group with indwelling catheters, E. faecalis and Providencia spp. were frequently isolated simultaneously. The mean value of urinary secretory IgA was 94.0 micrograms/dl in the intestine group and 25.0 mu/dl in the control group (p less than 0.0001). The mean urinary osmolarity was 370 mOsm/kg in the intestine group and 500 mOsm/kg in the control group (p less than 0.005). The other parameters, including urinary pH and urea N concentration, showed no statistically significant differences. These findings suggest that urinary tract constructed from intestinal segments differs from the urinary tract without surgical intervention in the feature of UTI and anti-bacterial defense mechanisms.

[The local immunity of the urinary system in patients with recurrent urolithiasis]. / Sostoianie mestnogo immuniteta mochevoi sistemy u bol'nykh s retsidivnym urolitiazom.

51 patients with urolithiasis complicated by pyelonephritis in the active phase of inflammation were studied for the condition of local immunity by determining the urine content of secretory immunoglobulin A (SIgA) under conditions of combined treatment with making use of phlogenzyme, a drug of II-generation systemic enzymotherapy (SE). Recordable in this patients population was a marked increase in the urine level of SIgA. Incorporation in a combined treatment of phlogenzyme results in normalizing the status of the urinary system local immunity. Evidence has been obtained on the lack of parallelism in the dynamics between the serum IgA content and urine concentration of SIgA, which fact suggests independence of local immunity. Our theory is that an appreciable increase in the urine level of SIgA in patients with urolithiasis concurrent with pyelonephritis may have an important part to play in the genesis of nephrolithiasis.

Urinary sIgA in children with urinary tract infection.

Urinary secretory IgA (sIgA) was measured using a specific ELISA with insolubilized anti-IgA and enzyme-linked antisecretory component. This test was applied to unprocessed urine from healthy children and from children with urinary tract infection. Normal range was a function of age. In 175 healthy children the excretion rate of sIgA was low in infants younger than 6 months but was constant between ages 6 months to 15 years (median 0.69 mg/gm creatinine, range 0.15 to 3.4 mg/gm creatinine), whereas sIgA concentration (milligrams per liter of urine) increased continuously with age. No sex difference was noted. There were no significant circadian changes or day-to-day variability. Thirty girls, age 1 to 16 years, were examined; they had a history of recurrent symptomatic episodes of urinary tract infection but had anatomically normal tracts and no symptoms, and no bacteriuria at the time of study. sIgA excretion rate was significantly lower (0.45 mg/gm, creatinine, 0.08 to 0.75 mg/gm creatinine) than in controls. In contrast, 11 girls examined at the time of symptomatic urinary tract infections, and who had normal urinary tracts, had significantly (P less than 0.01) higher sIgA excretion rates (1.4 mg/gm creatinine, 0.8 to 3.4 mg/gm creatinine) than those in either control subjects or girls without symptoms at the time of study. Urinary sIgA excretion rates were highest (2.0 mg/gm creatinine, 0.44 to 3.69 mg/gm creatinine) in children with symptomatic urinary tract infections who had an abnormal urinary tract. We conclude that low urinary sIgA values may be a marker for recurrent symptomatic bacteriuria in girls with normal urinary tracts.

Breast feeding increases concentrations of IgA in infants' urine.

To investigate the influence of breast feeding on mucosal immunity the concentrations and daily outputs of IgA and lactoferrin in urine were measured in 10 breast fed and 12 infants fed on formula milk at 6 and 12 weeks of age. The concentrations and outputs of secretory IgA in urine were significantly higher in the breast fed group by a factor of three. The secretion of IgA in urine by the breast fed infants was characteristic of the baby and was not related to the intake of IgA from breast milk. Lactoferrin concentrations were similar in the two groups at both ages. In addition to secretory IgA, two thirds of all samples contained proteins with alpha chain but no secretory component antigenic determinants. Breast feeding seems to increase the local production of secretory IgA into the urinary tract during early childhood, thus providing enhanced protection from infection.