Interleukin-33/ST2 Axis as Potential Biomarker and Therapeutic Target in Kawasaki Disease.

Kawasaki disease (KD) is an acute, self-limiting, febrile systemic vasculitis of unknown cause associated with the development of coronary artery lesions (CALs) during childhood. Damage-associated molecular patterns (DAMPs) from cell death and oxidative stress have been shown to be involved in the development of KD vasculitis. Interleukin (IL)-33 is released from damaged endothelial cells and acts as a DAMP. We studied whether IL-33 and its receptor (ST2) might be involved in KD pathogenesis. Serum levels of soluble ST2 (sST2) in KD patients were measured before their first therapy. Furthermore, we investigated the impact of IL-33 on human coronary artery endothelial cells (HCAECs). Serum levels of sST2 were significantly higher in KD patients with CALs than in those with normal coronary arteries. In vitro, IL-33 upregulated the expression of ST2L and increased production of sST2, IL-6, IL-8, and monocyte chemoattractant protein-1 in HCAECs in a time- and concentration-dependent manner. Moreover, IL-33 induced significantly greater production of IL-6 and IL-8 in HCAECs compared to the condition stimulated with isoconcentration of tumor necrosis factor-α. The results of the present study suggest that the IL-33/ST2 axis might be involved in the development of KD vasculitis. The IL-33/ST2 axis may be a therapeutic target for the treatment of KD.

Safety and Feasibility of Infliximab Therapy in Children With Kawasaki Disease Who Received Live Vaccinations.

BACKGROUND: Kawasaki disease (KD) is an acute and febrile systemic vasculitis that occurs during childhood. Infliximab (IFX) is a chimeric monoclonal antibody that binds to tumor necrosis factor-α. Although IFX therapy is a useful option for refractory KD, vaccine-associated infections may develop after therapy. In Japan, IFX therapy is recommended after a duration of at least 3 months after live vaccinations or at least 6 months after Bacillus Calmette-Guérin (BCG) in children with KD. However, the appropriate duration between live vaccinations and IFX therapy is unclear. METHODS: We investigated children who developed KD within 3 months after live vaccinations or within 6 months after BCG. Clinical characteristics, side effects of therapies and efficacy of live vaccinations were retrospectively investigated. RESULTS: Forty-eight patients developed KD within 3 months of live vaccinations or within 6 months after BCG. Eight patients underwent IFX therapy. There were no apparent vaccine-associated infections. The patients who underwent IFX acquired protective IgG antibody titers in the 5 of 6 live vaccines. CONCLUSIONS: Safe and appropriate duration between live vaccinations and IFX therapy for KD patients could be shorter in the future, although more studies are warranted to establish the safe duration.

A novel mutation in early-onset sarcoidosis/Blau syndrome: an association with Propionibacterium acnes.

BACKGROUND: Early-onset sarcoidosis (EOS) and Blau syndrome (BS) are systemic inflammatory granulomatous diseases without visible pulmonary involvement, and are distinguishable from their sporadic and familial forms. The diseases are characterized by a triad of skin rashes, symmetrical polyarthritis, and recurrent uveitis. The most common morbidity is ocular involvement, which is usually refractory to conventional treatment. A gain-of-function mutation in the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene has been demonstrated in this disease; however, little is known about the relationship between the activation of NOD2 and the pathophysiology of EOS/BS. Here we describe EOS/BS with a novel mutation in the NOD2 gene, as well as detection of Propionibacterium acnes (P. acnes) in the granulomatous inflammation. CASE PRESENTATION: An 8-year-old Japanese girl presented with refractory bilateral granulomatous panuveitis. Although no joint involvement was evident, she exhibited skin lesions on her legs; a skin biopsy revealed granulomatous dermatitis, and P. acnes was detected within the sarcoid granulomas by immunohistochemistry with P. acnes-specific monoclonal (PAB) antibody. Genetic analyses revealed that the patient had a NOD2 heterozygous D512V mutation that was novel and not present in either of her parents. The mutant NOD2 showed a similar activation pattern to EOS/BS, thus confirming her diagnosis. After starting oral prednisolone treatment, she experienced an anterior vitreous opacity relapse despite gradual prednisolone tapering; oral methotrexate was subsequently administered, and the patient responded positively. CONCLUSIONS: We presented a case of EOS/BS with a novel D512V mutation in the NOD2 gene. In refractory granulomatous panuveitis cases without any joint involvement, EOS/BS should be considered as a differential diagnosis; genetic analyses would lead to a definite diagnosis. Moreover, this is the first report of P. acnes demonstrated in granulomas of EOS/BS. Since intracellular P. acnes activates nuclear factor-kappa B in a NOD2-dependent manner, we hypothesized that the mechanism of granuloma formation in EOS/BS may be the result of NOD2 activity in the presence of the ligand muramyl dipeptide, which is a component of P. acnes. These results indicate that recognition of P. acnes through mutant NOD2 is the etiology in this patient with EOS/BS.

