Hemovigilance and the Notify Library

Hemovigilance systems allow reporting of adverse occurrences associated with blood transfusion to a central database where events can be reviewed and analyzed for the benefit of patients and donors. Hemolytic and serologic transfusion reactions are among the many types of reactions reported to these systems. The Notify Library, a database of adverse events associated with medical products of human origin, has incorporated hemovigilance into its didactic resources. Students and practitioners are encouraged to use the electronic library and to further enhance this resource through review and recommendation of additional publications in the area of immunohematology. Hemovigilance systems allow reporting of adverse occurrences associated with blood transfusion to a central database where events can be reviewed and analyzed for the benefit of patients and donors. Hemolytic and serologic transfusion reactions are among the many types of reactions reported to these systems. The Notify Library, a database of adverse events associated with medical products of human origin, has incorporated hemovigilance into its didactic resources. Students and practitioners are encouraged to use the electronic library and to further enhance this resource through review and recommendation of additional publications in the area of immunohematology.

Identifying a newly discovered HLA-C allele, HLA-C*02:138

A new allele, now named HLA-C*02:138, was discovered during testing of a registry donor for possible stem cell transplantation.

Identifying a newly discovered HLA-C allele: HLA-C*07:607

Phased sequencing identified the HLA-C*07:607 allele in an African-American patient and sibling donor.

Undetectable negative tissue transglutaminase IgA antibodies predict mucosal healing in treated coeliac disease patients

BACKGROUND

Tissue transglutaminase (tTG) immunoglobulin A (IgA) testing is a sensitive adjunct to the diagnosis of coeliac disease. The threshold for positivity was developed for diagnosis, with negative results reported as below the reference value (<4 U/mL).

AIM

To investigate if an undetectable (tTG IgA<1.2 U/mL) is more predictive of healing compared to patients with negative but detectable serology (1.2-3.9 U/mL).

METHODS

We performed a retrospective study of 402 treated coeliac disease patients seen at the Mayo Clinic with negative tTG IgA values drawn within 1 month of duodenal biopsy between January 2009 and December 2015. The Corazza-Villanacci score was used to assess mucosal healing. The presence of gastrointestinal symptoms was also collected. Logistic regression was used to assess the relationship of clinical variables with a normal biopsy.

RESULTS

Patients with undetectable titres more frequently had normal duodenal histology compared to patients with detectable tTG IgA levels (117/240 vs. 53/162; OR=1.96; 1.292, 2.961). Asymptomatic patients more frequently had normal duodenum as compared to symptomatic patients (88/163 vs. 82/239; OR=2.25; CI: 1.494, 3.377). Patients with undetectable serology and on a gluten-free diet for ≥2 years were more likely to have no villous atrophy compared to patients with detectable serology (148/192 vs. 55/88; OR=2.02; CI: 1.17, 3.49).

CONCLUSION

In subjects recovering from coeliac disease with negative tTG IgA serology, an undetectable titre is associated with normal histology on follow-up biopsy.

Liver Allograft Provides Immunoprotection for the Cardiac Allograft in Combined Heart-Liver Transplantation

When transplanted simultaneously, the liver allograft has been thought to have an immunoprotective role on other organs; however, detailed analyses in simultaneous heart-liver transplantation (SHLT) have not been done to date. We analyzed patient outcomes and incidence of immune-mediated injury in 22 consecutive SHLT versus 223 isolated heart transplantation (IHT) recipients between January 2004 and December 2013, by reviewing 3912 protocol- and indication-specific cardiac allograft biopsy specimens. Overall survival was similar (86.4%, 86.4%, and 69.1% for SHLT and 93.3%, 84.7%, and 70.0% for IHT at 1, 5, and 10 years; p = 0.83). Despite similar immunosuppression, the incidence of T cell-mediated rejection (TCMR) was lower in SHLT (31.8%) than in IHT (84.8%) (p < 0.0001). Although more SHLT patients had preexisting donor-specific HLA antibody (22.7% versus 8.1%; p = 0.04), the incidence of antibody-mediated rejection was not different in SHLT compared with IHT (4.5% versus 14.8%, p = 0.33). While the left ventricular ejection fraction was comparable in both groups at 5 years, the incidence and severity of cardiac allograft vasculopathy were reduced in the SHLT recipients (42.9% versus 66.8%, p = 0.03). Simultaneously transplanted liver allograft was associated with reduced risk of TCMR (odds ratio [OR] 0.003, 95% confidence interval [CI] 0-0.02; p < 0.0001), antibody-mediated rejection (OR 0.04, 95% CI 0-0.46; p = 0.004), and cardiac allograft vasculopathy (OR 0.26, 95% CI 0.07-0.84; p = 0.02), after adjusting for other risk factors. These data suggest that the incidence of alloimmune injury in the heart allograft is reduced in SHLT recipients.

