Biomarker analysis in polycythemia vera under interferon-alpha treatment: clonality, EEC, PRV-1, and JAK2 V617F.

Three consecutive polycythemia vera (PV) patients were analyzed before and during pegylated-interferon (rIFNalpha) treatment for the following markers: (1) granulocyte and CD34(+) cell clonality, (2) Jak2V617F expression, (3) PRV-1 mRNA overexpression, and (4) Epo-independent colony (EEC) growth. Before rIFNalpha therapy, all patients displayed clonal hematopoiesis, 100% Jak2V617F expression as well as PRV-1 overexpression, and EEC growth. After rIFNalpha treatment, all three patients demonstrated polyclonal hematopoiesis. Nonetheless, Jak2V617F expression, PRV-1 overexpression, and EEC-growth remained detectable, albeit at lower levels. We conclude that reemergence of polyclonal hematopoiesis after rIFNalpha treatment may be achieved in a substantial proportion of patients. However, this does not constitute elimination of the PV clone. These data demonstrate the usefulness of novel markers in monitoring minimal residual disease and caution against discontinuation of rIFNalpha treatment after hematologic remission. Long-term follow-up of large patient cohorts is required to determine whether rIFNalpha treatment can cause complete molecular remissions in PV.

STAT3 is constitutively active in some patients with Polycythemia rubra vera.

OBJECTIVE: Polycythemia vera is a clonal stem cell disorder characterized by hyperproliferation of the erythroid, myeloid, and megakaryocytic lineages. While it has been shown that progenitor cells of P. vera patients are hypersensitive to several growth factors including erythropoietin, insulin-like growth factor-1, thrombopoietin, interleukin-3, and granulocyte/monocyte colony-stimulating factor, the molecular pathogenesis of this disease remains unknown. Growth factor hypersensitivity could be mediated by changes in signal transduction pathways. We therefore investigated a common downstream effector of cytokines, the signal transducers and activators of transcription (STATs). A constitutive activation of STAT factors could explain the increased proliferation of P. vera cells even in the absence of growth factor stimulation. METHODS: Peripheral granulocytes from patients with P. vera and from healthy volunteers were assayed for STAT1, 3, and 5 DNA binding by electrophoretic mobility shift assay. RESULTS: Four of 14 P. vera patients analyzed showed constitutive STAT3 DNA binding in unstimulated peripheral granulocytes, while none of the 17 healthy volunteers tested did. None of the subjects showed constitutive STAT1 or STAT5 activity. Western blotting demonstrated that, in the three patients, STAT3 is constitutively phosphorylated on Tyr 705, whereas it is unphosphorylated in the other patients and in controls. Interestingly, constitutive STAT3 activity did not correlate with the duration of disease or the treatment regimen. It was observed in a recently diagnosed patient and in two patients treated only with phlebotomy. CONCLUSION: Our data suggest that constitutive phosphorylation and activation of STAT3 is not a secondary event induced by mutagenizing agents or by prolonged hyperproliferation of hematopoietic cells, but rather represents a primary molecular aberration. Constitutively active STAT3 may contribute to the growth factor hypersensitivity of P. vera cells.

Outcome of reoperative valve surgery via right thoracotomy.

BACKGROUND: The rate of patients being referred for mitral or tricuspid valve surgery after previous cardiac surgery is expected to increase. Reoperative median sternotomy has known risks, including injury to or embolism from prior grafts, sternal dehiscence, phrenic nerve injury, excessive hemorrhage, and inadvertent cardiac injury leading to morbidity and mortality. METHODS AND RESULTS: To avoid these problems, the right thoracotomy approach for reoperative mitral or tricuspid valve surgery was used in 62 patients from January 1990 to September 1995. Average patient age was 66 +/- 12 years. Previous operations included: coronary artery bypass graft, 31; mitral valve surgery, 26 (repair, 12, replacement, 14); and aortic valve surgery, 10. Patients were cannulated via the ascending aorta or common femoral artery with bicaval venous drainage. Systemic cooling and fibrillatory arrest were used. Operations performed included mitral valve repair in 27 patients; mitral valve replacement in 18; prosthetic mitral valve replacement in 14; repair of prosthetic mitral valve leak in 2; and tricuspid valve repair in 5. There was 1 intraoperative death and 4 other hospital deaths; 30-day hospital mortality was 6.4%. Complications were uncommon; only 1 patient required reexploration for bleeding. There have been 4 late deaths, and at a mean follow-up of 27 months (range, 1 to 69 months), survivors are in New York Heart Association class I or II. CONCLUSIONS: Right thoracotomy is a safe, feasible alternative to median sternotomy for selected reoperative mitral valve patients and should be considered whenever repeat sternotomy could prove hazardous.

