Vancomycin-resistant enterococci with reduced daptomycin susceptibility in Singapore: prevalence and associated factors.

Prevalence of vancomycin-resistant enterococci (VRE) and use of daptomycin are increasing in Asia. To determine the prevalence of daptomycin non-susceptible enterococci (DNSE) and understand factors associated with reduced daptomycin susceptibility in VRE, we conducted a case-control study in a 1600-bed adult tertiary hospital in Singapore. All VRE isolates from inpatients in 2012 were tested for daptomycin susceptibility. Patients with VRE isolates of daptomycin minimum inhibitory concentration (MIC) ⩾3 µg/ml were classified as daptomycin-reduced susceptible VRE (DRS-VRE) and those with daptomycin MIC 4 µg/ml (DNSE). About half (135, 55%) had reduced susceptibility to daptomycin (MIC 3-4 µg/ml). None in the DS-VRE group had prior exposure to daptomycin. After adjusting for age, gender, comorbidity, hospitalization duration, surgical history, indwelling device use, and duration of antibiotic exposure in the prior 3 months, >1 movement between wards [odds ratio (OR) 0·35, 95% confidence interval (CI) 0·16-0·74, P = 0·006] and minocycline resistance (OR 0·45, 95% CI 0·25-0·84, P = 0·011) were independently associated with DRS-VRE. Our study suggests that daptomycin exposure, >1 movement between wards, and resistance to minocycline, were associated with reduced daptomycin susceptibility in VRE.

Measurement of macrophage marker in hyperhaemolytic transfusion reaction: a case report.

BACKGROUND: Hyperhaemolytic transfusion reaction (HHTR) has been well described in patients with sickle cell disease (SCD). It is characterised by a decrease in haemoglobin concentration to levels below those before transfusion and a fall in the absolute reticulocyte count. As red blood cells (RBC) alloantibodies are typically not detected in post-transfusion samples in acute forms of HHTR, we have previously proposed that both the transfused and autologous RBCs cells (HbSS/reticulocytes) are destroyed by activated macrophages. CASE REPORTS: We report a patient with SCD who presented with vaso-occlusive sickle cell crisis and developed a severe HHTR attributable to anti-Fy3. In addition to the usual supportive measures, the patient was treated with intravenous immunoglobulin (IVIG) and steroids. Serum ferritin levels were measured as an aspecific marker of macrophage activation. RESULTS: Steroids and IVIG were effective in managing HHTR. Ferritin levels were high at the time of haemolysis, (>10000 µg L(-1)) whereas recovery and cessation of haemolysis correlated with a decrease in ferritin levels. CONCLUSION: Serum ferritin values >10,000 µg L(-1) are considered pathognomic for conditions characterised by abnormal macrophage activation. In our case, serum ferritin levels correlate well with the disease activity and clinical response. This further supports our previous proposal that the activated macrophages play an important role in HHTR. Serum ferritin is a nonspecific marker of inflammation. A rapid specific bio-marker to measure the activity of macrophages in SCD in HHTR is desirable, and this area warrants further investigation.

Reducing the incidence of TRALI in the UK: the results of screening for donor leucocyte antibodies and the development of national guidelines.

BACKGROUND AND OBJECTIVES: Transfusion-related acute lung injury (TRALI) is associated with the passive transfusion of leucocyte antibodies in blood products. Blood Transfusion Services have adopted a number of different strategies for reducing the incidence of TRALI, but, while these have been successful, TRALI has not been completely eliminated. Many Transfusion Services have introduced leucocyte antibody screening of donors to further reduce TRALI. This report describes the results of donor leucocyte antibody screening within NHS Blood and Transplant and the guidelines that have been developed for Transfusion Services within the United Kingdom (UK) to reduce the incidence of TRALI. MATERIALS AND METHODS: Blood samples from newly recruited female apheresis donors were tested for human leucocyte antigens (HLA) class I and class II antibodies and granulocyte-specific antibodies. RESULTS: A total of 1157 female donors were evaluated. Three hundred and fifteen (27·23%) donors had HLA class I or II antibodies and were returned to red cell component donation. Fifty-seven (6·77%) of the remaining 842 donors were found to have granulocyte-specific antibodies of which 11 (1·31%) had HNA-specific antibodies. A total of 818 donors (70·70%) were accepted for platelet apheresis, 336 donors (29·04%) were returned to red cell component donation, and three donors with HNA-3a antibodies (0·26%) were deferred from therapeutic donation. CONCLUSIONS: Female donors with leucocyte antibodies were identified in a stratified screening programme. Donors with antibodies were either directed to red cell donation or deferred. This process, combined with other measures that have already been introduced, is anticipated to further reduce the incidence of TRALI.

How much residual plasma may cause TRALI?

