High incidence and early onset of nivolumab-induced pneumonitis: four case reports and literature review.

BACKGROUND: Nivolumab, an anti-programmed cell death-1 (PD-1) monoclonal antibody used as an immune checkpoint inhibitor, is commonly employed for its anti-tumor effects against various types of malignant tumors. However, its administration is complicated by immune-related adverse events (irAEs), including pneumonitis. CASE PRESENTATION: We present a case series of four patients with malignant melanoma, non-small cell lung cancer, and hypopharyngeal carcinoma who demonstrated pneumonitis induced by nivolumab, and further review clinicopathological characteristics of these patients in comparison with those of previously reported patients with nivolumab-induced pneumonitis. In our series, 20% of patients who were treated with nivolumab developed pneumonitis, all of which occurred approximately 2 weeks after the initiation of nivolumab treatment. Prompt recognition of the nivolumab-induced pneumonitis allowed for successful resolution. Computed tomography scan images of the patients demonstrated predominantly cryptogenic organizing pneumonia patterns. All patients were males, who had been heavily treated with antitumor drugs prior to nivolumab. CONCLUSIONS: Our case series showed that nivolumab had a high incidence of drug-induced pneumonitis with early onset, supporting the need for renewed attention to nivolumab-induced pneumonitis, particularly in patients with a history of heavy antitumor treatments.

Elevated plasma level of differentiation inhibitory factor nm23-H1 protein correlates with risk factors for myelodysplastic syndrome.

We measured plasma nm23-H1 level (nm23-H1), a differentiation inhibitory factor, by an enzyme-linked immunosorbent assay (ELISA) in patients with aplastic anemia (AA) and myelodysplastic syndrome (MDS). The nm23-H1 in AA was not significantly elevated when compared to normal subjects (6.66 +/- 1.20 ng/ml vs 5.13 +/- 0.81 ng/ml; P = 0.274). In contrast, MDS patients had significantly high levels of nm23-H1 compared not only to normal subjects (11.16 +/- 1.42 vs 5.13 +/- 0.81 ng/ml; P = 0.0004) but also to those of the AA group (11.16 +/- 1.42 ng/ml vs 6.66 +/- 1.20 ng/ml; P = 0.018). In the MDS group of patients, no significant difference was observed in the nm23-H1 levels between patients with refractory anemia (RA) and RA with excess blasts (RAEB)/RAEB in transformation (10.71 +/- 1.61 ng/ml vs 9.24 +/- 2.66 ng/ml; P = 0.672). Of the patients with RA, patients with low risk according to the International Prognostic Scoring System (IPSS) had significantly low levels of nm23-H1 compared to those of IPSS INT-1 level cases (6.40 +/- 1.36 ng/ml vs 13.05 +/- 2.50 ng/ml; P = 0.0028), suggesting that nm23-H1 may be useful as a prognostic marker for MDS, especially in low risk patients.

Chronic lymphocytic leukemia complicated by plasmacytoma originating from different clones.

In a woman with chronic lymphocytic leukemia (CLL), a plasmacytoma developed on the back region after four years. CLL cases complicated with plasmacytoma are rare. In the present case, the plasmacytoma showed kappa cytoplasmic immunoglobulin (Ig), and the CLL showed gamma lambda surface Ig. To reveal the clonal origin of CLL and plasmacytoma, we analyzed Ig gene rearrangements in the patient's peripheral blood and plasmacytoma. Ig gene DNA analysis confirmed the presence of different rearrangements in the heavy and light chain genes of CLL and plasmacytoma. These findings suggest that in this patient, the two B cell malignancies arose from expansion of two phenotypically and genotypically distinct clones.

Refractory anemia with ringed sideroblasts with a low IPSS score progressed rapidly with de novo appearance of multiple karyotypic abnormalities and into acute erythroleukemia (AML-M6A).

We report here a case of refractory anemia with ringed sideroblasts (RARS) with a low risk group by the International Prognostic Scoring System (IPSS) at the time of diagnosis but had a rapid disease progression. Although the patient showed a normal male karyotype at the time of RARS diagnosis, his marrow cells had del(5)(q14) and add(17)(p12) abnormalities 2 months after the diagnosis, and later the marrow cells had multiple abnormalities and the patient expired 6 months after the initial diagnosis of RARS. The patient was diagnosed as having RARS with a low risk group by the IPSS classification, however, one should keep in mind that some patients with myelodysplastic syndromes with low risks by either the French-American-British (FAB) classification or the IPSS classification may have progressive disease and subsequential cytogenetic analysis could predict the disease progression.

