Langerhans Cell Histiocytosis With Unusual Hexagonal Crystals in Addition to Usual Charcot-Leyden Crystals. Report of a Patient With Possible Process of Crystal Formation and Clinical Significance of a "Necrotic" Change.

Langerhans cell histiocytosis is a rare neoplastic disorder characterized by the proliferation of Langerhans cells and often accompanied by eosinophil infiltration. Charcot-Leyden crystals, composed of galectin 10, are occasionally observed in Langerhans cell histiocytosis; however, histological images are rarely reported. We herein present a patient with Langerhans cell histiocytosis with Charcot-Leyden crystals and hexagonal crystals by describing the histologic and immunohistochemical features of a lymph node. A unique distribution of Charcot-Leyden crystals and hexagonal crystals was observed in this patient, shedding light on their possible formation process of the latter. We discuss the biological significance of eosinophilic abscesses in Langerhans cell histiocytosis and propose that these crystals may be linked to extracellular trap-cell death (ETosis). This example challenges the conventional characterization of "necrosis" in Langerhans cell histiocytosis and underscores the importance of recognizing ETosis as a potential mechanism involved in the pathogenesis of Langerhans cell histiocytosis. Further studies are underway to validate significance of these findings in a larger cohort of Langerhans cell histiocytosis patients.

Clinical efficacy of all-trans retinoic acid for treating adult T cell leukemia.

PURPOSE: We previously reported that all-trans retinoic acid (ATRA) inhibited growth in human T-cell leukemia virus type I (HTLV-I)-positive T-cell lines and in fresh cells from patients with adult T cell leukemia (ATL). Here, we confirmed the clinical effects of ATRA in 20 patients with ATL. MATERIALS AND METHODS: The 20 patients (n = 20) with a median age of 56 (range 35-73) years who were diagnosed with ATL received ATRA orally. RESULTS: The efficacy of treatment was as follows: no complete response (CR), a partial response (PR) in 40% of the patients, no change (NC) in 45% of the patients, and a progressive disease (PD) in 15% of the patients. In seven acute-type ATL patients, a PR was achieved in two (28.5%), NC was observed in two (28.5%), and a PD was observed in three (42.8%). In three lymphoma-type ATL patients, a PR (100%) was achieved. Among four chronic-type ATL patients, a PR was achieved in one (25%) and NC was observed in the remaining three (75%). In six smoldering-type ATL patients, a PR was achieved in two (33.3%) and NC was observed in four (66.6%). The major side effects were headache (n = 5), transient liver dysfunction (n = 2), hyperlipidemia (n = 2), and anorexia (n = 1). CONCLUSION: These results indicated that ATRA might be a useful agent for the safe treatment of ATL.

Mutant type glutathione S-transferase theta 1 gene homologue to mTOR in myelodysplastic syndrome: possible clinical application of rapamycin.

In this study, we observed the expression of the GSTT-1 gene in patients with myelodysplastic syndrome (MDS) at the messenger RNA level. Reverse transcription-polymerase chain reaction (RT-PCR) for GSTT-1 was performed with a pair of primers complementary to the 5' coding section and the 3' coding section of the GSTT-1 cDNA for amplifying the 623-bp band. Among 20 patients with MDS, 8 patients showed the expected 623-bp band on RT-PCR, and 12 patients showed a 500-bp band on RT-PCR, indicating that a 123-bp sequence was deleted as a mutant of the GSTT-1 gene. Furthermore, a BLAST DNA search showed that the deletion of a 123 bp sequence creates a sequence that is 63% homologous to human FKBP-rapamycin associated protein (FRAP); this protein has been termed a mammalian target of rapamycin (mTOR). We respectively transfected the wild type and the mutant type GSTT-1 gene in an expression vector to two cell lines (K562 and HL-60). The stable transformants for the wild type and the mutant type GSTT-1 genes were made by G418 selection. Interestingly, rapamycin could induce significant growth inhibition of the stable transformants for mutant type GSTT-1, which was indicative of apoptosis, but not that of those for wild type GSTT-1. These results suggest that rapamycin could be included in the therapeutic modality for the patients with MDS who have the mTOR sequences in GSTT-1 gene.

Clinical importance of human herpes virus-8 and human immunodeficiency virus infection in primary effusion lymphoma.