Although passive infusion of plasma-rich components containing white blood cell (WBC) antibodies are responsible for majority of the reported transfusion-related acute lung injury (TRALI) cases, the minimum volume of residual plasma, which might trigger TRALI, is not known. We report three cases of TRALI where the implicated donor component contained between 10 and 20 mL of residual plasma. Two cases were related to transfusion of red blood cells prepared in optimal additive solution, and the other was related to transfusion of pooled buffy coat platelets. In the latter case, WBC antibodies that matched the patient's human leucocyte antigen (HLA) antigens were only found in one buffy coat donor (female) who contributed a buffy coat for pooled platelets preparation. Plasma prepared from pooling platelets was collected from a male donor. Laboratory investigation confirmed that in all three cases, the donors' serum contained three to four different HLA class 1-specific and class 11-specific antibodies that matched with the patient's HLA type. Our cases suggest that the residual plasma volume as small as 10-20 mL containing donor derived WBC antibodies may cause TRALI. The risk of TRALI remains, despite providing pooled platelets suspended in male donor plasma. The significance of multiple HLA antigen/antibody matching between donor and recipient in immune TRALI warrants further study.

Transfusion-related acute lung injury (TRALI) in an obstetric patient.

Transfusion-related lung injury (TRALI) is the leading cause of mortality following transfusion of blood products. Despite increasing awareness, the condition often remains unrecognised and therefore underreported. A 28-year-old with moderate preeclampsia had a post-partum haemorrhage following emergency caesarean section. Shortly after receiving three units of packed red cells she went into respiratory failure, which progressed to cardiac arrest. She was successfully resuscitated and made a slow but full recovery. Investigation through the National Blood Service confirmed the diagnosis of TRALI. TRALI is an increasingly common life-threatening complication of blood transfusion and should be included in the differential diagnosis of collapse in an obstetric patient who has recently received a blood product transfusion.

Management of pregnancy complicated by anti-hrB/anti-HrB.

Anti-hrB and anti-HrB are rare alloantibodies found predominantly in people of Black African descent. It has been assumed that strongly reacting examples of anti-hrB may cause hemolytic transfusion reactions, but precise information is limited. Anti-HrB is a clinically significant antibody and may cause hemolytic transfusion reactions and HDN. Selection of blood for transfusion support for patients with these alloantibodies, and especially with anti-HrB, imposes a special challenge in the United Kingdom. We report two antenatal patients (both patients were of the partial D phenotype DIII), one with anti-hrB, anti-Ce, and anti-D; the other,with anti-hrB and anti-D, who later formed anti-HrB. Transfusion support and the outcome of the pregnancies are discussed. A literature search confirms that,apart from some publications in abstract form,there is not much detailed clinical information available for either anti-hrB or anti-HrB. Further information and publications are warranted to gain more knowledge of these rare antibodies.

Trends in the expression of breastmilk 1993-2003.

The expression of breastmilk is an important strategy to enable mothers to continue exclusive breastfeeding. In some situations, for health or convenience, expressed breastmilk is required and infants fed this way still fall within the definition of exclusive breastfeeding. The aim of this study was to document the changes in rates of breastmilk expression between the first Perth Infant Feeding Study (PIFS I) in 1992-03 and PIFS II in 2002-03. The proportion of mothers expressing breastmilk peaked in the first six weeks, at 38% for PIFS I and 69% for PIFS II. The proportion of mothers who had expressed breastmilk had almost doubled in the decade between studies. The proportion of mothers expressing declined to about 28% of mothers at 22 weeks for PIFS II and slightly less in PIFS I. Breastmilk expression is a very useful skill to allow mothers to exclusively breastfeed until six months and should be taught to all mothers.

Intravenous immunoglobulin given to lymphoma patients with recurrent haemolytic transfusion reactions after transfusion of compatible blood.

Accelerated destruction of red cells after transfusion of compatible blood has been reported in both sickle cell disease (SCD) and non-SCD patients. We report three patients with lymphoma, all of whom had recurrent haemolytic transfusion reactions after receiving compatible red cell units. The direct antiglobulin test (DAT) was negative and there were no detectable red cell alloantibodies in either pre-transfusion or post-transfusion samples. As there was no evidence of red cell antibody-mediated haemolysis and response to oral steroids, a trial of intravenous immunoglobulin (IVIg) was given. Immediate cessation of haemolysis with sustained haemoglobin level was achieved in all cases. The response to IVIg in these cases suggests that IVIg should be tried when recurrent non-antibody mediated haemolytic transfusion reactions occur in patients with a lymphoid malignancy.

Autoimmune hemolytic anemia and a further example of autoanti-Kpb.

A 65-year-old Caucasian man with myelodysplasia was admitted with autoimmune hemolytic anemia and a Hb of 5.6 g/dL. The patient's serum contained anti-K; the DAT on the patient's RBCs reacted 3+ with anti-IgG and 3+ with anti-C3d. K- RBC units were transfused, but there was no sustained increase in Hb level. The samples were referred to the reference laboratory of the National Blood Service. The DAT results remained the same, with anti-K detected only in the serum. An eluate prepared from the patient's DAT-positive RBCs revealed anti-Kp(b) specificity. This study reports an unusual case of autoanti-Kp(b), which is different from previously published cases in that no free anti-Kp(b) was detectable in the serum.