Positive crossmatch kidney transplant recipients treated with eculizumab: outcomes beyond 1 year

This study examined outcomes beyond 1 year in eculizumab-treated (EC) positive crossmatch kidney transplants (+XMKTx) compared to a historical control group. +XMKTx received desensitization with either plasma exchange (PE) alone (N = 48) or PE and EC (N = 30). EC, given for at least 1 month, was continued in the setting of persistently high DSA (B flow cytometric crossmatch [BFXM] >200) including: 4 weeks (n = 14); 9 weeks (n = 6), 6 months (n = 2), and 12 months (n = 8). All patients had at least 2 years follow-up. The incidence of acute clinical ABMR was lower in the EC group than controls (6.7% vs. 43.8% p < 0.01). Death-censored allograft survival was similar between groups. Chronic ABMR was the main cause of graft loss. On 1-year protocol biopsies, no differences were noted between EC and controls including: cg score >0, 26.7% versus 31.9% (p = 0.62), ptc score ≥ 2, 60.0% versus 60.0% (p = 1.00), or C4d + , 33.8% versus 13.5% (p = 0.08). A persistently high BFXM in EC-treated patients was associated with cg score >0 at 1 year, while EC appeared to protect against cg if the BFXM remained low. We conclude that despite decreasing acute clinical ABMR rates, EC treatment does not prevent chronic ABMR in recipients with persistently high BFXM after +XMKTx.

Acute pancreas allograft rejection is associated with increased risk of graft failure in pancreas transplantation

The effect of acute allograft rejection (AR) on long-term pancreas allograft function is unclear. We retrospectively studied 227 consecutive pancreas transplants performed at our institution between January 1, 998 and December 31, 2009 including: 56 simultaneous pancreas and kidney (SPK), 69 pancreas transplantation alone (PTA); and 102 pancreas after kidney (PAK) transplants. With a median follow-up of 6.1 (IQR 3-9) years, 57 patients developed 79 episodes of AR, and 19 experienced more than one episode. The cumulative incidence for AR was 14.7%, 19.7%, 26.6% and 29.1% at 1, 2, 5 and 10 years. PTA transplant (hazards ratio [HR]=2.28, p=0.001) and donor age (per 10 years) (HR=1.34, p=0.006) were associated with higher risk for AR. The first AR episode after 3 months post PT was associated with increased risk for complete loss (CL) (HR 3.79, p<0.001), and the first AR episode occurring during 3- to 12-month and 12- to 24-month periods after PT were associated with significantly increased risk for at least partial loss (PL) (HR 2.84, p=0.014; and HR 6.25, p<0.001, respectively). We conclude that AR is associated with increased risk for CL and at least PL. The time that the first AR is observed may influence subsequent graft failure.

