Increase in the frequency of community-acquired methicillin-resistant Staphylococcus aureus clones among inpatients of acute care hospitals in the Kyoto and Shiga regions, Japan.

BACKGROUND: Specific epidemic clones of hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) are responsible for the worldwide spread of MRSA. However, in recent years, the isolation of community-acquired MRSA (CA-MRSA) clones has been increasing. We investigated the latest molecular epidemiology trends of HA-MRSA and CA-MRSA clones in the Kyoto and Shiga regions, Japan. MATERIALS AND METHODS: All nonduplicate MRSA isolates obtained from the clinical specimens of inpatients at four acute care hospitals in the Kyoto and Shiga regions between 2014 and 2019 were typed using the PCR-based open reading frame typing (POT) method. CA-MRSA and HA-MRSA were classified according to the POT1 values. We performed whole-genome sequencing analysis for representative isolates displaying common POT types. RESULTS: A total of 2413 isolates were included in the study, comprising 1730 nosocomial and 683 nonnosocomial isolates. The rates of HA-MRSA decreased from 50.2% in 2014 to 19.0% in 2019, while those of CA-MRSA increased from 44.7% to 76.4% (p < 0.001). Isolates belonging to the most common 10 POT types (CA-MRSA, n = 6; HA-MRSA, n = 4) accounted for 42% of the isolates studied and were obtained from 3 or more hospitals. Whole-genome sequencing analysis showed that the common CA-MRSA isolates with POT types 106-137-80, 106-9-80, 106-9-2, and 106-137-2, those with POT types 106-183-37 and 106-129-5, and HA-MRSA isolates with POT types 93-191-103, 93-157-127, 93-137-103, and 93-223-111 belonged to ST8-SCCmecIV, ST1-SCCmecIV, and ST764-SCCmecII, respectively. CONCLUSION: A recent clonal shift from HA-MRSA to CA-MRSA occurred, and specific regional clones were prevalent among inpatients in the Kyoto and Shiga regions.

The clinical significance of PNH-phenotype cells accounting for < 0.01% of total granulocytes detected by the Clinical and Laboratory Standards Institute methods in patients with bone marrow failure.

Small populations of glycosylphosphatidylinositol-anchored protein-deficient (GPI[-]) cells accounting for up to 0.01% of total granulocytes can be accurately detected by a high-sensitivity flow cytometry (FCM) assay established by the Clinical and Laboratory Standards Institute (CLSI method) and have a prognostic value in bone marrow failure (BMF); however, the significance of GPI(-) granulocytes accounting for 0.001-0.009% of granulocytes remains unclear. To clarify this issue, we examined the peripheral blood of 21 BMF patients in whom minor (around 0.01%) populations of GPI(-) granulocytes had been previously detected by a different high-resolution FCM method (OPTIMA method, which defines ≥ 0.003% GPI(-) granulocytes as an abnormal increase) using both the CLSI and OPTIMA methods simultaneously. These two methods detected an "abnormal increase" in GPI(-) granulocytes in 10 patients (48%) and 17 patients (81%), respectively. CLSI detected 0.002-0.005% (median, 0.004%) GPI(-) granulocytes in 7 patients who were deemed positive for PNH-type cells according to the OPTIMA method, which detected 0.003-0.012% (median 0.006%) GPI(-) granulocytes. The clone sizes of GPI(-) cells detected by each assay were positively correlated (r = 0.994, p < 0.001). Of the seven patients who were judged positive for PNH-type cells by OPTIMA alone, five received immunosuppressive therapy, and all of them achieved a partial or complete response. GPI(-) granulocytes detected in BMF patients by the CLSI method should thus be considered significant, even at percentages of < 0.01%.

[Case Conference of Hematological Malignancies Based on the Morphology of Blood Cells: Chairmen's Introductory Remarks].