Severe gestational (incidental) thrombocytopenia: to treat or not to treat.

Thrombocytopenia is common in pregnancy and is diverse in etiology. Immune thrombocytopenic purpura (ITP) may affect both mother and the newborn. Gestational (incidental) thrombocytopenia in an otherwise fit woman, at term is the most frequent type of thrombocytopenia and poses no clinical consequences for mother or infant. We report six women who presented with severe thrombocytopenia during pregnancy. Five were treated in late pregnancy, either with intravenous immunoglobulin (IVIg), or IVIg followed by steroids. There was no response, and four received a platelet transfusion during delivery. The platelet counts in all the infants were normal and the maternal thrombocytopenia resolved spontaneously after delivery in all cases. Our observations suggest that this is a group of patients with a severe form of gestational thrombocytopenia. The severe form of gestational thrombocytopenia appears to be rare, and recognition is important, as it may recur in subsequent pregnancies and does not require any therapeutic intervention.

Use of red cells preserved in extended storage media for exchange transfusion in anti-k haemolytic disease of the newborn.

Anti-k is a Kell-related antibody. There is little correlation between the maternal antibody titre and the severity of haemolytic disease of the foetus and newborn, and anaemia is usually associated with low bilirubin levels. Severe erythroblastosis has been reported with a low titre anti-k (IAT 8-16). We report a case of severe haemolytic disease of the newborn (HDN) due to anti-k. HDN was associated with a normal bilirubin level and reticulocytopenia. The foetus was monitored by ultrasound, and delivery by elective caesarean section (CS) was planned. The mother was admitted 1 week before the expected date of delivery, and the infant was delivered by urgent CS. The infant required exchange transfusion. As suitable plasma-reduced (k antigen(-)) red cell units were not readily available, k- SAGM red cell units (preserved in extended storage media: SAGM sodium chloride, adenine, glucose and mannitol) were provided. The post-transfusion Hb remained stable, and the infant did not require further transfusion support. Our findings (reticulocytopenia and normal bilirubin levels) support the hypothesis that the pathogenesis of anaemia and haemolysis in anti-k HDN may be similar to that in anti-K (suppression of erythropoesis and immune destruction of K+ erythroid progenitor cells by macrophages in the foetal liver). The ideal product for exchange transfusion is plasma-reduced RBC, less than 5-days old. We provided a 4-day-old SAGM red cell unit for exchange transfusion in a term infant, and this was uneventful. Caution should be taken, however, and renal function and electrolyte levels should be monitored closely. More information is required regarding the safety of SAGM units for exchange transfusion.

Decreased bispectral index as an indicator of syncope before hypotension and bradycardia in two patients with needle phobia.

We report two cases who exhibited a decrease in their bispectral index (BIS) score, associated with syncope during venipuncture in patients with suspected needle phobia. In case 1, the reduction in BIS score occurred during the development of hypotension and bradycardia and may well have been caused by cerebral hypoperfusion. In case 2, the patient lost consciousness with decreasing BIS score before hypotension and bradycardia; this patient's condition could not be completely explained by cerebral hypoperfusion as a result of a vasovagal reflex because the patient's blood pressure and heart rate remained normal during the syncopal episode.

Recurrent transfusion-related acute lung injury.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a rare condition that is commonly associated with the transfusion of donor plasma containing WBC antibodies. Biologically active lipids that accumulate during storage of RBCs and platelets may also cause TRALI. There has been only one previously reported case of recurrent TRALI. CASE REPORT: A patient received a transfusion 2 days after undergoing hysterectomy; she developed TRALI after receiving the transfusion. The patient recovered after being on ventilation for 6 days but received an additional transfusion and had a second episode of TRALI, which required further ventilation. RESULTS: Laboratory investigation of the first episode of TRALI suggested the presence of HLA-A2 (N = 1) and granulocyte-specific IgM antibodies (N = 2) in the sera from three of the donors. All three sera reacted in crossmatch studies with the patient's granulocytes and lymphocytes. Lymphocyte-specific IgG antibodies were detected in the patient's serum. There was no evidence to suggest the involvement of WBC antibodies in the second episode of TRALI. Antibody screening of the donors' samples and both forward and reverse crossmatch studies were negative. CONCLUSION: The first episode of TRALI seems to be due to the action of HLA-A2 and granulocyte-specific IgM antibodies. The second episode may have been due to the action of lipid neutrophil-priming agents in the donors' units in association with the patient's underlying pulmonary condition (i.e., recovering from lung injury). TRALI can recur if a patient requires further transfusion support shortly after an initial episode of TRALI.