Five-year outcomes in living donor kidney transplants with a positive crossmatch

Renal transplant candidates with high levels of donor-specific anti-HLA antibodies have low transplantation rates and high mortality rates on dialysis. Using desensitization protocols, good short-term outcomes are possible in "positive crossmatch kidney transplants (+XMKTx)", but long-term outcome data are lacking. The aim of the current study was to determine actual 5-year graft outcomes of +XMKTx. We compared graft survival and the functional and histologic status of 102 +XMKTx to 204 -XMKTx matched for age and sex. Actual 5-year death-censored graft survival was lower in the +XMKTx group (70.7% vs. 88.0%, p < 0.01) and chronic injury (glomerulopathy) was present in 54.5% of surviving grafts. Graft survival was higher in recipients with antibody against donor class I only compared with antibody against class II (either alone or in combination with class I) (85.3% vs. 62.6%, p = 0.05) and was similar to -XMKTx (85.3 vs. 88.0%, p = 0.64). Renal function and proteinuria ranged across a wide spectrum in all groups reflecting the different histological findings at 5 years. We conclude that when compared to -XMKTx, +XMKTx have inferior outcomes at 5 years, however, almost half of the surviving grafts do not have glomerulopathy and avoiding antibodies against donor class II may improve outcomes.

Prevalence, course and impact of HLA donor-specific antibodies in liver transplantation in the first year

The presence of preformed donor-specific HLA antibodies (DSA) in liver transplant recipients is increasingly recognized; however, the prevalence of DSA and their impact on early allograft function remains unknown. We prospectively followed serum DSA levels of 90 consecutive liver transplant recipients from baseline to 4 months. Twenty recipients (22.2%) had preformed DSA. No antibody-targeting treatments were undertaken. Seven days after transplantation, DSA levels decreased markedly in all but three patients. Day 7 protocol biopsies showed diffuse C4d deposition along the portal stroma, central vein, subendothelial and stromal space in the patients with persistent high DSA levels. The rate of acute cellular rejection was not significantly different in patients with DSA. The transaminase and bilirubin levels remained comparable during the first year despite the presence of DSA. The three patients with persistently high DSA levels continue to have normal allograft function. We conclude that in most cases, DSA disappear after liver transplant, however in rare instances where they persist, there is evidence of complement activation in the liver allograft, without significant clinical impact in the first year.

Terminal complement inhibition decreases antibody-mediated rejection in sensitized renal transplant recipients

Sensitized renal transplant recipients with high levels of donor-specific alloantibody (DSA) commonly develop antibody-mediated rejection (AMR), which may cause acute graft loss or shorten allograft survival. We examined the efficacy of terminal complement inhibition with the humanized anti-C5 antibody, eculizumab, in the prevention AMR in renal transplant recipients with a positive crossmatch against their living donor. The incidence of biopsy-proven AMR in the first 3 months posttransplant in 26 highly sensitized recipients of living donor renal transplants who received eculizumab posttransplant was compared to a historical control group of 51 sensitized patients treated with a similar plasma exchange (PE)-based protocol without eculizumab. The incidence of AMR was 7.7% (2/26) in the eculizumab group compared to 41.2% (21/51) in the control group (p = 0.0031). Eculizumab also decreased AMR in patients who developed high levels of DSA early after transplantation that caused proximal complement activation. With eculizumab, AMR episodes were easily treated with PE reducing the need for splenectomy. On 1-year protocol biopsy, transplant glomerulopathy was found to be present in 6.7% (1/15) eculizumab-treated recipients and in 35.7% (15/42) of control patients (p = 0.044). Inhibition of terminal complement activation with eculizumab decreases the incidence of early AMR in sensitized renal transplant recipients (ClincalTrials.gov number NCT006707).

Baseline donor-specific antibody levels and outcomes in positive crossmatch kidney transplantation

Renal transplant candidates with donor-specific alloantibody (DSA) have increased risk of antibody-mediated allograft injury. The goal of this study was to correlate the risk of antibody-mediated rejection (AMR), transplant glomerulopathy (TG) and graft survival with the baseline DSA level (prior to initiation of pretransplant conditioning). These analyses include 119 positive crossmatch (+XM) compared to 70 negative crossmatch (-XM) transplants performed between April 2000 and July 2007. Using a combination of cell-based crossmatch tests, DSA level was stratified into very high +XM, high +XM, low +XM and -XM groups. In +XM transplants, increasing DSA level was associated with increased risk for AMR (HR = 1.76 [1.51, 2.07], p = 0.0001) but not TG (p = 0.18). We found an increased risk for both early and late allograft loss associated with very high DSA (HR = 7.71 [2.95, 20.1], p = 0.0001). Although lower DSA recipients commonly developed AMR and TG, allograft survival was similar to that of -XM patients (p = 0.31). We conclude that the baseline DSA level correlates with risk of early and late alloantibody-mediated allograft injury. With current protocols, very high baseline DSA patients have high rates of AMR and poor long-term allograft survival highlighting the need for improved therapy for these candidates.

