Novel aspects of Kindlin-3 function in humans based on a new case of leukocyte adhesion deficiency III.

BACKGROUND: Kindlin-3 is a novel integrin activator in hematopoietic cells, and its deficiency leads to immune problems and severe bleeding, known as leukocyte adhesion deficiency III (LAD-III). Our current understanding of Kindlin-3 function primarily relies on analysis of animal models or cell lines. OBJECTIVES: To understand the functions of Kindlin-3 in human primary blood cells. PATIENTS/METHODS: We analyzed primary and immortalized hematopoietic cells obtained from a new LAD-III patient with immune problems, bleeding, a history of anemia, and abnormally shaped red blood cells. RESULTS: The patient's white blood cells (WBCs) and platelets showed defects in agonist-induced integrin activation and botrocetin-induced platelet agglutination. Primary leukocytes from this patient exhibited abnormal activation of ß(1) integrin. Integrin activation defects were responsible for the observed deficiency in the botrocetin-induced platelet response. Analysis of patient genomic DNA revealed a novel mutation in the Kindlin3 gene. The mutation abolished Kindlin-3 expression in primary WBCs and platelets, owing to abnormal splicing. Kindlin-3 is expressed in red blood cells (RBCs), and its deficiency is proposed to lead to abnormally shaped RBCs. Immortalized patient WBCs expressed a truncated form of Kindlin-3 that was not sufficient to support integrin activation. Expression of Kindlin-3 cDNA in immortalized patient WBCs rescued integrin activation defects, whereas overexpression of the truncated form did not. CONCLUSIONS: Kindlin-3 deficiency impairs integrin function, including activation of ß(1) integrin. Abnormalities in glycoprotein Ib-IX function in Kindlin-3-deficient platelets are secondary to integrin defects. The region of Kindlin-3 encoded by exon 11 is crucial for its ability to activate integrins in humans.

Primary Ewing tumor of the vertebrae: clinical characteristics, prognostic factors, and outcome.

BACKGROUND: Fewer than 10% of Ewing family of tumors (EFT) arise in the vertebrae. Little information is available regarding the clinical presentation and outcome of these tumors. PROCEDURE: We reviewed the clinical features, prognostic factors, and outcome of EFT of the spine identified at our institution between 1962 and 1999. RESULTS: Thirty-three (10%) of 344 patients with EFT had a primary vertebral tumor. There were 21 (64%) males. Median age at diagnosis was 13.3 years. Six patients had metastatic disease and 10 had tumors > or = 8 cm in diameter. Primary sites were sacral (13), thoracic (10), lumbar (8), and cervical (2) vertebrae. We found no association between the affected spinal region and outcome, although sacral tumors were associated with delayed diagnosis (4 vs. 2 months after onset of symptoms, P = 0.076). Pain (n = 32) and neurologic deficits (n = 31; 82% motor, 58% sensory, 42% bladder, 27% bowel) were the most common presenting features. All patients received combination chemotherapy and local radiotherapy. With a median follow up of 9.7 years, 5-year survival and event-free survival ( +/- SD) estimates were 48.1% (8.9%) and 35.6% (8.6%), respectively, comparable to those of other patients with EFT. Outcome was better for patients with tumor size < 8 cm (P = 0.008) or localized disease (P = 0.084). Treatment era and specific tumor site did not affect outcome. CONCLUSIONS: Outcomes are similar for primary EFT of the spine and primary EFT in other sites. Unlike others, we found that patients with sacral tumors did not fare worse than patients with tumors at other spinal sites.

Granulocyte-macrophage colony-stimulating factor in the treatment of neonates with neutropenia and sepsis.

To evaluate the efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) in improving neutrophil counts and survival of neutropenic septic neonates, the authors studied 8 neonates with gestational or postconceptional age at least 30 weeks; weight at least 1000 g; serious infection with concomitant neutropenia (absolute neutrophil count [ANC] < 3.0 x 10(9)/L) or leukopenia (white blood cell count < 5.0 x 10(9)/L) and anticipated survival at least 48 h. Patients received 5 micrograms/kg of GM-CSF intravenously for 5 consecutive days or until the ANC reached 20 x 10(9)/L. Clinical parameters and complete blood counts were monitored. Prestudy ANCs ranged from 0.05 to 2.7 x 10(9)/L. Four patients had positive blood cultures, 4 had necrotizing enterocolitis, and 1 was in septic shock. All patients had elevated C-reactive protein. All patients had resolution of neutropenia and survived the septic episodes. The use of GM-CSF in these patients merits further exploration.

