Modern management of phagocyte defects

Phagocytic neutrophil granulocytes are among the first immune cells active at sites of infection, forming an important first‐line defense against invading microorganisms. Congenital immune defects concerning these phagocytes may be due to reduced neutrophil numbers or function. Management of affected patients depends on the type and severity of disease. Here, we provide an overview of causes and treatment of diseases associated with congenital neutropenia, as well as defects of the phagocytic respiratory burst.     

H-ficolin serum concentration and susceptibility to fever and neutropenia in paediatric cancer patients

H-ficolin (Hakata antigen, ficolin-3) activates the lectin pathway of complement similar to mannose-binding lectin. However, its impact on susceptibility to infection is currently unknown. This study investigated whether the serum concentration of H-ficolin at diagnosis is associated with fever and neutropenia (FN) in paediatric cancer patients. H-ficolin was measured by time-resolved immunofluorometric assay in serum taken at cancer diagnosis from 94 children treated with chemotherapy. The association of FN episodes with H-ficolin serum concentration was analysed by multivariate Poisson regression. Median concentration of H-ficolin in serum was 26 mg/l (range 6–83). Seven (7%) children had low H-ficolin (< 14 mg/l). During a cumulative chemotherapy exposure time of 82 years, 177 FN episodes were recorded, 35 (20%) of them with bacteraemia. Children with low H-ficolin had a significantly increased risk to develop FN [relative risk (RR) 2·24; 95% confidence interval (CI) 1·38–3·65; P = 0·004], resulting in prolonged duration of hospitalization and of intravenous anti-microbial therapy. Bacteraemia occurred more frequently in children with low H-ficolin (RR 2·82; CI 1·02–7·76; P = 0·045). In conclusion, low concentration of H-ficolin was associated with an increased risk of FN, particularly FN with bacteraemia, in children treated with chemotherapy for cancer. Low H-ficolin thus represents a novel risk factor for chemotherapy-related infections.     

PROCALCITONIN AND C-REACTIVE PROTEIN SERUM LEVELS AS MARKERS OF INFECTION IN A PEDIATRIC POPULATION WITH FEBRILE NEUTROPENIA AND CANCER

Background: Procalcitonin and C-reactive-protein are inflammatory markers for sepsis. The authors evaluated their sensitivity and specificity in pediatric patients with cancer and febrile neutropenia. Procedure: Serum procalcitonin and C-reactive-protein were evaluated. Patients (n = 54) were divided into 2 groups, with severe infection (n = 18) or without documented infection (n = 36). Results: Procalcitonin and C-reactive protein were significantly higher in the high-risk group. Procalcitonin displayed 72.2% sensitivity and 80.5% specificity. C-reactive-protein had a sensitivity of 77.7% and specificity of 77.2%. Conclusions: Procalcitonin is an accurate predictor of bacterial infection in neutropenic children, while C-reactive-protein may be a better screening test in emergency settings.     

Key Pharmacokinetic Parameters of Isepamicin in Febrile Neutropenic Cancer Patients and in Women with Acute Pelvic Inflammatory Disease

Abstract

The pharmacokinetics (PK) of isepamicin were studied in 8 febrile neutropenic patients with hematologic malignancy and in 20 young women with acute pelvic inflammatory disease (PID). Isepamicin was given as a slow intravenous infusion over 30 min at a dose of 15 mg/kg once daily (OD). Serum levels of isepamicin were determined by fluorescence polarization immunoassay, and PK analyses were obtained based on a one-compartment open model after 24 hours (steady state) and after 7 days.

On day 1, the volume of distribution (V_d) of isepamicin, for both populations, appeared about 30% higher than classically reported in healthy individuals: 0.31 and 0.36 L/kg for neutropenic and PID patients respectively. However on day 7, V_d displayed significant reduction (0.28 and 0.27 L/kg, respectively for neutropenic and PID patients). A reduction of isepamicin clearance was also observed between day 1 and day 7 (137 vs 120 mL/min and 130 vs 101 mL/min for neutropenic and PID populations, respectively). Such changes are consistent with a significant increase in the C_max concentrations (45 vs 50 mg/L, and 38 vs 49 mg/L) and in the AUC (136 vs 158 and 137 vs 162 mg/L.h) observed after a week of treatment in neutropenic and PID patients, respectively.

In conclusion, taking into account the importance of reaching early active concentrations, we recommend the use of higher loading dose of isepamicin (>15 mg/kg) in neutropenic cancer patients and in women with PID, particularly in case of a combination with a possibly ineffective antibacterial agent, in case of infection with bacteria at upper limit of susceptibility, in the presence of high infectious inoculum or in the presence of sequestered sites of infection.     