Alloantibody levels and acute humoral rejection early after positive crossmatch kidney transplantation

We examined the course of donor-specific alloantibody (DSA) levels early after transplant and their relationship with acute humoral rejection (AHR) in two groups of positive crossmatch (+XM) kidney transplant recipients: High DSA group-41 recipients with a baseline T- or B-cell flow crossmatch (TFXM, BFXM) channel shift >or=300 (molecules of equivalent soluble fluorochrome units (MESF) of approximately 19 300) who underwent pretransplant plasmapheresis (PP), and Low DSA group-29 recipients with a baseline channel shift <300 who did not undergo PP. The incidence of AHR was 39% (16/41) in the High DSA group and 31% (9/29) in the Low DSA group. Overall, mean DSA levels decreased by day 4 posttransplant and remained low in patients who did not develop AHR. By day 10, DSA levels increased in patients developing AHR with 92% (23/25) of patients with a BFXM >359 (MESF of approximately 34 000) developing AHR. The BFXM and the total DSA measured by single antigen beads correlated well across a wide spectrum suggesting that either could be used for monitoring. We conclude that AHR is associated with the development of High DSA levels posttransplant and protocols aimed at maintaining DSA at lower levels may decrease the incidence of AHR.

X-linked thrombocytopenia caused by a novel mutation of GATA-1

A family with recessive X-linked thrombocytopenia affecting 4 males in 2 generations, characterized by macrothrombocytopenia, profound bleeding, and mild dyserythropoiesis, is described. Microsatellite linkage analysis identified a region of the X chromosome including the GATA-1 gene, which encodes a critical transcription factor involved in erythrocyte and megakaryocyte development. By sequencing the entire coding region of GATA-1, a 2-base mutation was detected that results in a single amino acid substitution (glycine 208 to serine) within a highly conserved portion of the N-terminal zinc finger domain. Restriction fragment length polymorphism confirmed that this novel mutation segregated with the affected males and female carrier. Although not required for DNA binding, Gly208 of GATA-1 is involved in direct interaction with Friend of GATA-1 (FOG), a cofactor required for normal megakaryocytic and erythroid development. These results demonstrate that the GATA-1-FOG interaction is partially disrupted by the mutation and that the greatest effect involves contact with the FOG zinc finger 9. These findings help describe a novel mutation of GATA-1 in humans as a cause of X-linked thrombocytopenia, and they confirm the vital role played by this transcription factor during in vivo megakaryocyte development.

Endothelial dysfunction: therapy revisited (brief excerpts) (round table discussion on 18/01/2001 at Mumbai)

Indians have highest incidence of coronary heart disease. Here it occurs much more prematurely. Endothelial dysfunction has been increasingly recognised as an early event for the development of various cardiovascular disease. Long acting nifedipine has a definite role to play in reversing endothelial dysfunction.

Hepatitis B virions isolated with antibodies to the pre-S1 domain reveal occult viremia by PCR in Alaska Native HBV carriers who have seroconverted

BACKGROUND

Occult viremia occurring before the appearance of HBsAg or after the disappearance of HBsAg is detectable by gene amplification technologies whose efficiency depends on nucleic acid preparation.