Responses to Treatment According to the Cytokine Profiles of Pericardial Effusion in Two Children with Idiopathic Pericarditis.

Acute pericarditis is inflammation of the pericardium with or without pericardial effusion. In the pediatric population, most patients with acute pericarditis are diagnosed with idiopathic pericarditis. Herein, we present two children with idiopathic pericarditis who underwent immunological assessment of pericardial effusion for the first time. Both patients showed equally high levels of interleukin-6 in the pericardial effusion. However, they had different treatment responses, in accordance with the pericardial effusion and serum interleukin-10 concentrations. Our present cases suggest that interleukin-10 may be associated with the response to anti-inflammatory therapy in idiopathic acute pericarditis.

Pulmonary Hypertension Following Increased Dosing of Diazoxide in an Infant.

Diazoxide, a drug used to treat hyperinsulinemic hypoglycemia (HH), is associated with pulmonary hypertension (PH), as reported by the US Food and Drug Administration. However, no report has detailed the association between diazoxide dose and PH development. We report a case of an infant with HH, subsequently complicated by diazoxide-induced PH. When diazoxide was introduced, PH did not appear initially, but it developed during increased dosing. We monitored PH via regular echocardiography examinations. PH gradually improved with tapering of the diazoxide dose and disappeared after drug discontinuation. Our case suggests a diazoxide dose threshold might induce PH. Therefore, close echocardiography examinations should accompany diazoxide treatment.

Time-Course Evaluation of Body Mass Index in Japanese Children With Obstructive Sleep Apnea Syndrome After Adenotonsillectomy: A Three-Years Follow-Up Study.

Delayed physical growth is a common complication of pediatric obstructive sleep apnea syndrome (OSAS). Adenotonsillectomy (AT) is the first-line treatment for pediatric OSAS. Only a few studies have performed time-course BMI evaluation in pediatric OSAS patients post-operatively. Thus, we aimed to evaluate the time-course changes in pediatric OSAS patients after AT. Thirty-three children with OSAS who underwent AT were included and divided into two groups on the basis of their BMI z-scores (delayed physical growth group, n = 15; non-delayed physical growth group, n = 18). Clinical records of height and weight were collected before AT and at 6, 12, 24, and 36 months after AT. Changes in the mean BMI z-scores of the two groups were assessed up to 36 months. The mean BMI z-score was significantly increased in the delayed physical growth group at 6 months after AT. In contrast, the increase in mean BMI z-score was not observed in the non-delayed physical growth group. Growth improvement was noted in pediatric OSAS patients with delayed physical growth after AT. Our results suggest that AT is a promising therapy for improving the physical growth of pediatric OSAS patients with such problems.

Nonosmotic secretion of arginine vasopressin and salt loss in hyponatremia in Kawasaki disease.

BACKGROUND: The precise mechanism of hyponatremia in Kawasaki disease (KD) remains elusive because assessment of volume status based on serial changes in body weight is lacking in previous reports. METHODS: Seventeen patients who were diagnosed with KD and hyponatremia (serum sodium levels <135 mmol/L) were analyzed. Volume status was assessed based on serial changes in body weight. Plasma arginine vasopressin (ADH), urine electrolytes, and serum cytokine levels were measured on diagnosis of hyponatremia. An increase in body weight by >3% was defined as hypervolemia and a decrease in body weight by >3% was defined as hypovolemia. RESULTS: The volume status was hypervolemic in three patients (18%), euvolemic in 14 (82%), and hypovolemic in none (0%). Five (29%) patients were diagnosed with "syndrome of inappropriate secretion of antidiuretic hormone" (SIADH) and no patients were diagnosed with hypotonic dehydration. The contribution of decreased total exchangeable cations (salt loss) to hyponatremia (5.9% [interquartile range, 4.3%, 6.7%]) was significantly larger than that of increased total body water (-0.7% [-1.8%, 3.1%]) (P = 0.004). Serum interleukin-6 levels were elevated in all of the nine patients who were evaluated. Among the 12 (71%) patients who did not meet the criteria of SIADH and hypotonic dehydration, plasma ADH levels were inappropriately high in ten patients. These patients were also characterized by euvolemic or hypervolemic hyponatremia and salt loss, which might be compatible with a diagnosis of SIADH. CONCLUSIONS: Our study shows that hyponatremia in KD is euvolemic or hypervolemic and is associated with nonosmotic secretion of ADH and salt loss in the majority of patients.