Comparative multi-color flow cytometric analysis of cell surface antigens in bone marrow hematopoietic progenitors between refractory anemia and aplastic anemia.

Refractory anemia (RA) in myelodysplastic syndrome (MDS) without prominent dysplasia closely resemble the mild type of aplastic anemia (AA) in their hematological features. This sometimes makes it difficult to distinguish clearly between the two diseases. Using the multi-color flow cytometric technique, we compared cell surface antigen expression patterns on bone marrow hematopoietic progenitor cells which were isolated as a CD34 positive- CD45 dull positive with low side scatter intensity (CD34(+)CD45(dull+)SSC(low)) population in flow cytogram between RA (n=12) and AA (n=11). The antigens analyzed in CD34(+)CD45(dull+)SSC(low) mononuclear cells were: CD38 and CD71 for cell growth-related antigens, CD 33 and CD13 for myeloid and monocytoid lineage-associated antigens, CD7 and CD19 for lymphoid lineage, and CD14 for a monocytic lineage specific antigen. The percentages of CD34(+)CD45(dull+)SSC(low) cells in bone marrow non-erythroid mononuclear cells, and the expression frequencies of CD38, CD71, CD33 and CD13 antigens in CD34(+)CD45(dull+)SSC(low) progenitors were all significantly decreased in AA compared to normal bone marrows (n=7) (P<0.005). In contrast, in RA bone marrows the percentages of CD34(+)CD45(dull+)SSC(low) cells showed wide distribution and the cell surface antigen expression patterns varied among each case: some cases showed low frequencies of CD38 and CD71 expression as well as AA, whereas the others showed high expression frequency of specific antigen(s) which may reflect the clonal expansion of an abnormal clone in bone marrow. An MDS patient who had progressed from RA to RAEB showed further projecting pattern of expression of CD38 and CD33 in CD34(+)CD45(dull+)SSC(low) population in accordance with the disease progression. These data suggest that analysis of cell surface antigen expression patterns of CD34(+)CD45(dull+)SSC(low) progenitor cells by multi-color flow cytometry appears to be a useful method for qualitative and quantitative assessment of marrow progenitor states in AA and RA, therefore this method could be helpful for early detection of clonal evolution in MDS.

Spontaneous reduction of leukemic lymphoma cells possibly by anti-tumor antibody-mediated phagocytosis; a kappa lambda-dual-positive B cell lymphoma.

We have investigated the possible role of anti-tumor antibody detected in a case of follicular lymphoma which demonstrated the spontaneous reduction of leukemic tumor cells. The tumor cells genotypically had monoclonal rearrangements of the immunoglobulin J H and C kappa genes, but phenotypically exhibited surface IgG, A, kappa and lambda (kappa lambda dual positivity). The culture study revealed that IgGlambda, at least, was derived from the serum, and IgAkappa was expressed intrinsically. Furthermore, the positive correlation between the densities of both surface light chains on two-color flow cytometry, the rosette formation study and its inhibition test by the Fcgamma fragment suggested that the serum IgGlambda combined with some antigens on the tumor-cell surface via its Fab portion and with the Fcgamma receptor of macrophages via its Fc portion. From these findings, we regarded the present case as an anti-tumor antibody-coated lymphoma. In addition, the phagocytic study disclosed that the serum-derived IgGlambda, at least, might have induced the phagocytosis of circulating lymphoma cells by macrophages. In conclusion, the existence of the anti-tumor antibody-coated lymphoma may be helpful in clarifying the immunological mechanism of the spontaneous regression occasionally seen in lymphomas.

[Hypereosinophilic syndrome complicated by myelofibrosis].

Hypereosinophilic syndrome (HES) with myelofibrosis was diagnosed in a 36-year-old man on the basis of bone marrow biopsy findings and clinical features. Although the patient was treated with steroid (1 mg/kg), hydroxyurea, and immunosuppressive therapy, eosinophilia persisted. Patients with HES and myelofibrosis are usually unresponsive to antineoplastic agents and/or immunosuppressants. However, cyclosporin may be an effective alternative for such patients.

[A trial for peripheral blood stem cell harvest by combination of G-CSF with ABVD regimen in the management of Hodgkin's disease].

