Comparison of red blood cell hemolysis using plasma and serum separation tubes for outpatient specimens.

BACKGROUND: To rapidly obtain outpatient results, we use plasma separation tubes (PST) for chemistry analysis. If lactate dehydrogenase measurement is required, serum separation tubes (SST) are used. There has been no evaluation of hemolysis with these tubes. We compared the hemolytic index (HI) obtained by using PST and SST and applied this for choosing appropriate tubes for clinical laboratories. METHODS: The HI of specimens obtained from outpatients visiting Asan Medical Center between July and December 2012 was analyzed. The HI was scored from 0 to 10 by using the Toshiba 200FR (Toshiba Medical Systems Co., Japan). HI was classified by sample tube type, and significant hemolysis was defined as a HI of 2 or more. For significant hemolysis cases, medical records were reviewed to identify the causes. RESULTS: Among 171,519 specimens, significant hemolysis was observed in 0.66% of specimens (0.68% of PST specimens, 0.46% of SST specimens). The mean HI in PST was 0.18 (SD: 0.43) and that in SST was 0.14 (SD: 0.37). The proportion of significant hemolysis was significantly higher in PST than in SST (P=0.001). The cause of significant hemolysis was identified as chemotherapy and prosthetic valve in 48.1% of specimens. Complex sampling errors may have caused significant hemolysis in the remaining 51.9% of specimens. CONCLUSIONS: The incidence of hemolysis was slightly higher for PST than SST, although both were <1%. PST are thought to be more useful than SST in outpatient testing because of rapid turnaround time, greater sample volume, and less risk of random errors due to fibrin strands.

Significance of isoagglutinin titer in ABO-incompatible kidney transplantation.

ABO-incompatible (ABO-i) kidney transplantation (KT) has emerged for overcoming the shortage of organ donors. Although this technique initially achieved only low graft survival due to isoagglutinin, recently developed desensitization protocols have improved survival to levels that are comparable to ABO-compatible KT. However, isoagglutinin is still regarded as a major obstacle to ABO-i KT. In this study, we evaluate the impact of isoagglutinin titer on clinical outcomes as well as factors that may influence isoagglutinin titers. In total, data from 95 patients who underwent ABO-i KT were analyzed. Preoperatively, rituximab administration and plasmapheresis were performed until the titer was reduced to ≤1:4. Retrospective analysis included blood group; timing and dosage of rituximab; isoagglutinin titer; number of plasmapheresis; and clinical outcomes including graft survival and serum creatinine. Graft survival was 95.8% (n = 91) and average serum creatinine at 1- and 1.5-year post-ABOi-KT was 1.3. Three patients died of sepsis. The identified predictors of titer-rebound after transplant were short interval (<7 days) between rituximab and first plasmapheresis (P = 0.004); high initial titer (≥256) (P = 0.023); low titer-reduction rate (P < 0.001); and blood group O (P < 0.001). One patient who experienced a rebound developed antibody-mediated rejection. With low-dose (200 mg) rituximab, the change in isoagglutinin titer-rebound was not significant and the infection rate was significantly decreased (P = 0.001). In conclusion, isoagglutinin titer-rebound within the first 2 weeks after KT may be a risk factor for rejection. The factors identified as affecting titer-rebound after KT were high initial isoagglutinin titer, low titer-reduction rate, short interval, and blood group O.

The prognostic impact of c-KIT mutation in systemic mastocytosis associated with acute myeloid leukaemia patients.

We evaluate the haematopathologic features of systemic mastocytosis associated with acute myeloid leukaemia (SM-AML) and the prognostic role of c-KIT mutation. Total 11 patients were enrolled. Cytochemistry using toluidine blue and tryptase was positive, as was immunohistochemistry for CD117 and CD25 on clustered mast cells; however, CD2 was expressed in only nine cases. In 10 cases, RUNX1-RUNX1T1 fusion gene was detected, and one patient presented with a t(5;6)(q22;q23) translocation at diagnosis. The c-KIT mutation D816V was detected in six patients. Patients with c-KIT mutations had higher relapse and death rates than those without; 4/5 (80.0%) and 5/6 (83.3%) vs. 1/5 (20%) and 2/5 (40%), respectively. Overall survival was also significantly shorter in cases with, than those without, c-KIT mutations. To identify rare cases of SM-AML, which have a dismal prognosis, c-KIT mutation study and careful examination for the presence of clustered mast cell infiltration by immunochemistry should be performed.

