Molecular characterization of a carbon dioxide-dependent Escherichia coli small-colony variant isolated from blood cultures.

A carbon dioxide-dependent small-colony variant of Escherichia coli SH4888 was isolated from blood cultures of a patient with cholangitis. To date, little is known regarding the molecular mechanisms leading to formation of carbon dioxide-dependent phenotypes in clinical isolates, but abnormalities in the carbonic anhydrase are thought to cause carbon dioxide autotrophy. In this study DNA sequence analysis of the carbonic anhydrase-encoding can locus in the carbon dioxide-dependent E. coli SH4888 revealed that the isolate had a 325-bp deletion spanning from the 3'-terminal region of can to the 3'-terminal region of hpt, which encodes a hypoxanthine phosphoribosyltransferase. To confirm that the carbon dioxide-dependent SCV phenotype of E. coli SH4888 was due to the can mutation, we performed a complementation test with a plasmid carrying an intact can that restored the normal phenotype. However, E. coli SH4888 had increased virulence compared to the can-complemented E. coli SH4888 in a murine infection model. In conclusion, these data confirm that impaired carbonic anhydrase function can cause a carbon dioxide-dependent SCV phenotype in E. coli SH4888 and provides a fitness advantage in terms of infection.

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.

Effect of i.v. immunoglobulin in the first 4 days of illness in Kawasaki disease.

BACKGROUND: Although early treatment of Kawasaki disease (KD) with i.v. immunoglobulin (IVIG) is expected to prevent coronary artery abnormalities, the effectiveness of IVIG by day 4 of illness remains to be determined. METHODS: This was a multi-institutional, retrospective cohort study. Patients diagnosed with KD at ≤4 days of illness were divided into two groups: those who received initial IVIG before and on day 5 of illness. Baseline characteristics were adjusted using propensity scores. The primary endpoint was the need for additional treatment. RESULTS: Of 339 patients diagnosed with KD by day 4, 181 and 158 received IVIG before and on day 5 of illness, respectively. Patients in the early treatment group had more adverse prognostic factors: infancy, early onset of the principal symptoms, and abnormal laboratory data. We thus adjusted baseline characteristics before treatment decisions using propensity scores. Propensity score matching of the two groups yielded 100 observations. More patients required additional treatment in the matched early treatment group: 37% vs 24% (adjusted OR, 1.7; 95%CI: 1.06-2.8; P = 0.047). The difference was more pronounced for risk of relapse after initial resolution of fever: 14% vs 5.0% (adjusted OR, 3.2; 95%CI: 1.3-7.7; P = 0.02). The risk of coronary artery lesion did not differ significantly. CONCLUSIONS: IVIG treatment by day 4 of illness is associated with the requirement for additional treatment even after adjustment of baseline characteristics. Increased resistance to IVIG when given by day 4 should be considered in order to improve the treatment regimen for early-diagnosed KD.

Novel Risk Assessment Tool for Immunoglobulin Resistance in Kawasaki Disease: Application Using a Random Forest Classifier.

BACKGROUND: Resistance to intravenous immunoglobulin (IVIG) therapy is a risk factor for coronary lesions in patients with Kawasaki disease (KD). Risk-adjusted initial therapy may improve coronary outcome in KD, but identification of high risk patients remains a challenge. This study aimed to develop a new risk assessment tool for IVIG resistance using advanced statistical techniques. METHODS: Data were retrospectively collected from KD patients receiving IVIG therapy, including demographic characteristics, signs and symptoms of KD and laboratory results. A random forest (RF) classifier, a tree-based machine learning technique, was applied to these data. The correlation between each variable and risk of IVIG resistance was estimated. RESULTS: Data were obtained from 767 patients with KD, including 170 (22.1%) who were refractory to initial IVIG therapy. The predictive tool based on the RF algorithm had an area under the receiver operating characteristic curve of 0.916, a sensitivity of 79.7% and a specificity of 87.3%. Its misclassification rate in the general patient population was estimated to be 15.5%. RF also identified markers related to IVIG resistance such as abnormal liver markers and percentage neutrophils, displaying relationships between these markers and predicted risk. CONCLUSIONS: The RF classifier reliably identified KD patients at high risk for IVIG resistance, presenting clinical markers relevant to treatment failure. Evaluation in other patient populations is required to determine whether this risk assessment tool relying on RF has clinical value.

Fever pattern and C-reactive protein predict response to rescue therapy in Kawasaki disease.