We studied the possibility of performing peripheral blood stem cell (PBSC) harvests during the course of ABVD therapy by adding G-CSF to the treatment regimen. Six patients with high-risk Hodgkin's disease (HD) (5 untreated cases with bulky mass and 1 relapsed case) received G-CSF (5 micrograms/kg) subcutaneously from day 8 to day 13 of their first course of ABVD treatment; the numbers of CD34+ cells and CFU-GM were monitored. PBSC harvests were performed on day 12 and day 13 of subsequent ABVD plus G-CSF treatment courses. For all patients tested, we were able to harvest CFU-GM (3.78 +/- 1.19 x 10(5) colonies/kg) for peripheral blood stem cell transplants (PBSCT) by performing 2 to 4 cycles. of apheresis, without any modification to the original ABVD protocol. These findings suggest that ABVD plus G-CSF therapy is a strong candidate for the treatment of patients with high-risk HD who may undergo autologous PBSCT.

Bone marrow stroma from refractory anemia of myelodysplastic syndrome is defective in its ability to support normal CD34-positive cell proliferation and differentiation in vitro.

We examined the supportive function of stromal cells from patients with refractory anemia (RA) of myelodysplastic syndrome (MDS) on CD34-positive hematopoietic cell proliferation and differentiation using a long-term bone marrow culture (LTMC) system. Primary marrow stromal cells were obtained from 11 MDS RA patients and 12 healthy volunteers, and freshly prepared CD34-positive bone marrow cells from a normal subject were inoculated onto the stroma. There seems to be three broad patterns of hematopoietic cell growth in the LTMCs. In one group, hematopoietic cells were maintained at near normal levels (type A). In the second group, the number of hematopoietic cells increased within the first 5-10 days of culture, but declined to low levels at 15-20 days of culture as compared with normal control (type B). In the third group, the incidence of hematopoietic cells steadily declined from the beginning of the culture (type C). Furthermore, apoptotic change of hematopoietic cells was very frequently observed in cultures with the type C stroma, which were especially defective for supporting CD34 + cell proliferation and differentiation. The expression of CD95 on hematopoietic cells was induced by the type C stroma, however, production of fas ligand by the stromal cells was not observed. These findings suggest a lack of hematopoietic supportive function in some cases of MDS RA and also indicate that there is heterogeneity of stromal function among MDS RA patients.

Stimulatory effects of substance P on CD34 positive cell proliferation and differentiation in vitro are mediated by the modulation of stromal cell function.

Substance P (SP) is a neuropeptide widely distributed in the nervous system. Extensive study has shown SP stimulates production of various cytokines by bone marrow stromal cells, although, the role of SP in hematopoietic phenomena is still unclear. Recently, we established a human cloned stromal cell line, HAS303, which can support hematopoietic stem cell proliferation and differentiation in vitro. We used this culture system to examine the effects of SP. Expression of the mRNAs of neurokinin (NK)-1R, NK-2R and NK-3R, specific SP receptors, on HAS303 cells was demonstrated by the RT-PCR. CD34+ cells isolated from bone marrow were co-cultivated with HAS303 cells in the presence and absence of SP and the total hematopoietic cells and progenitors were counted every 5 days. Introducing SP (10(-8) M) to the co-cultures significantly increased the number of total cells and progenitors compared with control cultures. SP showed no enhancing activity on CD34+ cells cultured alone. SP also stimulated IL-3-dependent colony formation of whole bone marrow MNCs in a soft agar culture system, but showed no such activity on isolated CD34+ cells in this system. These observations suggest that SP stimulated HAS303 cells, activated HAS303 cells, and stimulated the proliferation and differentiation of CD34+ cells. Treating HAS303 cells with SP increased the intracellular Ca2+ concentration and stimulated production of G-CSF, GM-CSF, SCF and IL-6, but not IL-1alpha, IL-1beta and TNF-alpha, but did not enhance proliferation. All these findings suggest that SP mediates hematopoietic cell proliferation and differentiation in vitro by activating stromal cell function.

Vitamin K2 selectively induces apoptosis of blastic cells in myelodysplastic syndrome: flow cytometric detection of apoptotic cells using APO2.7 monoclonal antibody.