A case conference of hematological malignancies based on the morphology of blood cells was held as a Joint Symposium of the Japanese Society of Laboratory Medicine and Japanese Society of Laboratory Hematology. This style of joint symposium was held four times from 2012 to 2016, whereas child cases were presented for the first time this year. The 4 cases presented in this symposium were as follows: an infant with Down syn- drome showing an atypical clinical course of transient abnormal myelopoiesis (TAM) and myeloid leukemia, a relatively older girl with juvenile myelomonocytic leukemia (JMML), one adult with acute myeloid leukemia (AML) with inv (16) (p13.1q22); CBFB-MYH11 morphologically resembling AML with t (8;21) (q22;q22.1); RUNX1-RUNX1T1, and one adult with high-grade B-cell lymphoma showing t (14;18) (q32;q21); IGH/BCL2. Each case included pathological and interesting morphological findings that were carefully examined and in- tensively discussed by two experienced commentators and participants, including pediatric hemato- pathologists. The importance of the morphological evaluation of characteristic cells such as immature leukemic blasts or lymphomatous ones was reconfirmed at this conference. In addition, immunological, cytogenetic, and molecular examinations were also essential for the final diagnosis of these cases. [Review].

[Industry-Academia Collaboration in the Clinical Laboratory Field: Chairmen's Introductory Remarks].

Industry-academia collaboration has become essential in contemporary medicine. Therefore, many institutes including university corporations have promoted the establishment of an endowed chair and/or performed collaborative research. This symposium was held to overview the present status of industry-academia collaboration in the clinical laboratory field. As a representative of the industry, Mr. Taniguchi (Sysmex) presented the development process of M2BP Glycosylation Isomer, a new marker for liver fibrosis. Mr. Saitoh (Horiba) introduced the achievements of joint collaborative research with Kyoto Prefectural University of Medicine, especially the practical realization of an automated hematology analyzer capable of simultaneously measuring C-reactive protein. Mr. Setoyama (LSI Medience) presented on the characteristic collaboration between academia and commercial laboratories such as Tsukuba Medical Laboratory of Education and Research (TMER). On the other hand, as a representative of academia, Associate Prof. Imai (Kyoto Prefectural University of Medicine) summarized the necessity of clinical laboratories spread regenerative medicine. Finally, Prof. Koshiba (Hyogo College of Medicine) presented on the industry-academia collaboration in routine laboratory work in his institute.

The relationship of fibroblast growth factors 21 and 23 and α-Klotho with platelet activity measured by platelet volume indices.

BACKGROUND: Subjects with high fibroblast growth factor 21(FGF21) and 23 (FGF23), endocrine hormones that regulate insulin sensitivity and phosphate metabolism, respectively, are reported to have a higher risk for adverse cardiovascular outcome. Therefore, the relationship of FGF21, FGF23, and α-Klotho (co-receptor for FGF23 signaling) with mean platelet volume (MPV) and platelet distribution width (PDW), two platelet volume indices that reflect platelet activity, was investigated. METHODS: Data from 156 patients admitted to the cardiology department were analyzed. MPV and PDW were measured by an automatic blood counter, and serum FGF21, FGF23, and α-Klotho concentrations were measured by an enzyme-linked immunoassay. RESULTS: Log(FGF21) was significantly correlated with serum triglycerides but did not differ according to the use of non-use of antidiabetic or lipid-lowering drugs. MPV and PDW were significantly correlated (R=0.475, p<0.001). MPV was significantly correlated with log(FGF21) (R=-0.167, p<0.05) and log(FGF23) (R=0.351, p<0.001) but not with log(α-Klotho). Linear regression analysis showed a negative and positive association of log(FGF21) and log(FGF23), respectively, with MPV that was independent of possible confounders including sex, age, renal function, and antithrombotic drug use. In addition, log(FGF23) was found to have a significant independent positive association with PDW. CONCLUSIONS: Among cardiac patients, FGF21 had a negative association with MPV, whereas FGF23 had a positive association. Future studies of serum FGF23/FGF21 concentrations and the incidence of thromboembolic disorders are warranted.

Platelet volume indices are associated with systolic and diastolic cardiac dysfunction, and left ventricular hypertrophy.

BACKGROUND: Mean platelet volume (MPV) and platelet distribution width (PDW) are indices that reflect platelet activity. We investigated the association between these platelet indices and left ventricular hypertrophy and cardiac function. METHODS: We analyzed the data of 1241 patients who were admitted to the Cardiology Department. RESULTS: Both MPV and PDW were selected as independent factors associated with left ventricular systolic and diastolic dysfunction, and left ventricular hypertrophy. The highest tertile of MPV and PDW was associated with left ventricular systolic dysfunction (left ventricular ejection fraction of <50 %) with an odds ratio of 1.53 and 2.03, respectively, when the respective lowest tertile was used as reference. The highest PDW tertile was associated with left ventricular hypertrophy with an odds ratio of 1.56 (95 % CI, 1.13-2.15) and with dysfunction with an odds ratio of 3.34 (95 % CI, 1.54-7.25). CONCLUSIONS: Indices of platelet activation (MPV and/or PDW) were independently associated positively with left ventricular hypertrophy and left ventricular systolic and diastolic dysfunction. Whether these platelet indices represent useful markers for identifying individuals at higher risk for thromboembolic disease and organ damage among cardiac patients awaits further investigation.