Serum soluble ST2 as a marker of renal scar in pediatric upper urinary tract infection.

BACKGROUND AND OBJECTIVES: Upper urinary tract infection is the most common serious bacterial infection in childhood. Patients with upper urinary tract infection have a risk for renal scarring with subsequent complications including hypertension, proteinuria, and progressive renal failure. However, the predictive biomarkers of renal scarring in children with upper urinary tract infection are still unknown. In this study, we evaluated whether soluble ST2 levels can be biomarkers of subsequent renal scarring in patients with upper urinary tract infection. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: We retrospectively studied pediatric patients with upper urinary tract infection at a tertiary center. Twenty-eight children had an upper urinary tract infection with (n = 14) and without (n = 14) renal scarring and underwent 99mtechnetium dimercaptosuccinic acid imaging. In addition, 13 control subjects were enrolled. The clinical data and serum cytokine levels, including soluble ST2 levels, were compared between those with and without renal scars. RESULTS: Serum soluble ST2 levels were significantly higher in the scar group than in the non-scar group, whereas there was no difference in the levels of serum interferon-γ, interleukin-6, interleukin-10, soluble tumor necrosis factor receptor 1, and transforming growth factor-ß between the scar and non-scar groups. The area under the curve for differentiating between the non-scar and scar groups on the basis of measurements of serum soluble ST2 was 0.79, with a sensitivity and specificity of 92.9% and 64.3%, respectively. CONCLUSION: These results suggest that serum soluble ST2 levels on admission could be a useful biomarker of subsequent renal scarring in pediatric patients with upper urinary tract infection.

Early canakinumab therapy for the sensorineural deafness in a family with Muckle-Wells syndrome due to a novel mutation of NLRP3 gene.

Cryopyrin-associated periodic syndrome (CAPS) is one of the autoinflammatory disorders caused by mutations in NLRP3 gene. The over-production of interleukin (IL)-1ß induced by NLRP3 gene mutations plays an important role in the pathophysiology of CAPS. We diagnosed 3 patients with CAPS, who were lineal family members having a novel mutation of NLRP3 gene. The objective of this report is to compare the characteristics of symptoms and differences in the therapeutic responses of them, who had the same mutation. In addition, we aimed to examine the usefulness of cytokine measurement for diagnosis or determination of treatment effect of CAPS. A 5-year-old Japanese boy (proband) came to our hospital because of short stature, reached the diagnosis of Muckle-Wells syndrome (MWS) due to a mutation in NLRP3 gene, which had not been reported so far (p.G328E, c.G983A). His mother and grandmother harbored the same mutation of NLRP3. We measured serum concentrations of cytokines in the proband assessed by flow-cytometric bead array. All of them had episodic skin eruptions with conjunctivitis, hearing loss, and arthralgia, but not periodic fever, cold-triggered episodes, and chronic aseptic meningitis. Only the proband had short stature. Canakinumab therapy led to a prompt relief of symptoms and normalized laboratory data in all patients. Audiograms demonstrated an improved hearing level in the proband, but not two others despite of the same mutation. All cytokines did not show any characteristic findings. Sensorineural hearing loss and itchless rash but not serum cytokine profile deserved attention to the diagnosis and treatment start of CAPS. The early intervention of IL-1ß blockade may reduce the chance of complete deafness in patients with CAPS.

Suplatast tosilate for treating cutaneous mastocytosis.

Pediatric cutaneous mastocytosis is a rare disease caused by mast cell hyperplasia. We report the case of an infant diagnosed as cutaneous mastocytosis and seasonal allergies. The wheals, flushing, and pruritus of the mastocytosis were unresponsive to combination therapy with an antihistamine, a mast cell stabilizer (sodium cromoglycate), and a leukotriene antagonist. Addition of suplatast tosilate as a treatment for the seasonal allergy also dramatically improved his cutaneous symptoms and signs. Further trials of suplatast tosilate in selected cases of cutaneous mastocytosis are warranted.

3-D analysis of dislocation in zygoma fractures.