We have previously reported that vitamin K2 (VK2) but not VK1 has a potent apoptosis-inducing effect on freshly isolated leukemia cells from patients with various types of leukemia. By multi-color flow cytometric analysis using monoclonal antibody (mAb), APO2.7, which detects mitochondrial 7A6 antigen specifically expressed by cells undergoing apoptosis, we further investigated the apoptosis-inducing effect of VK2 on minor populations of leukemic blast cells in bone marrow from patients with myelodysplastic syndrome (MDS) and overt myeloid leukemia (post-MDS AML). Limiting dilution of CD95 (anti-Fas) mAb-treated apoptotic Jurkat cells with nonapoptotic CTB-1 cells revealed that APO2.7-positive Jurkat cells were consistently detectable by flow cytometry when present at levels of at least 5% in the CTB-1 suspension. In patient samples the gating area for leukemic clone was determined using cell surface antigen-specific mAbs conjugated with either fluorescein isothionate (FITC) or phycoerythrin (PE) and subsequently the cells stained with phycoerythrin cyanine (PE-Cy5)-conjugated APO2.7 mAb were assessed within the gating area of the leukemic clone for monitoring apoptosis. Treatment of the bone marrow mononuclear cells with 3-10 microM of VK2 (menaquinone-3, -4 and -5) in vitro potently induced apoptosis of the leukemic blast cells as compared with the untreated control cells in all 15 MDS patients tested. This effect was more prominent on blastic cells than that on mature myeloid cells such as CD34-/CD33+ gated cells. In addition, VK2 performed much less effectively on CD3-positive lymphoid cells. In contrast to VK2, VK1 did not show apoptosis-inducing activity. These data suggest that VK2 may be used for treatment of patients with MDS in blastic transformation.

A sole del(15q) anomaly in post-myelodysplasia acute myeloid leukemia.

We report the second case of post-myelodysplasia acute myeloid leukemia (post-MDS AML) with a sole chromosome change del(15q). This anomaly is rarely seen. To our knowledge, only seven cases so far have been reported in human neoplasias, including one case each of acute myeloid leukemia (AML), acute lymphoid leukemia, post myelodysplasia AML, myelodysplastic syndrome, myelofibrosis, macroglobulinemia, Hodgkin's lymphoma and uterine leiomyoma. This case suggests that del(15q) is related to lympho-myeloproliferative disorders. Moreover, we speculate that certain oncogene(s) located on 15q might have some role in the progression of the disease, since the del(15q) anomaly appeared only in the AML phase in this case.

[Possible role of immunocompetent cells on periodic exacerbation of idiopathic thrombocytopenic purpura].

A 44 year-old man was admitted to our hospital in October, 1992 with epistaxis. Fifteen months before admission, thrombocytopenia had been pointed out, but he had no bleeding episode. At admission, neither hepatosplenomegaly nor lymph node swelling was observed. Hematological findings were as follows; WBC 10,000/microliter, Hb 14.0 g/dl, PLT 5,000/microliter, including giant platelets. Platelet associated IgG (PAIgG) was 471 ng/10(7) cells. Bone marrow aspiration revealed normocellularity with moderate increase in the number of mature megakaryocytes, but no dysplastic changes were seen. Biochemical and radiological examinations disclosed neither malignant diseases nor autoimmune diseases. Based on the diagnosis of idiopathic thrombocytopenic purpura, danazol therapy (300 mg/day) was started in November, 1992. After initiation of treatment, the platelet count changed cyclically every 4 weeks. To elecuidate the mechanism of this phenomenon, we periodically evaluated the patient's immunological background. T lymphocyte counts and subset proportions remained almost the same through out the course, whereas NK cell counts and NK activity coincided with the change of the platelet count. These results suggest that in this case NK cells may play a role in the cyclic fluctuation of platelet count by regulating the immune system.

Possible involvement of bone marrow stromal cells in agranulocytosis caused by vesnarinone treatment.

Vesnarinone, an oral therapeutic agent for cardiac failure, causes agranulocytosis as a side effect. To elucidate the mechanism of occurrence of the agranulocytosis, we examined the effect of vesnarinone on granulopoiesis using an in vitro human long-term bone marrow culture system. Addition of vesnarinone to the culture decreased the total number of hematopoietic cells, mainly composed of mature granulocytes and macrophages, but increased the number of granulocyte-macrophage progenitor cells (CFU-GM) and CD33-CD34+ cells as compared with an untreated control. Differentiation of CFU-GM was induced by removing the agent from the culture medium, indicating that the effect of vesnarinone was reversible. The agent did not directly affect CFU-GM in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF). Furthermore, treatment of stromal cells with vesnarinone repressed the production of G, GM, M-CSF, suggesting that the agent may cause a hematopoietic disorder, agranulocytosis, through the impairment of stromal cell function.

Establishment of a novel B-lymphoma cell line, CTB-1, with strong Pas antigen expression having chromosomal translocation (14;22).