Epstein-Barr virus infection in salivary gland tumors in children and young adults.

BACKGROUND: Epstein-Barr virus (EBV) infection has been implicated in the pathogenesis of certain subtypes of salivary gland tumors in the adult population. However, to the authors' knowledge its role in pediatric salivary gland tumors, a rare disease, has not been explored previously. METHODS: Thirteen cases of primary tumors of the salivary gland occurring in children were retrieved from the tumor registry at the St. Jude Children's Research Hospital in Memphis, Tennessee. Clinical data were analyzed from the medical records and formalin fixed, paraffin embedded tumor tissues were examined by the in situ hybridization (ISH) technique for the presence of latent EBV infection. RESULTS: Twelve of 13 tumors originated from the parotid gland and 1 originated from the submandibular gland. Mucoepidermoid carcinoma was the predominant tumor type; it was observed in seven patients, rhabdomyosarcoma was the diagnosis in three patients, acinic cell carcinoma was noted in two patients, and malignant fibrous histiocytoma was diagnosed in one patient. The ages of the patients ranged from 4.1-29.2 years, with a median age of 11 years. The outcome was excellent with all patients alive and free of disease at the time of last follow-up. The ISH tested negative in all tumor samples. CONCLUSIONS: Based on the results of the current study, EBV infection does not appear to play a major role in the pathogenesis of pediatric salivary gland tumors.

Mild hemophilia in children: prevalence, complications, and treatment.

PURPOSE: To review the natural history of mild hemophilia (factor VIII or IX level >5% and <50%), including presentation and diagnosis, characteristics of bleeding episodes, and therapy, at two hemophilia treatment centers. METHODS: Inpatient and outpatient records of 55 patients <17 years old with factor VIII or IX levels of 5 to 50% were reviewed and bleeding episodes for which medical attention was sought were analyzed. RESULTS: Five of the 55 patients were girls. Girls and patients with no family history of hemophilia were diagnosed at 5.5 and 5.3 years of age, respectively, compared to 2.8 years overall. Thirty-five patients were diagnosed because of a positive family history. No bleeding occurred in 18 patients; 190 bleeding episodes occurred in 37 patients. Most bleeding occurred in muscle/soft tissue (101 episodes) or joints (57 episodes) and were associated with trauma (174 episodes). CONCLUSIONS: Mild hemophilia may affect females more often than is appreciated. Delays in diagnosis and treatment may occur unless the variability in presentation is recognized.

Disseminated intrathoracic desmoplastic small round-cell tumor: a case report.

PURPOSE: Recently recognized as a distinct clinicopathologic entity, desmoplastic small round-cell tumors typically affect young men. These aggressive tumors usually arise in the abdomen; other sites of primary disease have been described only rarely. We report the case of an extraabdominal primary tumor with widespread dissemination, including the subcutaneous tissue, a previously unrecognized metastatic site. PATIENT AND METHODS: We describe the case of a 16-year-old boy with a primary extraabdominal metastatic desmoplastic small round-cell tumor. RESULTS: Our patient had a primary intrathoracic desmoplastic small round-cell tumor and widespread dissemination involving the subcutaneous tissue, kidney, liver, bone, and lymph nodes. Histopathologic analysis found intense desmoplasia and polyphenotypic expression of neural, muscle, and epithelial markers. Reverse transcriptase-polymerase chain reaction analysis of fresh tumor tissue confirmed the characteristic EWS-WT1 transcript. CONCLUSIONS: Broader than originally anticipated, the clinical spectrum of desmoplastic small round-cell tumors continues to evolve. Primary intrathoracic tumors with soft-tissue dissemination and polyphenotypic expression should prompt suspicion of this malignancy. Molecular analysis of fresh tumor tissue is an important adjunct to diagnosing this rare neoplasm.