Characteristics of respiratory syncytial virus-induced bronchiolitis co-infection with Mycoplasma pneumoniae and add-on therapy with montelukast

BACKGROUND

The influence of Mycoplasma pneumoniae (MP) infection on bronchiolitis remains unclear. Additionally, reports on the efficacies of leukotriene receptor antagonists in the treatment of bronchiolitis have been inconclusive.

METHODS

Children with respiratory syncytial virus (RSV)-induced bronchiolitis were divided into two groups: RSV+MP group and RSV group. Each group was randomly divided into two subgroups: one received routine and placebo treatment, while the other received routine and montelukast treatment for 9 months. The cumulative numbers of wheezing episodes and recurrent respiratory tract infections were recorded. Blood parameters were determined.

RESULTS

Patients in the RSV+MP group exhibited an older average age, fever, more frequent flaky and patchy shadows in chest X-rays, more frequent extrapulmonary manifestations, and longer hospital stays compared with patients in the RSV group. Additionally, higher baseline blood eosinophil counts, eosinophil cationic protein (ECP), total immunoglobulin E (IgE), interleukin (IL)-4, IL-5, IL-4/interferon-γ ratios, leukotriene (LT) B4, and LTC4, and lower baseline lipoxin A4 (LXA4)/LTB4 ratios were observed in the RSV+MP group compared with the RSV group. Montelukast treatment decreased the cumulative numbers of recurrent wheezing episodes and recurrent respiratory tract infections at 9 and 12 months. This efficacy may be related to the montelukast-induced reductions in peripheral eosinophil counts, ECP and total IgE, as well as the montelukast-dependent recovery in T helper (Th) 1/Th2 balance and LXA4/LTB4 ratios in children with bronchiolitis.

CONCLUSIONS

RSV bronchiolitis with MP infection was associated with clinical and laboratory features that differed from those of RSV bronchiolitis without MP infection. Add-on therapy with montelukast for 9 months was beneficial for children with bronchiolitis at 9 and 12 months after the initiation of treatment.

Add-on therapy with montelukast in the treatment of Henoch-Schönlein purpura

BACKGROUND

Previous studies suggested that leukotrienes (LT) were involved in the pathogenesis of Henoch-Schönlein purpura (HSP). This study investigated the efficacy of an add-on therapy with montelukast in the treatment of HSP.

METHODS

In this four-center, double-blind, placebo-controlled, parallel paired comparative study, 130 children with HSP were divided into two large groups: 84 patients without nephritis and 46 patients with nephritis. For each pair of patients with the same severity of disease, one subject was randomly allocated to one subgroup and the other allocated to the other subbroup; one subgroup received routine treatment plus placebo treatment, while the other subgroup received routine treatment plus montelukast treatment for 3 months. The efficacy was determined using Severity Scale Score (SSS). Blood eosinophil count, eosinophil cationic protein (ECP), IgE, interleukin (IL)-4, IL-5, IL-6, IL-8, IL-17, LTB4 , and urinary LTE4 were measured.

RESULTS

Add-on therapy with montelukast alleviated the symptoms of HSP including purpura, abdominal pain, stool occult blood, arthritis, proteinuria and hematuria, and, accordingly, shortened the length of hospital stay, and lowered blood eosinophil count, ECP, IgE, IL-4, IL-5, IL-6, IL-8, IL-17, LTB4 , and urinary LTE4 production, and also lowered the HSP relapse rate during the 3 months of treatment, but did not alter the outcome of nephritis at the end of follow up.

CONCLUSIONS

Add-on therapy with montelukast alleviated the symptoms of HSP. HSP may be improved by add-on therapy with a leukotriene receptor antagonist.

Inverse temporal changes of lipoxin A4 and leukotrienes in children with Henoch-Schönlein purpura

The pathogenesis of Henoch-Schönlein purpura (HSP) is not clearly understood. It remains unclear how changes of lipoxin A(4) (LXA(4)) that acts as a "braking signal" in inflammatory process occur in patients with HSP. In this study, we determined the temporal changes of blood and urinary LXA(4), Leukotriene (LT)B(4) and urinary LTE(4) in 49 children with HSP. Inverse temporal changes between gradually increased blood and urinary LXA(4) and gradually decreased blood and urinary LTB(4) and urinary LTE(4) were found in patients with HSP. Furthermore, both 15-S-hydroxyeicosatetraenoic acid and LXA(4) inhibited the LTB(4)-induced chemotaxis of leukocytes and release of LTB(4) from leukocytes obtained from the patients in the active phase of HSP. In 22 children with HSP nephritis, concordant with the gradually increased severity of mesangial proliferation and proteinuria, the glomerular expressions of 15-lipoxygenase and the levels of urinary LXA(4) gradually decreased and the glomerular expressions of LTC(4) synthase and the urinary LTE(4) and LTB(4) gradually increased. The levels of blood and urinary LXA(4) in patients with HSP nephritis were lower than those in patients with purpura alone in early resolution of HSP. The levels of blood and urinary LTB(4) and urinary LTE(4) in the patients with HSP nephritis were higher than those in patients with purpura alone in early resolution of HSP. There was positive correlation between blood LTB(4) and serum C-reactive protein in 49 children with HSP. These data suggest that LTs may play a proinflammatory and profibrotic role in the pathogenesis of HSP, and insufficiency of LXA(4) may be responsible for the patients with HSP whose illness become more serious.