We established a new lymphoma cell line, designated CTB-1, from pericardial effusion of a patient with diffuse large B-cell lymphoma. This cell line showing vigorous growth ability has undergone 260 passages over a period of 34 months in suspension culture, and is heterotransplantable to nude mice. The cultured cells were positive for CD10, CD19, CD20, CD21, HLA-DR, and surface IgG kappa, and negative for T cell antigens. Chromosomal analysis revealed a t(14;22)(q32;q11) that is consistent with original lymphoma cells. CTB-1 cells show the high cell surface expression level of Fas antigen/APO-1. However, ligation of Fas antigen with anti-Fas monoclonal antibody (clone CH-11) did not induce apoptosis of CTB-1 cells. This suggests that Fas itself or the downstream signaling pathways of Fas may be impaired in this cell line. This new cell line may provide a useful in vitro system to study the biology and pathogenesis of B-cell lymphoma which is independent of Fas-mediated apoptosis.

[A lower-leg ulcer during hydroxyurea therapy for essential thrombocythemia].

A skin ulcer of the lateral malleous developed in a 61-year-old man receiving hydroxyurea for essential thrombocythemia. In the past, skin ulcers have been reported in patients with chronic myeloproliferative diseases, including essential thrombocythemia, who had been treated with hydroxyurea. In the current case, vasculitis or thrombi in vessels of the biopsied specimen of the lower leg were not observed, and the patient required skin-graft operation. Accordingly, we concluded that the skin ulcer might be due to the administration of hydroxyurea. Thus, the dose of hydroxyurea was decreased.

Analysis of bone marrow and peripheral blood immunoregulatory lymphocytes in patients with myelodysplastic syndrome.

The cell surface phenotype of immunoregulatory lymphocytes in bone marrow (BM) and peripheral blood (PB) in myelodysplastic syndrome (MDS), a stem cell disorder, was analyzed. Mononuclear cells from 25 patients with refractory anemia (RA) and nine with RA with an excess of blasts (RAEB) were characterized by two-color flow cytometry using various monoclonal antibodies. No significant change of CD3+, CD4+, and CD8+ cells in PB, but a decrease of the percent of positive cells for CD8++ among the total lymphocyte (%CD8++) was noticed in RA patients. On the other hand, in BM of RA patients, a decrease in the number of CD4+ cells, but not CD8++ cells, was noted. In RAEB patients, the absolute numbers of CD3+, CD4+, CD8+, and CD8++ cells in BM were decreased; however, the ratio of these lymphocytes was not changed. No change was observed among the CD4+ subsets in PB of RA or RAEB patients. In BM, a decrease in percentage of CD4+CD45RA+ (%CD4+CD45RA+; naive cell) and increases in CD4+CD45RO+ (%CD4+CD45RO+; memory cell) and CD4+CD29+ (%CD4+CD29+; helper/inducer) among CD4+ cells were found in both RA and RAEB patients. Analysis of the CD8++ subset showed an increased number of CD8++CD11a+ cells (activated CTL) in both BM and PB of RA patients, but not of RAEB patients. Furthermore, increments in CD56+ and CD16+ cells among CD3- cells (natural killer; NK cells) were seen in RA patients but not in RAEB patients. It remains unclear whether lymphocytes in MDS patients were involved in the abnormal (MDS) clones, but our results regarding the increments of CD8++CD11a+ and NK cells in RA patients suggest that the mechanism of immune surveillance against the abnormal MDS clones was activated in these RA patients, but not in RAEB patients. Further investigation is required to clarify the functions of these immunoregulatory lymphocytes in MDS patients.

Cytotoxic lymphocytes in the peripheral blood of patients with B cell lymphomas.

In order to analyze systemic immune surveillance in patients with B cell non-Hodgkin's lymphomas (B-NHL), we investigated circulating lymphocytes using two-color flow cytometry. The proportions of CD3-CD56+ natural killer (NK) cells and CD8++(bright) S6F1++ killer-effector T cells corresponding to activated cytotoxic T lymphocytes (aCTL) were studied in the peripheral blood of 26 patients with indolent lymphoma (IL) and 24 with aggressive lymphoma (AL). The AL patients with both limited disease and advanced disease had an increased proportion of NK cells. However, this feature was not evident in IL patients with either limited or advanced disease. In contrast, an increased proportion of aCTL was observed only in IL patients with advanced disease. These findings indicate that IL may differ from AL in terms of immune surveillance against neoplastic B cells.