BACKGROUND: Evidence to guide rescue therapy in refractory Kawasaki disease (KD) is lacking. The aim of this study was to determine the most important variables in predicting non-response to rescue therapy in refractory KD. METHODS: We retrospectively analyzed 171 patients diagnosed with refractory KD resistant to initial i.v. immunoglobulin (IVIG). Participants received rescue therapy consisting of IVIG monotherapy or IVIG plus prednisolone. Characteristics and laboratory variables were compared between rescue therapy non-responders and responders. Multivariate logistic regression analysis was performed to determine the independent predictors of non-response to rescue therapy. RESULTS: Among the 171 participants, 54 (31.6%) were non-responders to rescue therapy. On univariate analysis, fever pattern after initial IVIG, day of illness at rescue therapy, rescue therapy regimen and six laboratory variables (pre-IVIG sodium, C-reactive protein [CRP]; post-IVIG white blood cell count, platelet count, sodium, CRP) were useful in discriminating between non-responders and responders. These nine variables were included in multivariate logistic regression analysis. Persistent fever after initial IVIG (aOR, 2.39; 95%CI: 1.07-5.37) and post-IVIG CRP (aOR, 1.09; 95%CI: 1.02-1.17, per 1 mg/dL increase) were identified as independent predictors of non-response to rescue therapy. IVIG rescue monotherapy (aOR, 3.05; 95%CI: 1.05-8.84) also predicted non-response after adjusting for fever pattern and post-IVIG CRP. CONCLUSIONS: Persistent fever and elevated CRP after initial IVIG are predictive of non-response to rescue therapy for refractory KD. For patients at high risk of non-response, IVIG plus prednisolone, or even further intensified rescue therapy regimens may be preferable.

Early occurrence of nephrotic syndrome associated with cord blood stem cell transplantation.

Nephrotic syndrome (NS) associated with hematopoietic stem cell transplantation (HSCT) is usually related to chronic graft-versus-host disease (GVHD) and invariably occurs later than 100 days after transplantation. Here, we report the case of a 6-year-old boy who presented with NS only 61 days after cord blood stem cell transplantation (CBSCT). At 4 years old he was diagnosed with acute lymphoblastic leukemia and underwent bone marrow transplantation. Six months later, a recurrence was noted in the thymus, which required CBSCT at the age of 6. Acute GVHD and hemophagocytic syndrome occurred on day +13 and day +15, respectively, and were successfully treated with tacrolimus and a steroid. After tacrolimus was switched from intravenous infusion to oral administration, NS occurred on day +61. Complete remission was achieved in 3 weeks by resuming steroid treatment. Dry erythema with pigmentation and elevation of Th2 cytokine level suggest that NS in this case was also related to chronic GVHD. To our knowledge, this is the earliest occurrence of NS after HSCT. Hematologists and nephrologists should be aware that this condition may occur even in early periods after HSCT.

Survival in a neonate with complete urorectal septum malformation sequence after fetal vesico-amniotic shunting for a prominently dilated cloaca.

Complete urorectal septum malformation sequence (URSMS) is usually a lethal anomaly that is characterized by urethral obstruction, imperforate anus, ambiguous genitalia, renal agenesis or dysplasia, and mullerian duct maldevelopment. This anomaly is thought to be caused by the cessation of urorectal septum migration toward the caudal cloacal membrane. Teratogenic factors or a genetic abnormality is postulated as the etiology. To date, only 4 patients with URSMS have survived the neonatal period; however, 2 of these infants died before the age of 1 year. We report the survival in a case with complete URSMS who had moderate pulmonary hypoplasia and preserved left renal function. The cloacal remnant was dilated more than expected because the wall of the muscle layer was torn, perhaps in early fetal life, and timely placement of vesico-amniotic shunts prevented severe pulmonary hypoplasia caused by oligohydramnios.

Long-term survival of a baby with body stalk anomaly: report of a case.

Body stalk anomaly is characterized by severe scoliosis, severe pulmonary hypoplasia, and giant omphalocele. The prognosis of the disease is poor and most obstetricians consider it fatal. Very few patients with body stalk anomaly survive. We report the case of a baby diagnosed with body stalk anomaly in fetal life, who was saved by intensive care after birth. We closed the giant omphalocele successfully by placing karaya gum sheets over it, which created a humidified environment and promoted natural skin epithelization over the skin defect.

[A female case of hyper-IgM immunodeficiency syndrome with uncommon skin manifestations].

A 11-year-old female admitted to our hospital because of erythema of the face and the trunk, and a wide and dense cluster of verruca vulgaris on the right sole. She had no family history of immunodeficiency, no perinatal abnormality, no growth abnormality, or no history of severe infections. From the age of 4 years, she noticed erythema around her nose. At the age of 9 years, small erythema and papules appeared on her chest. In January, 2003, erythema around her nose and papules of the trunk spread rapidly, and she also felt fatigue and effort dyspnea. Laboratory examinations revealed near absence of serum IgG, and IgE, high serum IgM (525 mg/dl), and normal IgA and IgD. Thl/Th2 ratio was 36.9. We diagnosed her as having hyper-IgM syndrome. Histological examinations of a skin biopsy showed the infiltration composed of mainly histiocytes,and mildly atypical CD8 + T cells around the blood vessels in the dermis. We concluded her skin manifestations as reactive lymphohistiocytic infiltration at the base of immunodeficiency and durable stimulation of various antigens. Her skin manifestations improved transiently by the intravenous immunogrobulin and corticosteroids therapy.