Acute monoblastic leukemia that switched lineage at relapse to acute lymphoblastic leukemia: a case report.

We herein present the case of an acute monoblastic leukemia infant who relapsed with acute lymphoblastic leukemia (ALL). Complete remission was achieved after an acute myeloblastic leukemia-directed chemotherapy, but the patient relapsed with pro-B ALL. As he did not respond to acute myeloblastic leukemia-type reinduction therapy, he was switched to ALL-type chemotherapy, and a complete remission was achieved. Unrelated cord blood stem cell transplantation was performed, but he relapsed with pro-B ALL again. After he received ALL-type chemotherapy, he underwent another bone marrow transplant from his human leukocyte antigen mismatch mother, and has been free from recurrence for over 8 months.

Interferon-ß1b increases Th2 response in neuromyelitis optica.

A Japanese randomized controlled study showed that Interferon â (IFN-â1b) therapy is clinically effective in decreasing the frequency of attacks in multiple sclerosis (MS), even in optico-spinal MS (OSMS). However, recent studies have shown that IFN-â (IFN-â1a/IFN-â1b) treatment was not effective in neuromyelitis optica (NMO) patients and that the diminished benefit of IFN-â treatment in NMO may be due to different immune responses to IFN-â. We determined longitudinally the expression of CCR5, CXCR3 and CCR4 on CD4+ T and CD8+ T cells in the blood from patients with NMO and MS treated with IFN-â1b. During a 12-month period of IFN-â1b therapy, the annualized relapse rate decreased in MS patients but not in NMO patients. There was no significant difference in the expression of the chemokine receptors between NMO and MS at baseline. The percentages of CD4+CCR5+ and CD4+CXCR3+ T cells, representative of the Th1 response, were decreased in both NMO and MS after treatment. The percentage of CD4+CCR4+ T cells, representative of the Th2 response, was decreased in MS, but those for NMO was significantly increased compared with the pretreatment levels. Our results indicate that IFN-â1b-induced up-modulation of the Th2 response in NMO patients may be the source of differences in the therapeutic response to IFN-â1b therapy. In the present study, Th2 predominance is involved in the pathogenesis of NMO.

[Acquisition of accreditation ISO 15189 and view of the future--case of a private college].

We received ISO 15189 accreditation (International Organization for Standardization 15189) in 2009. Several effects from the subjective points are shown below, 1. The reliability of the test results has improved. 2. Skill or knowledge level of staff has improved. 3. Internal recognition has improved. 4. Procedures to prevent accidents have been enforced. 5. Management system has improved. 6. Effective management tool for the manager. In addition to high costs for qualification and maintenance, extensive human resources are required to prepare documents. We need to make further efforts to aim at better cost-effectiveness.

Effectiveness of COVID-19 vaccination in healthcare workers in Shiga Prefecture, Japan.

This study, which included serological and cellular immunity tests, evaluated whether coronavirus disease 2019 (COVID-19) vaccination adequately protected healthcare workers (HCWs) from COVID-19. Serological investigations were conducted among 1600 HCWs (mean ± standard deviation, 7.4 ± 1.4 months after the last COVID-19 vaccination). Anti-SARS-CoV-2 antibodies N-Ig, Spike-Ig (Roche), N-IgG, Spike-IgM, and -IgG (Abbott), were evaluated using a questionnaire of health condition. 161 HCWs were analyzed for cellular immunity using T-SPOT® SARS-CoV-2 kit before, and 52 HCWs were followed up until 138.3 ± 15.7 days after their third vaccination. Spike-IgG value was 954.4 ± 2282.6 AU/mL. Forty-nine of the 1600 HCWs (3.06%) had pre-existing SARS-CoV-2 infection. None of the infectious seropositive HCWs required hospitalization. T-SPOT value was 85.0 ± 84.2 SFU/106 cells before the third vaccination, which increased to 219.4 ± 230.4 SFU/106 cells immediately after, but attenuated later (to 111.1 ± 133.6 SFU/106 cells). Poor counts (< 40 SFU/106 cells) were present in 34.8% and 38.5% of HCWs before and after the third vaccination, respectively. Our findings provide insights into humoral and cellular immune responses to repeated COVID-19 vaccinations. COVID-19 vaccination was effective in protecting HCWs from serious illness during the original Wuhan-1, Alpha, Delta and also ongoing Omicron-predominance periods. However, repeated vaccinations using current vaccine versions may not induce sufficient cellular immunity in all HCWs.