Primary effusion lymphoma (PEL) is a rare type of non-Hodgkin lymphoma that usually develops in immunosuppressed patients infected with human herpes virus-8 (HHV-8) in conjunction with human immunodeficiency virus (HIV) infection. However, there are several reports of HHV-8-related HIV-negative cases and HHV-8-unrelated HIV-negative cases, mainly in immunodeficient and elderly patients. Here, we report one case of HHV-8-related HIV-negative PEL with gastric cancer (case 1) and one case of HHV-8-unrelated HIV-negative effusion-based lymphoma (case 2), both in elderly men. A 73-year-old man and a 79-year-old man were admitted because of lymphomatous effusions, and no mass was detectable in both cases. They were diagnosed as having malignant effusion lymphoma on the basis of cytological findings indicating atypical lymphoid cells and the expression of CD20 and CD79a. To detect evidence of HHV-8 infection in neoplastic cells, immunocytochemical staining for ORF73/ latent nuclear antigen-1 (LNA-1) was performed. The results revealed that case 1 was ORF73-positive, and case 2 was ORF73-negative. Rituximab-based chemotherapy (R-THPCOP: rituximab, pirarubicin, cyclophosphamide, vincristine, prednisolone) was administered to both patients and complete remission was achieved in both. Compared to most HIV-positive PEL cases, these two cases showed a good response to chemotherapy. In cases of PEL, we should focus on HHV-8 infection and HIV status for determining prognosis.

Interleukin-8 in the pathogenesis of primary central nervous system lymphoma in association with HIV infection.

The pathogenesis of acquired immunodeficiency syndrome-associated primary central nervous system lymphoma (AIDS-associated PCNSL) remains unclear. However, cell adhesion molecules have been reported to be strongly associated with PCNSL. In this study, we established Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) from HIV-positive patients (LCL(HIV)) and normal individuals (LCL(N)). The expression of CD18 antigen by LCL(HIV) was stronger than that by LCL(N). We performed a cell adhesion assay using ISO-HAS, which is the human hemangiosarcoma cell line and expresses intercellular adhesion molecule 1 (CD54). The binding rates of LCL(HIV) and ISO-HAS without stimulation were higher than those of LCL(N). Further, we demonstrated that azidothymidine or simvastatin inhibited the binding rates of LCL(HIV) and ISO-HAS more significantly than those of LCL(N). Further, the levels of interleukin (IL)-8, a CD18 inducer, were higher in LCL(HIV) than in LCL(N). We conclude that interaction between IL-8 and CD18 may be critical to AIDS-related PCNSL.

Analysis of bacteremia/fungemia and pneumonia accompanying acute myelogenous leukemia from 1987 to 2001 in the Japan Adult Leukemia Study Group.

We analyzed the incidence and prognosis of bacteremia/fungemia and pneumonia during remission induction therapy of a newly diagnosed acute myelogenous leukemia (AML) in the Japan Adult Leukemia Study Group treated with individual protocols of AML-87/-89 (1987-1991), AML-92 (1992-1995), AML-95 (1995-1997), and AML-97 (1997-2001). Bacteremia/fungemia was present in 251 of 2585 cases (9.7%); the causative microorganism was gram-positive bacteria (GPB) in 122 cases (49%), gram-negative bacteria (GNB) in 90 cases (36%), fungi (F) in 31 cases (12%), and polymicrobes (P) in 8 cases (3%). Particularly prevalent were Pseudomonas aeruginosa in 49 cases (20%), Staphylococcus epidermidis in 29 cases (12%), and Staphylococcus aureus in 25 cases (10%). With AML-87/-89, incidence of bacteremia/fungemia was 11.8% while it was 9.4% with AML-92, 8.7% with AML-95, and 9.2% with AML-97. The proportion of GPB, GNB, F, and P was 40, 41, 16, and 3% in AML-87/-89, 46, 40, 11, and 3% in AML-92, 48, 39, 11, and 2% in AML-95, and 59, 26, 11, and 4% in AML-97. The mortality rate by period was 26.5, 16.4, 14.0, and 6.8%, respectively. Pneumonia was found in 433 cases (16.8%); microbiological research covered 359 cases of AML-87/-89, AML-92, AML-97 and excluded AML-95 as there was no listing for the causative microorganism on questionnaires. Microbiologically documented pneumonia was found in 123 cases (34.3%), with GPB in 33 cases (27%), GNB in 28 cases (23%), F in 44 cases (36%), and P in 18 cases (15%); particularly prevalent were Aspergillus in 23 cases (19%), Staphylococcus aureus in 16 cases (13%), and Pseudomonas aeruginosa in 15 cases (12%). The incidence of pneumonia overall was 24.6% with AML-87/-89, 16.9% with AML-92, 13.9% with AML-95, and 12.9% with AML-97, with a mortality rate of 28.9, 33.3, 16.7, and 16.7%, respectively. Incidence of bacteremia/fungemia and pneumonia complicating AML has tended to decline in recent years, and mortality has also tended to improve.