STUDY DESIGN AND METHODS

To isolate HBV DNA from viremic plasma, immunoaffinity capture (IAC) of intact HBV with biotinylated pre-S1 antibodies coupled to streptavidin-coated magnetic beads was evaluated. IAC was compared with a silica-gel method (Qiagen [QSG]) and its two modifications wherein the samples were heated with lysis buffer at 60(o)C for 10 minutes (QSG-60) or at 58 degrees C for 60 minutes with proteinase-K (QSG-PK). Each HBV DNA sample was tested by heminested PCR amplification of the HBV gene sequences. A total of 36 coded serum samples were tested, including three HBsAg-positive controls and 33 former chronic HBV carriers who had seroconverted (developed antibody to HBsAg [anti-HBs]). Commercially available seroconversion panels (PHM 907, 911, and 922) were similarly tested for window-period viremia.

RESULTS

In the 33 former chronic HBV carriers who had seroconverted, IAC revealed HBV DNA in 17 samples, whereas it was revealed in only 11 samples by QSG-PK (p = 0.031), 10 by QSG-60 (p = 0.016), and 9 by QSG (p = 0.0078). However, HBV DNA was not amplified from the 17 samples at 1-in-10 dilutions; thus, they were considered to have low-level viremia. IAC revealed HBV DNA as early as or earlier than the other methods in PHM 907, 911, and 922 panels.

CONCLUSION

IAC is apparently an optimal method of sample preparation for amplification of HBV DNA in patients in the pre-HBsAg window period, and for detecting low-level viremia persistent in several individuals who were former chronic HBV carriers who had seroconverted (developed anti-HBs).

Properties of cyanovirin-N (CV-N): inactivation of HIV-1 by sessile cyanovirin-N (sCV-N)

Cyanovirin-N (CV-N) is a novel anti-HIV protein isolated and characterized from a cyanobacterium Nostoc ellipsosporum. CV-N protein is a single 101 amino acid chain containing two intrachain disulphide bonds and considerable internal sequence duplication, but no significant homology to previously described proteins or to the transcription products of known nucleotide sequences. In solution, CV-N exists largely as a beta-sheet protein with internal two-fold pseudosymmetry. CV-N irreversibly inactivates diverse laboratory strains, primary isolates and clades of HIV-1, as well as strains of HIV-2 and simian immunodeficiency virus (SIV). CV-N binds with extremely high affinity to highly conserved binding site(s) on the viral envelope glycoprotein gp120, preventing virus-to-cell fusion, viral entry and infection of cells. The CV-N binding site appears to overlap, but is not identical with, the unique carbohydrate-dependent epitope 2G12, and may lie predominantly within an immunologically "silent" region of gp120. CV-N is undergoing preclinical development for topical anti-HIV prophylactic (e.g., microbicidal) applications to prevent sexual transmission of HIV. Since CV-N may be immunogenic in humans, methods for using CV-N for ex vivo inactivation of HIV in blood, plasma, or putative vaccines preferably would allow for its exclusion from biologicals for parenteral use. To explore this concept we biotinylated CV-N (bCV-N) and coupled it to streptavidin coated magnetic beads to provide a product which we termed sessile CV-N (sCV-N). When reacted with a laboratory strain and a primary isolate of HIV- 1, the sCV-N completely inactivated 100 TCID50 of the virus. However RT-PCR of the viral extracts indicated that only a fraction of the virus was removed by the sCV-N, leaving behind a relatively larger fraction of non-infectious virus in the supernatant which we designated as replication incompetent virions (RIV). It would be worthwhile investigating the role of RIV as a putative HIV vaccine.

Comparison of clinical outcome of fixed-dose subcutaneous low molecular weight heparin (tinzaparin) with conventional heparin in unstable angina: a pilot study

Forty patients who were hospitalized for unstable angina were randomized to receive treatment with either regular heparin (Group I) in conventional dose as continuous infusion for 5 days or fixed-dose low molecular weight heparin (LMWH) (Group II), 3500 units subcutaneous twice daily for a period of 5 days. Both the groups were evenly matched with regard to age, sex presence of risk factors and adjunctive drug therapy. The clinical endpoints at the end of 5 day therapy were: recurrence of angina, occurrence of myocardial infarction and need for urgent revascularization. In Group I, 6 out of 20 patients had recurrence of angina, of whom 3 required urgent coronary angiography and revascularization. In Group II, 4 out of 20 patients had recurrence of angina, of whom one patient required urgent angiography and angioplasty. There were no bleeding complications in either of the groups. The recurrent anginal episodes in the conventional heparin group correlated with low aPTT values at the time of angina. Thus, this pilot study suggests that LMWH is equally effective in the treatment of unstable angina, the advantage of LMWH being the ease of administration and no need for monitoring aPTT levels during therapy.