OBFC2A/RARA: a novel fusion gene in variant acute promyelocytic leukemia.

Acute promyelocytic leukemia is characterized by the rearrangement of the retinoic acid receptor α (RARA) gene and its fusion with other genes. We report a novel case of variant acute promyelocytic leukemia with the karyotype der (2)t(2;17)(q32;q21). Array comparative genomic hybridization revealed distinct chromosome breakpoints within the RARA and oligonucleotide/oligosaccharide-binding fold containing 2A (OBFC2A) genes. Sequence analysis of the OBFC2A/RARA transcript showed that exon 5 of OBFC2A was fused with exon 3 of RARA through the same breakpoint as in previously described fusions of RARA. The single-stranded DNA binding protein encoded by OBFC2A is critical for genomic stability. Retention of the OB fold domain of OBFC2A in the fusion protein suggests the possibility of homodimerization. The leukemic cells from the patient showed neutrophilic differentiation in the in vitro all-trans retinoic acid assay. Mutation or rearrangement of the OBFC2A gene has not been previously reported in congenital or acquired disorders.

Subtle CD20 positivity in the bone marrow of a patient who has a mucosa-associated lymphoid tissue lymphoma should not be regarded as evidence of involvement in the bone marrow.

AIMS: Bone marrow (BM) biopsies of some mucosa-associated lymphoid tissue (MALT) lymphoma patients show scattered or small clusters of CD20+ cells without definite lesions (subtle CD20 positivity). The aim of this study was to evaluate the clinical significance of BM involvement and subtle CD20 positivity in 122 patients diagnosed with MALT lymphoma. METHODS AND RESULTS: Patients were divided into three categories: BM involvement [BM(+)], subtle CD20 positivity, and no BM involvement [BM(-)]. Eleven (9%) showed BM involvement, and 17 (14%) showed subtle CD20 positivity. BM(+) patients had significantly worse progression-free survival (PFS) than BM(-) patients [hazard ratio (HR) 6.25, P = 0.01], but there was no significant difference between subtle CD20 positivity and BM(-) patients. Patients with >30 CD3+ cells among 100 nucleated cells in the areas with increased numbers of CD3+ cells had significantly worse PFS than those with <15 CD3+ cells (HR 5.49, P = 0.02). BM(+) patients with >30 CD3+ cells had worse PFS than those with ≤30 CD3+ cells (P = 0.029), with an extent of BM(+) involvement of >10% positively correlating with >30 CD3+ cells (P = 0.015). CONCLUSIONS: Patients with BM(+) MALT lymphoma showed significantly worse PFS than those with subtle CD20 positivity and BM(-) MALT lymphoma, but the PFS of patients with subtle CD20 positivity MALT lymphoma was not significantly different from that of those with BM(-) MALT lymphoma. Increased numbers of BM T cells in MALT lymphoma patients might be suggestive of a worse prognosis.

A case of bacteremia by Neisseria gonorrhoeae coincident with massive hemorrhage of esophageal varices.

A 42-yr-old man with hepatitis B virus associated liver cirrhosis was admitted to the emergency room because of multiple seizures, a history of chills and myalgia over the previous 2 weeks, and 3 days of melena. He was febrile with a temperature of 38.0°C. There were no symptoms and signs related to the genitourinary system, skin, or joints. Three sets of blood cultures were obtained and oxidase-positive, gram-negative diplococci were detected after 25.9-26.9 hr of incubation in all aerobic vials. The organism was positive for catalase and oxidase, and was identified as Neisseria gonorrhoeae, using a Vitek Neisseria-Haemophilus Identification card (bioMérieux Vitek, Inc., USA). Further, 16S rRNA sequencing of this isolate revealed a 99.9% homology with the published sequence of N. gonorrhoeae strain NCTC 83785 (GenBank Accession No. NR_026079.1). Acute bleeding by variceal rupture seems to be a likely route of introduction of N. gonorrhoeae from the mucosa into the blood. To the best of our knowledge, this is the first case of gonococcal bacteremia in Korea.