OBJECTIVE: When fractured, zygomas rotate and dislocate. The present study quantitatively elucidates the pattern of the rotation. METHODS: 50 patients with tri-pod-type zygoma fractures were involved in this study. After defining a 3-dimensional coordinate system--consisting of the M-L axis (the axis directed from the medial to lateral side of the skull), I-S axis (directed from the inferior to superior side), and P-A axis (directed from the posterior to anterior side), the degree with which the fractured zygomas rotated around each of these axes was measured using 3-dimensional graphic software. Thereafter, the tendency of the rotation was compared between the three rotational axes. RESULTS: Rotation around the I-S axis was the most frequent with a 96% incidence, followed by a substantial margin by rotation around the M-L axis with a 26% incidence; rotation around the P-A axis was rare, with an incidence of 10%. Furthermore, the degree of P-A axis rotation was minor compared to I-S and M-L axis rotations. CONCLUSION: The main factor of zygoma dislocation in zygoma fracture is rotation around the I-S axis. This finding is helpful for effective performance to reposition fractured zygomas.

Short Stat5-interacting peptide derived from phospholipase C-ß3 inhibits hematopoietic cell proliferation and myeloid differentiation.

Constitutive activation of the transcription factor Stat5 in hematopoietic stem/progenitor cells leads to various hematopoietic malignancies including myeloproliferative neoplasm (MPN). Our recent study found that phospholipase C (PLC)-ß3 is a novel tumor suppressor involved in MPN, lymphoma and other tumors. Stat5 activity is negatively regulated by the SH2 domain-containing protein phosphatase SHP-1 in a PLC-ß3-dependent manner. PLC-ß3 can form the multimolecular SPS complex together with SHP-1 and Stat5. The close physical proximity of SHP-1 and Stat5 brought about by interacting with the C-terminal segment of PLC-ß3 (PLC-ß3-CT) accelerates SHP-1-mediated dephosphorylation of Stat5. Here we identify the minimal sequences within PLC-ß3-CT required for its tumor suppressor function. Two of the three Stat5-binding noncontiguous regions, one of which also binds SHP-1, substantially inhibited in vitro proliferation of Ba/F3 cells. Surprisingly, an 11-residue Stat5-binding peptide (residues 988-998) suppressed Stat5 activity in Ba/F3 cells and in vivo proliferation and myeloid differentiation of hematopoietic stem/progenitor cells. Therefore, this study further defines PLC-ß3-CT as the Stat5- and SHP-1-binding domain by identifying minimal functional sequences of PLC-ß3 for its tumor suppressor function and implies their potential utility in the control of hematopoietic malignancies.

Phospholipase C-ß3 regulates FcɛRI-mediated mast cell activation by recruiting the protein phosphatase SHP-1.

Mast cells are major effectors in high-affinity IgE receptor (FcɛRI)-dependent allergic reactions. Here we show that phospholipase C (PLC)-ß3 is crucial for FcɛRI-mediated mast cell activation. Plcb3(-/-) mice showed blunted FcɛRI-dependent late-phase, but not acute, anaphylactic responses and airway inflammation. Accordingly, FcɛRI stimulation of Plcb3(-/-) mast cells exhibited reduced cytokine production but normal degranulation. Reduced cytokine production in Plcb3(-/-) cells could be accounted for by increased activity of the negative regulatory Src family kinase Lyn and reduced activities of the positive regulatory protein kinases MAPKs. Mechanistically, PLC-ß3 constitutively interacts with FcɛRI, Lyn, and SHP-1 (protein phosphatase). SHP-1 probably recognizes its substrates Lyn and MAPKs via the recently described kinase tyrosine-based inhibitory motif, KTIM. Consistent with PLC-ß3- and SHP-1-mediated repression of Lyn activity by dephosphorylation at Tyr396, FcɛRI-mediated phenotypes were similar in Plcb3(-/-) and SHP-1 mutant mast cells. Thus, we have defined a PLC-ß3- and SHP-1-mediated signaling pathway for FcɛRI-mediated cytokine production.

Tumor suppression by phospholipase C-beta3 via SHP-1-mediated dephosphorylation of Stat5.

Given its catalytic activity to generate diacylglycerol and inositol 1,4,5-trisphosphate, phospholipase C (PLC) is implicated in promoting cell growth. However, we found that PLC-beta3-deficient mice develop myeloproliferative disease, lymphoma, and other tumors. The mutant mice have increased numbers of hematopoietic stem cells with increased proliferative, survival, and myeloid-differentiative abilities. These properties are dependent on Stat5 and can be antagonized by the protein phosphatase SHP-1. Stat5-dependent cooperative transformation by active c-Myc and PLC-beta3 deficiency was suggested in mouse lymphomas in PLC-beta3(-/-) and in Emicro-myc;PLC-beta3(+/-) mice and human Burkitt's lymphoma cells. The same mechanism for malignant transformation seems to be operative in other human lymphoid and myeloid malignancies. Thus, PLC-beta3 is likely a tumor suppressor.