Percutaneous transluminal coronary angioplasty (PTCA) in unstable angina

We performed percutaneous transluminal coronary angioplasty in 33 highly selected patients of unstable angina, a majority of whom were initially stabilized by medical therapy. All these patients had single vessel disease with type A lesion. The initial success rate was 91% with recurrence of 17% at the end of 1 year.

Prognostic significance of predischarge 2D-echocardiography after first transmural myocardial infarction

Predischarge two dimensional echocardiography (2D Echo) was performed in 45 survivors of first transmural myocardial infarction to assess its value in predicting major cardiac complications (MCC) during convalescence. Wall motion score was derived for each patient by analysing endocardial motion in 11 left ventricular segments. In 18 months follow up 11 of 14 patients (78%) who had major cardiac complications had wall motion score of at least 5. Wall motion score of less than 5 was present in 29 of the 31 (94%) of patients in asymptomatic group. Non-invasively obtained wall motion score helps in risk stratification of survivors of AMI. Wall motion score at predischarge 2D Echo or more identifies high risk cases from a relatively asymptomatic group (Killip Class I & II).

Coronary arteriographic findings soon after non Q wave myocardial infarction

We performed early coronary arteriography in 27 patients (23 males, 4 females) having non Q wave MI. Infarct related vessel (IRV) was totally blocked in 25.9%, whereas 66.7% had severe residual stenosis (greater than or equal to 70%). Left main was involved in 7.5%, and at least 2 major coronary arteries were involved in 51.8%. Visible collaterals were seen in 11%. We feel, as compared to transmural MI, where total occlusion of IRV is common, the higher incidence of subtotal occlusion of IRV with severe residual stenosis, poor collaterals and significant involvement of at least one other major coronary artery may be responsible for observation of early recurrent ischemic episodes in non Q wave MI.

Pulsed Doppler derived indices in predicting noninvasively, pulmonary arterial pressures

The pulsed doppler (P.D.) signals obtained in RVOT just below the pulmonary leaflets were used to calculate acceleration time (AcT), pre-ejection period (PEP) and their ratios. These indices were correlated in 31 patients (2 1/2-49 yrs. age) having varying cardiac lesions to Pulmonary arterial pressure (P.A.P) measured during cardiac catheterisation. The mean values of AcT for those with normal PAP was 137 +/- 19.9ms, as compared to 105 +/- 37 ms in those in whom PAP greater than 20mm of Hg. (t = 3.0.p less than .01). The P value was less than 0.001 when comparison was between normal PAP and severe PH. The ratios of PEP upon AcT was 0.87 +/- 0.18 for normal PAP, as compared to 1.39 +/- 0.74 in those with PH (t = 0.31, p less than 0.01). The PEP/AcT predicted systolic PAP 35.49 PEP/AcT + 3.22 (r = 0.77, p less than 0.001). The mean PAP was best predicted by 23.94 PEP/AcT + 2.44 (r = 0.75, p less than 0.001). The quantitative assessment showed presence of presystolic 'a' wave in all with normal PAP; this was absent in all the 9 patients with severe PH (MAPA greater than 40mm of Hg.). We conclude that noninvasively obtained P.D. derived indices can help accurately to predict PAP.

Double-chambered right ventricle with pulmonary valve endocarditis

A rare case of isolated pulmonary valve endocarditis associated with a double-chambered right ventricle in a nonaddict, was diagnosed on two-dimensional echocardiography and cardiac catheterization and angiography. The patient was successfully operated and the above findings confirmed on the operation table.