Elevated expressions of 15-lipoxygenase and lipoxin A4 in children with acute poststreptococcal glomerulonephritis

Anti-inflammatory effects of the 15-lipoxygenase (15-LO) derivatives lipoxin A(4) (LXA(4)) and 15-S-hydroxyeicosatetraenoic acid (15-S-HETE) have been documented in many experimental models of acute inflammation. However, the expression levels of 15-LO and its products in human renal diseases remain unknown. This study investigated the expression levels of LXA(4), leukotriene B(4) (LTB(4)), and 15-LO in leukocytes and glomeruli obtained from 22 children with acute poststreptococcal glomerulonephritis (APSGN), and determined the modulatory effects of both 15-S-HETE and LXA(4) on LTB(4) synthesis in leukocytes and LTB(4)-evoked chemotaxis of polymorphonuclear leukocytes (PMNs) obtained from children during the first 3 days after onset of APSGN. Expression levels of both LXA(4) and 15-LO in leukocytes and glomeruli were up-regulated during the acute phase of disease, further peaking between days 10 and 14, and remained increased after 6 to 8 weeks of APSGN onset. In contrast, blood and urinary levels of LTB(4) as well as the number of glomerular PMNs peaked during the acute phase of disease and then decreased during the resolution phase. Administration of both 15-S-HETE and LXA(4) in vitro inhibited LTB(4)-induced chemotaxis of PMNs and production of LTB(4) from leukocytes obtained from patients with APSGN. The current study provides further support for an anti-inflammatory role for 15-LO products in human nephritis through both antagonism and inhibition of leukotriene synthesis and its biological activity.

Signal transduction involved in protective effects of 15(R/S)-methyl- lipoxin A(4) on mesangioproliferative nephritis in rats

Studies have shown that lipoxin A(4) (LXA(4)) inhibited proliferation of mesangial cells in vitro induced by platelet-derived growth factor, epidermal growth factor, leukotriene D(4) or tumor necrosis factor-alpha. In this study, we investigated the protective effects of 15(R/S)-methyl-LXA(4) on mesangioproliferative nephritis in rats and the signal transduction involved in actions of 15(R/S)-methyl-LXA(4). Mesangioproliferative nephritis was induced by a single intravenous injection of the mouse monoclonal anti-Thy1.1 antibodies. The nephritic rats were treated by intravenous injection of 15(R/S)-methyl-LXA(4) every 8h until the rats were sacrificed. There were increments in glomerular infiltration of leukocytes, expressions of protein and mRNA of interleukin (IL)-1beta and IL-6, activities of nuclear factor-kappaB (NF-kappaB) in nephritic rats from day 1 to 4 after induction of nephritis. The enhanced proteinuria, proliferation score of mesangial cells, glomerular proliferating cell nuclear antigen (PCNA) positive cells, activities of phosphorylated phosphoinositide 3-kinase (PI3-K), Akt(1), alpha-smooth muscle actin (alpha-SMA) and signal transducer and activator of transcription 3(STAT(3)), and reduced expression of p27(kip1) were found on day 4 after induction of nephritis. Treatment of nephritic rats with 15(R/S)-methyl-LXA(4) significantly reduced the protenuria, glomerular infiltration of leukocyte, expressions of protein and mRNA of IL-1beta and IL-6, proliferation score of mesangial cells, glomerular PCNA positive cells, activities of phosphorylated PI3-K, Akt(1), alpha-SMA, NF-kappaB and STAT(3), and ameliorated the decrement in p27(kip1) induced by anti-Thy1.1 antibodies. Protective effects of 15(R/S)-methyl-LXA(4) on nephritis induced by anti-Thy1.1 antibodies were related to PI3-K/Akt(1)/p27(kip1)/cyclin pathway, STAT(3) and NF-kappaB pathway-dependent signal transduction.

[Protective effects of 15-methyl-lipoxin A4 on mesangioproliferative nephritis in rats]

OBJECTIVE

To investigate the protective effects of 15-methyl-lipoxin A4 (LXA4) on mesangioproliferative nephritis in rats and the possible mechanisms.

