Prognostic factors for mature natural killer (NK) cell neoplasms: aggressive NK cell leukemia and extranodal NK cell lymphoma, nasal type

BACKGROUND

Patients with natural killer (NK) cell neoplasms, aggressive NK cell leukemia (ANKL) and extranodal NK cell lymphoma, nasal type (ENKL), have poor outcome. Both diseases show a spectrum and the boundary of them remains unclear. The purpose of this study is to draw a prognostic model of total NK cell neoplasms.

PATIENTS AND METHODS

We retrospectively analyzed 172 patients (22 with ANKL and 150 with ENKL). The ENKLs consisted of 123 nasal and 27 extranasal (16 cutaneous, 9 hepatosplenic, 1 intestinal and 1 nodal) lymphomas.

RESULTS

Complete remission rate for ENKL was 73% in stage I, but 15% in stage IV, which was consistent with that for ANKL (18%). The prognosis of ENKL was better than that of ANKL (median survival 10 versus 1.9 months, P < 0.0001) but was comparable when restricted to stage IV cases (4.0 months, P = 0.16). Multivariate analysis showed that four factors (non-nasal type, stage, performance status and numbers of extranodal involvement) were significant prognostic factors. Using these four variables, an NK prognostic index was successfully constructed. Four-year overall survival of patients with zero, one, two and three or four adverse factors were 55%, 33%, 15% and 6%, respectively.

CONCLUSION

The current prognostic model successfully stratified patients with NK cell neoplasms with different outcomes.

The expression profile of functional regulatory T cells, CD4+CD25high+/forkhead box protein P3+, in patients with ulcerative colitis during active and quiescent disease

Regulatory T cells (T(reg)) have an essential role in maintaining immune tolerance in the gut. The functional CD4(+) T(reg) express the transcription factor forkhead box protein 3 (FoxP3) or a CD25(high) in humans. Further, depletion of elevated granulocytes/monocytes by extracorporeal adsorption (GMA) induces immunomodulation in patients with ulcerative colitis (UC). We investigated the impact of GMA on T(reg). Thirty-one UC patients, clinical activity index (CAI) 12.1 +/- 2.97, refractory to conventional medications including intravenous corticosteroid and 13 healthy controls (HC), were included. Patients received five GMA sessions over 5 weeks. Biopsies from the rectal mucosa and blood samples at baseline and post-GMA were immunostained with anti-CD4/FoxP3 and anti-CD4/CD25 antibodies for immunohistochemistry and flow cytometry. Following GMA, 22 of 31 patients achieved remission (CAI <or= 4, P < 0.01) and their endoscopic activity index decreased from 10.6 +/- 2.32 to 4.75 +/- 1.48 (P = 0.003). The circulating CD4(+)CD25(high+) T(reg) level was low and increased markedly in responders (P < 0.02). In the nine non-responders, the baseline CD4(+)CD25(high+) T(reg) level was about 50% of the level in the responders (P < 0.03) or in the HC (P < 0.01), and all nine had to undergo colectomy. Conversely, the number of CD4(+)/FoxP3(+) mucosal T(reg) in GMA responders decreased significantly after the fifth GMA session compared with the baseline level (P < 0.05). It is believed that the CD4(+) T(reg) has an essential role in the control of immune pathology in UC patients and a net influx of these cells from the circulation into the mucosa may proceed to suppress inflammation. GMA can impact the circulating as well as the mucosal levels of T(reg).

Prophylactic fresh frozen plasma may prevent development of hepatic VOD after stem cell transplantation via ADAMTS13-mediated restoration of von Willebrand factor plasma levels

We initially conducted a multicenter, randomized trial (n=43), and subsequently a questionnaire study (n=209) of participating hospitals, to evaluate whether infused fresh frozen plasma (FFP) could prevent the occurrence of hepatic veno-occlusive disease (VOD) after stem cell transplantation (SCT). Forty-three patients were divided into two groups: 23 receiving FFP infusions and 20 not receiving it. VOD developed in three patients not receiving FFP. Plasma von Willebrand factor (VWF) antigen levels were lower at days 0, 7 and 28 after SCT in patients receiving FFP than in those not receiving it, whereas plasma ADAMTS13 activity (ADAMTS13:AC) did not differ between them. Plasma VWF multimer (VWFM) was demonstrated to be defective in the high approximately intermediate VWFM during the early post-SCT phase, but there was a significant increase in high VWFM just before VOD onset. This suggests that a relative enzyme-to-substrate (ADAMTS13/high-VWFM) imbalance is involved in the pathogenesis of VOD. To strengthen this hypothesis, the incidence of VOD was apparently lower in patients receiving FFP infusions than in those not receiving it (0/23 vs 3/20) in the randomized trial. Further, the results combined with the subsequent questionnaire study (0/36 vs 11/173) clearly showed the incidence to be statistically significant (0/59 vs 14/193, P=0.033).