Incremental value of early systolic lengthening and postsystolic shortening in detecting left anterior descending artery stenosis using nonstress speckle-tracking echocardiography.

The diagnosis of coronary artery disease (CAD) with nonstress echocardiography remains challenging. Although the assessment of either early systolic lengthening (ESL) or postsystolic shortening (PSS) allows the sensitive detection of CAD, it is unclear whether the integrated analysis of ESL and PSS in addition to the peak systolic strain can improve the diagnostic accuracy. We investigated the incremental value of ESL and PSS in detecting left anterior descending artery (LAD) stenosis using nonstress speckle-tracking echocardiography. Fifty-nine patients with significant LAD stenosis but without visual wall motion abnormalities on echocardiography at rest (30 single-vessel stenosis, 29 multivessel stenosis) and 43 patients without significant stenosis of any vessel were enrolled. The peak systolic strain, the time to ESL (TESL), and the time to PSS (TPSS) were analyzed in all LAD segments, and the incremental values of the TESL and TPSS in detecting LAD stenosis and the diagnostic accuracy were evaluated. In the apical anterior segment, the peak systolic strain was significantly lower and TESL and TPSS were significantly longer in the single-vessel group than in the no stenosis group. In the single-vessel group, the addition of TESL and TPSS to the peak systolic strain significantly increased the model power in detecting stenosis, and the integrated analysis improved diagnostic accuracy compared with the peak systolic strain alone. In contrast, this incremental value was not demonstrated in the multivessel group. The integrated analysis of the peak systolic strain, ESL, and PSS may allow better screening of single-vessel LAD stenosis using nonstress speckle-tracking echocardiography.

Flow cytometric immunophenotyping of peripheral T cell neoplasms using CD3 gating.

Peripheral T cell neoplasms (PTCNs) such as peripheral T cell lymphoma, adult T cell leukemia/lymphoma, and mycosis fungoides are associated with poorer prognoses compared to B cell neoplasms. Hence, an accurate and early diagnosis is necessary for the successful treatment of PTCNs; however, this can be difficult to achieve. In this study, flow cytometric immunophenotyping using CD3 gating was performed retrospectively on 56 samples from 52 patients diagnosed with PTCNs, and the analytical data were compared with the immunohistochemical findings. Abnormal CD3 T cell populations were distinguishable from the normal T cell population, using this CD3 gating strategy.

Mean platelet component and mean platelet volume as useful screening markers for myelodysplastic syndrome.

BACKGROUND: Hematologic disorders, including myelodysplastic syndrome (MDS), are difficult to identify in routine hematologic examinations using automated hematology analyzers. However, the practical uses of mean platelet component and mean platelet volume (MPV) measured by these analyzers as screening markers for MDS, remain unclear. METHODS: Mean platelet component and MPV values were measured in the peripheral blood of patients with MDS, aplastic anemia, idiopathic thrombocytopenic purpura, myeloproliferative neoplasms, and in healthy controls using an automated hematologic analyzer. Cutoff values for discriminating between the MDS group and healthy controls were determined by recursive partitioning analysis. RESULTS: Mean platelet component was significantly lower in MDS patients compared with controls, while MPV was significantly higher. Combined cutoff values for MDS diagnosis of <25.3 g/dL for mean platelet component and >10.0 fL for MPV showed a specificity and positive predictive value of 99.9% and 99.1%, respectively. These cutoff values also differentiated between MDS and diagnoses of aplastic anemia, idiopathic thrombocytopenic purpura, and myeloproliferative neoplasms. CONCLUSION: Mean platelet component and MPV may, thus, be useful and convenient screening markers for MDS.