Effect of extracorporeal life support on survival when applied to all patients with congenital diaphragmatic hernia.

Extracorporeal life support (ECLS) has been used for neonates with congenital diaphragmatic hernia (CDH) and respiratory failure at the authors' hospital since June 1981. In 1988, criteria for inclusion in ECLS were broadened to include "nonhoneymoon" infants (honeymoon: best postductal PaO2 of > 50 mm Hg). To evaluate the impact of this approach on the treatment of CDH, the authors reviewed the records of all newborns managed at their institution, since the availability of ECLS in 1981, who were symptomatic with CDH in the first 24 hours of life (n = 111). The patients were divided chronologically into two groups: 1981 to 1987 (early ECLS, n = 36) and 1988 to 1993 (expanded ECLS, n = 75). The data demonstrate that the number of CDH patients managed at our institution each year has increased (1981 to 1987 = 6, 1988 to 1993 = 14) as has the severity of associated respiratory insufficiency (% of patients with best PaO2 of < or = 50 mm Hg: 1981 to 1987 = 6%, 1988 to 1993 = 28%). Overall, the survival rate was lower for patients in the expanded ECLS group (59% v 75%; P = .121). When the survival rates for patients supported with ECLS postoperatively were compared for the expanded and early groups, a significant difference (59% v 80%; P < .05) was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal life support for adult cardiorespiratory failure.

BACKGROUND: Extracorporeal membrane oxygenation is routinely used for neonatal respiratory failure but is considered unsuccessful in adults based on old studies and old methods. We conducted a new phase 1 trial of modern extracorporeal life support (ECLS) in moribund adults with cardiorespiratory failure. METHODS: Criteria for initiation of ECLS were 90% mortality risk despite maximal conventional care, good potential for recovery, age < 60 years, and no contraindication to anticoagulation. Vascular access for ECLS was performed by operative or percutaneous cannulation. Continuous systemic heparinization was used, maintaining whole blood activated clotting time between 160 to 180 seconds. Blood components were transfused as necessary. Lung management included low rate and low pressure ventilation with an inspired oxygen fraction 0.5 or less. RESULTS: Forty patients were treated with ECLS, 30 with primary respiratory failure and 10 with primary cardiac failure. Twenty-two patients recovered lung or heart function, and 18 patients survived and were discharged from the hospital (14 with respiratory failure and four with cardiac failure, overall survival 45%). The major complication of ECLS was bleeding. CONCLUSIONS: With modern techniques, ECLS can be lifesaving in adult cardiorespiratory failure when conventional therapy has failed.

Neutrophils are not necessary for ischemia-reperfusion lung injury.

The role of neutrophils (PMNs) in ischemia-reperfusion injury after lung transplantation is unclear. If PMNs are involved in ischemia-reperfusion injury in the intact rat, then PMNs should sequester in the injured lung and PMN-depleted rats should develop less injury. Group A rats were treated with a rabbit anti-rat PMN antibody causing profound neutropenia (less than 100 PMNs/microL) and group B with control serum (greater than 2,000 PMNs/microL). Rats were anesthetized and left lung ischemia was sustained for 90 or 180 minutes by clamping the bronchus and the pulmonary artery and vein. Lung injury was quantified by the accumulation of radiolabeled (125I) albumin in ischemic left and nonischemic right lungs (cpm per gram of lung/cpm per gram of blood). Ischemia caused significant lung injury (p less than 0.05) in both PMN-depleted (albumin leak index: 90 min, 0.208; 180 min, 0.218) and nondepleted (90 min, 0.222; 180 min, 0.241) animals compared with nonischemic controls (depleted: 90 min, 0.050; 180 min, 0.100; nondepleted: 90 min, 0.063; 180 min, 0.101); microscopy also demonstrated lung injury. The injury was not associated with PMN sequestration as shown by light microscopy. Thus, we conclude that PMNs are not necessary for ischemia-reperfusion injury and PMN-depletion does not attenuate ischemia-reperfusion injury.