METHODS

Mesangioproliferative nephritis was induced by a single intravenous injection of the mouse monoclonal anti-Thy1.1 antibodies (ER4) in 20 rats. Ten nephritic rats were injected with 15-methyl-LXA4 at 10 minutes before ER4 antibody injection and then 8-hourly until the rats were sacrificed on day 4 after nephritis induction. The nephritis was evidenced by presence of proteinuria, histologic examination with light microscopy, infiltrating leukocyte assessed by immunofluorescence microscopy, and mesangial cell proliferation assessed by proliferation scoring and by immunohistochemical staining of proliferating cell nuclear antigen (PCNA). Expressions of interleukin (IL)-1beta and IL-6 protein or mRNA in glomeruli were determined by radioimmunoassay or RT-PCR, respectively. Phosphorylated phosphoinositide 3-kinase (PI3-K), Akt1 and p27(kip1) in glomeruli were analyzed by Western Blot. Activities of nuclear factor-kappaB (NF-kappaB) and signal transducer and activator of transcription 3 (STAT3) in glomeruli were assessed by electrophoretic mobility shift assay (EMSA).

RESULTS

There were increases in glomerular infiltration of leukocyte, expressions of IL-1beta and IL-6 protein and mRNA, and activities of NF-kappaB in nephritic rats between days 1 and 4 after nephritis induction. The enhanced proteinuria, score of mesangial proliferation, glomerular PCNA positive cells, activities of phosphorylated PI3-K, Akt1 and STAT3, and reduced p27(kip1) expression were found on day 4 after nephritis induction. 15-Methyl-LXA4 treatment significantly reduced the proteinuria, glomerular infiltration of leukocyte, expressions of IL-1beta and IL-6 protein and mRNA, score of mesangial proliferation, glomerular PCNA positive cells, activities of phosphorylated PI3-K, Akt1, NF-kappaB and STAT3, and increased the p27(kip1) expression.

CONCLUSIONS

15-Methyl-LXA4 can markedly inhibit the proteinuria, glomerular inflammation, and mesangial cell proliferation induced by anti-Thy1.1 antibodies. The inhibition effects are related to PI3-K/Akt1/p27(kip1)/cyclin pathway, STAT3 and NF-kappaB pathway-dependent signal transduction.

[Serum levels of IL-5 and LTB4 in children with Henoch-Schonlein purpura]

OBJECTIVE

This study investigated the serum levels of interleukin-5 (IL-5), leukotriene B4 (LTB4) and C-reactive protein (CRP) in children with Henoch-Schonlein purpura (HSP) at different phases to explore the role of IL-5, LTB4 and CRP in the pathogenesis of HSP.

METHODS

Serum levels of IL-5, LTB4 and CRP in 27 normal children and 31 children with HSP at the acute phase and the early recovery phase were detected using ELISA.

RESULTS

The serum levels of IL-5, LTB4 and CRP in children with HSP were 53.8 +/- 4.2 pg/mL, 95.3 +/- 12.0 pg/mL and 36.10 +/- 11.78 mg/L, respectively at the acute phase. The values were significantly decreased at the early recovery phase (37.8 +/- 3.9 pg/mL, 45.7 +/- 10.1 pg/mL, 18.35 +/- 6.43 mg/L; P < 0.01), but remained higher than those in normal controls (12.7 +/- 3.2 pg/mL, 17.6 +/- 5.7 pg/mL, 4.75 +/- 2.85 mg/L; P < 0.01). The serum levels of IL-5 and LTB4 positively correlated to the CRP level.

CONCLUSIONS

The serum levels of IL-5 and LTB4 in children with HSP increased during the acute phase and decreased at the early recovery phase, suggesting that IL-5 and LTB4 may be involved in the pathogenesis of HSP.

Mutagenesis and expression of the E3-19k lumenal domain of adenovirus type 2

CD8+ T cells recognize viral or tumor antigens of 8-10 residues derived from cytosolic proteins that are bound to the class I molecules of the major histocompatibility complex (MHC). To escape this immune surveillance, adenovirus expresses a protein, E3-19k, that specifically down-regulates the cell surface expression of class I MHC molecules on infected cells. To most effectively manipulate the T-cell response to virus-infected cells, it is essential to understand the mechanism by which viruses, such as adenoviruses, down-regulate the class I MHC function. We have subcloned the lumenal domain of adenovirus E3-19k protein in order to characterize its interactions with the class I MHC molecules. Several point mutations have also been generated on the E3-19k lumenal domain with either the first 96 or 108 amino acids. Attempts to crystallize the complexes between E3-19k and class I MHC molecule had been initiated.

Endocrine and cytogenetic studies in a patient with Turner's phenotype and a ring chromosome

A 27-year-old woman with secondary amenorrhea and some of the somatic stigmata of Turner's syndrome was found to have a ring chromosome. Laparoscopy and ovarian biopsy showed hypoplastic ovaries and an absence of primordial follicles. Endocrine evaluation showed a normal 24-h mean LH level (12.5 mIU/ml), an elevated FSH level (28 mIU/ml) and a normal plasma estradiol level (64 pg/ml). The augmented FSH and normal LH response to LH-RH is similar to what is found in men with germinal cell aplasia (Sertoli-cell only). The synchronous initiations of normal LH and abnormally augmented FSH secretory episodes in this patient suggests the absence or decrease of some factor normally produced by the ovarian follicle which modulates the release of FSH in response to LH-RH.