False Prolongation of Prothrombin Time in the Presence of a High Blood Concentration of Daptomycin.

Prothrombin time (PT) can reportedly be falsely prolonged by the antimicrobial drug daptomycin (DAP), and concomitant use of phosphatidylglycerol (PG). Although high doses of DAP (>6 mg/kg/day) are recommended for severe infection and result in a high blood concentration, the extent to which high blood concentrations of DAP interfere with PT, in the presence or absence of PG, has yet to be determined when using the HemosIL RecombiPlasTin 2G (Werfen Japan, Tokyo, Japan). We examined the effects of high doses of DAP on PT using this reagent. DAP (0-500 mg/L) was added to normal plasma and plasma with an already prolonged PT in the presence or absence of liposomal amphotericin B (L-AMB, 5-50 mg/L) or COATSOME EL-01 empty cationic liposomes (CS, 25-250 mg/L). Furthermore, we undertook a Monte Carlo simulation to calculate the probability of achieving DAP concentrations >100, >200 and >500 mg/L 0-48 hr after administering 6-12 mg/kg of DAP. Apparent PT increased with increasing DAP concentration, but neither L-AMB nor CS appeared to further elevate PT when co-administered with DAP. The probability of achieving DAP concentrations >100 and >200 mg/L increased with DAP dose. Higher doses of DAP than the approved dose caused false prolongation of PT. PT should be monitored carefully in patients taking high doses of DAP; ideally, PT should be measured at the trough blood concentration of DAP. Concomitant use of L-AMB and CS did not generally further elevate PT when co-administered with DAP.

Flow cytometric immunophenotyping of adult T-cell leukemia/lymphoma using CD3 gating.

Adult T-cell leukemia/lymphoma (ATLL) is a lymphoproliferative neoplasm of helper T lymphocytes caused by human T-cell leukemia virus type-1 (HTLV-1). The disease was first described in Kyushu, in southwestern Japan, and most frequently occurs in endemic areas, such as Japan, the Caribbean basin, West Africa, Brazil, and northern Iran. ATLL is essentially a disease of adults, characterized clinically by generalized lymphadenopathy, hepatosplenomegaly, skin lesions, and hypercalcemia. The prognosis of most patients is quite poor, with a median survival time of only 13 months, even if multiagent combination chemotherapy is given. In the present study, flow cytometric immunophenotyping with CD3 gating was performed on 30 samples from 26 patients who had been given a diagnosis of ATLL. The records of these patients also were reviewed retrospectively. In 14 of the 30 samples, an abnormal CD3(low) T-cell population was distinguishable from the normal T-cell populations by flow cytometric analysis. Herein we report a novel strategy for flow cytometric immunophenotyping of ATLL facilitated by CD3(low) gating.

Decreased CD14+CCR2+ monocytes in active multiple sclerosis.

The expression of CCR2, a receptor to MCP-1, on blood monocytes was measured in 15 patients with active multiple sclerosis (MS). We determined the ratio of CD4+CXCR3+cells (Th1), CD4+CCR4+cells (Th2), and CD14+CCR2+ cells using 3-color flow cytometry. The CD4+CXCR3+/CD4+CCR4+ ratio, which represents the Th1/Th2 balance, was significantly elevated in the active MS patients compared to the healthy controls. The expression of CCR2 and CD14 on the monocytes in the MS patients was markedly decreased. There was a significant negative correlation between the Th1/Th2 ratio and the CCR2 and CD14 expression on monocytes. In the pathogenesis of MS, the CD14+CCR2+ blood monocytes may play an important role in the shift from active MS to a state in which the disease is in remission.

Genomic heterogeneity of type II CD36 deficiency.