Transient neutropenia increases macrophage accumulation and cell proliferation but does not improve repair following intratendinous rupture of Achilles tendon

Neutrophils are the first leukocytes to invade tendons after an acute injury. They could modulate both the inflammatory response and early repair processes through the release of reactive species, cytokines, growth factors, and proteinases. However, the exact role of these cells in damaged tendons remains unclear. We investigated their role by inducing a transient neutropenia in C57BL/6 male mice using an anti‐Ly6C/Ly6G antibody. Placebo mice received only serum. The right Achilles tendon was sectioned and sutured using the 8‐strand technique, which allowed immediate weight bearing. A significant increase in macrophage accumulation and cell proliferation was observed in tendons from neutropenic animals compared to the placebo group at days 3 and/or 7 postinjury. However, there was a reduction in cell proliferation in a group of mice depleted in macrophages, indicating that macrophages play a role in cell replication in injured tendons. Lastly, the tendons of neutropenic and placebo mice had similar collagen content and mechanical properties at days 7, 14, and/or 28 postinjury. Our findings demonstrate that neutropenia modulates macrophage accumulation and cell proliferation, but overall, a reduction in neutrophil number has no significant effect on tendon repair. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1084–1091, 2010     

Effect of vitamin E on chemotherapy-induced mucositis and neutropenia in leukemic patients undergoing bone marrow transplantation

Aim: This study was conducted to investigate the effect of oral vitamin E on mucositis and neutropenia in patients with leukemia. Methods: This was a randomized double‐blind placebo controlled clinical trial of 60 patients with leukemia (acute lymphoblastic, acute myelogenous leukemia and chronic myelogenous leukemia) who were consecutive recipients of allogenic bone marrow transplantation (BMT), randomly assigned to receive 400 mg vitamin E twice daily (supplemented group) or placebo (control). The incidence and severity of mucositis and the mean duration of neutropenia were compared. Results: The mean duration of neutropenia and the incidence of the mucositis between the two groups was the same (P = 1.0). The difference between the placebo group and mucositis grade 1 (P = 0.31), grade 2 (P = 0.25), grade 3 (P = 0.93) and grade 4 (P = 0.32) was not statistically significant. Moreover the variables of age, sex, BMI and underlying disease had no effect. Conclusion: In this study supplementation with oral vitamin E had no effect on mucositis and neutropenia in patients with leukemia who were recipients of allogenic BMT. More interventional trials are warranted.     

盐酸伊立替康的不良反应及其预防处理

伊立替康(irinotecan,CPT-11)是喜树碱的半合成衍生物,是选择性拓扑异构酶Ⅰ抑制剂,本品及其体内代谢物SN-38可诱导单链DNA损伤,从而阻断DNA复制,产生细胞毒作用。CPT-11于1998年获FDA批准用于标准化疗方案治疗后转移性结肠直肠癌复发和恶化的二线治疗;于2000年3月获FDA批准联合氟尿嘧啶(5-FU)和亚叶酸钙(CF)用于转移性结肠直肠癌的一线治疗。本品单药有效率在18%左右,联合5-FU和CF的有效率约为50%。CPT-11主要不良反应有迟发性腹泻、恶心、呕吐、中性粒细胞减少症、急性胆碱能综合征等,现就其不良反应的表现类型及预防处理方法进行概述。     

Iso-immune neonatal neutropenia due to an anti-Fc receptor III (CD16) antibody

We report a case of transient neonatal neutropenia due to a maternal iso-immunization against a non polymorphic region of the glycosylphosphatidylinositollinked Fc receptor type III (CD16) on granulocytes. The mother's granulocytes were typed NA1-negative, NA2-negative and CD16-negative with human and monoclonal antibodies whereas her lymphocytes express the CD16 molecule. Expression of other markers were comparable to the controls. Flow cytometric analysis showed that maternal antibody recognized the granulocytes but not the lymphocytes from blood bank donors and that its binding was decreased on normal, phospholipase C-treated, granulocytes. The binding of commercial CD16 monoclonal antibodies was also dramatically decreased on normal granulocytes pre-incubated with maternal serum. The CD16 specificity of the antibody was confirmed by negative reactions with another CD16-deficient granulocytes. This observation leads us to conclude that celllineage specific differences of CD16 molecules are recognized by the patient's antibody. Moreover, we confirm that the absence of the FcRIII (CD16) on granulocytes is not associated with any pathology or susceptibility to infections and that, in the children, the blockade of this receptor by the maternal antibody only led to moderate neutropenia.