BACKGROUND: CD36 deficiency has been classified in two types, i.e., type I and type II CD36 deficiency. Possible pathological involvement of CD36 deficiency has been suggested in humans, but is still confounding. Homozygous or compound heterozygous mutations (CD36(-/-)) were demonstrated in type I CD36 deficiency, while the genomic or molecular background of type II CD36 deficiency is still unclear, which may bring confounding interpretations of the cause-and-effect events in human CD36 deficiency. In this study, we analyzed the genotype and frequency of type II CD36 deficiency in Japanese populations, and its hereditary pattern in three families. METHODS: Genotypes and protein expression levels of CD36 were examined in 238 Japanese subjects. Genotype was analyzed in the coding region of the CD36 gene. The expression level of CD36 protein was analyzed by flow cytometry after staining with monoclonal anti-CD36 antibody and assessed as mean fluorescence intensity (MFI). RESULTS: Among 238 subjects, subjects for wild-type gene (WT), a single mutation (CD36(+/-)), and CD36(-/-) were 141, 44 and 53, respectively. Monocyte MFI (mean+/-SD) in subjects for WT, CD36(+/-), and CD36(-/-) were 35.7+/-8.5, 15.2+/-3.4, and 0.4+/-0.3, respectively (P<0.0001, between groups). Those of platelets in subjects for WT, CD36(+/-), and CD36(-/-) were 27.1+/-10.6, 11.5+/-6.3, and 0.5+/-0.3, respectively (P<0.0001, between groups). Subjects of both WT and CD36(+/-) were observed in type II CD36 deficiency. Monocyte and platelet MFI in family members of type II CD36 deficiency and 218 unrelated Japanese suggested that the expression level of CD36 protein in monocytes was directly dependent on genotypes. On the other hand, those in platelets were affected by additional heritable factor(s) in addition to the coding region genotype. CONCLUSIONS: MFI in monocytes showed a strong gene-dosage-dependency. On the other hand, MFI in platelets was affected by heritable factor(s) in addition to the coding region genotype, which resulted in heterogeneity of type II CD36 deficiency.

[Acquired inhibitor against coagulation factor V with severe hematuria].

A 42-year-old man was admitted with hematuria after a common cold. No purpura could be observed but there was oozing on the site of the forearm where blood had been taken in a previous hospital. Platelet count was 292 x 10(3)/microliter, examination of coagulation system showed abnormalities; prolonged prothrombin time: PT (99.7 sec) and activated partial thromboplastin time: APTT (more than 200 sec), which suggested deficiency of coagulation factor II (FII), factor V (FV) or factor X (FX). In fact, the FV activity was only 2% of the pooled normal plasma. Mixing test of patient's plasma with normal pooled plasma revealed the existence of an FV inhibitor (FVI), which was IgA with an activity levels of 3 Bethesda unit/ml. Although hematuria stopped soon after beginning treatment with steroids (PSL), the abnormalities in PT and APTT improved very slowly and incompletely. At the time of writing, FVI is still observed ten months after onset. The patient had no underlying disease, and in this case FVI appeared following a common cold. Previous reports have said that FVI can cause mild bleeding, and it disappear in a short time. This case showed the possibility of the hidden presence of FVI in patients with hematuria.

An approach for diagnosing plasma cell myeloma by three-color flow cytometry based on kappa/lambda ratios of CD38-gated CD138(+) cells.

BACKGROUND: World Health Organization (WHO) criteria are commonly used to diagnose plasma cell myeloma (PCM); however, these criteria are complex and require several laboratory parameters. For differentiating reactive plasmacytosis from clonal plasma cell (PC) neoplasms such as PCM, it is important to accurately determine the expression of cytoplasmic immunoglobulin light chains. METHODS: We retrospectively analyzed the records of 27 selected patients with PCM who underwent bone biopsies for confirmative diagnosis according to WHO criteria. Twenty-three controls were also investigated. In the present study, all the samples were analyzed using flow cytometry (FC) in the side scatter vs. CD38 histogram mode, and the CD38-gated PC population was identified. Bivariate histograms of CD138/kappa and CD138/lambda were assessed, and the ratios of dual-positive cells to the CD138(+) PC population were calculated. The kappa/lambda ratio was defined as the ratio of CD138/kappa to CD138/lambda. RESULTS: PCM cells were distinguished from normal PCs using cutoff levels between 0.76 and 1.5, at a sensitivity of 96.3% and specificity of 95.7%. CONCLUSIONS: Three-color FC analysis is simple to perform and inexpensive, with clinically relevant data obtained soon after the completion of FC measurements. The detection of the cytoplasmic kappa/lambda ratio of CD38-gated CD138(+) PCs may be a useful tool in the diagnosis of PCM. To the best of our knowledge, this report represents the first diagnostic assessment of the cytoplasmic kappa/lambda ratio in CD38-gated CD138+ PCs using FC analysis. This method may help in more simple, efficient, rapid, and accurate diagnosis of PCM. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1568085959771735.