Diverse effects of clarithromycin and proposal of its clinical application for treating COVID-19 as a repurposing drug.

Outbreak of SARS-CoV-2 has been declared a pandemic, which is a serious threat to human health. The disease was named coronavirus disease 2019 (COVID-19). Until now, several vaccines and a few drugs have been approved for the prevention and treatment for COVID-19. Recently, the effect of some macrolides including clarithromycin (CAM) on COVID-19 has attracted attention. CAM is known to have diverse effects including immunomodulatory and immunosuppressive effects, autophagy inhibition, steroid sparing effect, reversibility of drug resistance, antineoplastic effect, antiviral effect as well as bacteriostatic/bactericidal effect. Many patients with COVID-19 died due to an overwhelming response of their own immune system characterized by the uncontrolled release of circulating inflammatory cytokines (cytokine release syndrome [CRS]). This CRS plays a major role in progressing pneumonia to acute respiratory distress syndrome (ARDS) in COVID-19 patients. It is noteworthy that CAM can suppress inflammatory cytokines responsible for CRS and also has anti-SARS-CoV-2 effect. Considering the rapidly progressive global disease burden of COVID 19, the application of CAM for treating COVID-19 needs to be urgently evaluated. Recently, an open-labeled non-randomized trial using CAM for treating COVID-19 (ACHIEVE) was initiated in Greece in May, 2020. Its results, though preprint, indicated that CAM treatment of patients with moderate COVID-19 was associated with early clinical improvement and containment of viral load. Thus, treatment with CAM as a single agent or combined with other anti-SARS CoV-2 drugs should be tried for treating COVID-19. In this article, we discussed the significance and usefulness of CAM in treating COVID-19.

Diverse effects of clarithromycin and proposal of its clinical application for treating COVID-19 as a repurposing drug

@#Outbreak of SARS-CoV-2 has been declared a pandemic, which is a serious threat to human health. The disease was named coronavirus disease 2019 (COVID-19). Until now, several vaccines and a few drugs have been approved for the prevention and treatment for COVID-19. Recently, the effect of some macrolides including clarithromycin (CAM) on COVID-19 has attracted attention. CAM is known to have diverse effects including immunomodulatory and immunosuppressive effects, autophagy inhibition, steroid sparing effect, reversibility of drug resistance, antineoplastic effect, antiviral effect as well as bacteriostatic/bactericidal effect. Many patients with COVID-19 died due to an overwhelming response of their own immune system characterized by the uncontrolled release of circulating inflammatory cytokines (cytokine release syndrome [CRS]). This CRS plays a major role in progressing pneumonia to acute respiratory distress syndrome (ARDS) in COVID-19 patients. It is noteworthy that CAM can suppress inflammatory cytokines responsible for CRS and also has anti-SARS-CoV-2 effect. Considering the rapidly progressive global disease burden of COVID- 19, the application of CAM for treating COVID-19 needs to be urgently evaluated. Recently, an open-labeled non-randomized trial using CAM for treating COVID-19 (ACHIEVE) was initiated in Greece in May, 2020. Its results, though preprint, indicated that CAM treatment of patients with moderate COVID-19 was associated with early clinical improvement and containment of viral load. Thus, treatment with CAM as a single agent or combined with other anti-SARSCoV- 2 drugs should be tried for treating COVID-19. In this article, we discussed the significance and usefulness of CAM in treating COVID-19.

Satisfactory remission in a case of IgD myeloma: effectiveness of glucocorticoid treatment.

IgD myeloma is an infrequent type of multiple myeloma and is characterized by an aggressive clinical behavior and a short survival time. No satisfactory treatments have thus far been established. Recently we treated a patient with IgD(lambda)-type myeloma with glucocorticoids, and succeeded in achieving a complete remission. This case seems to indicate a usefulness of glucocorticoid monotherapy for treating IgD myeloma.

Successful treatment of IBL-like T-cell lymphoma with cyclosporin A: two case reports with special reference to serum cytokine levels.

The prognosis of immunoblastic lymphadenopathy (IBL)-like T-cell lymphoma is grave, and its effective treatments have not been established. We applied oral cyclosporin A (CsA) treatment to two cases of IBL-like T-cell lymphoma, and succeeded in achieving complete remissions. CsA is known to have a suppressive effect on the immune system, most notably T-cells, but it also has a direct cytotoxic/apoptosis-inducing effect on lymphocytes. Its combined effects on neoplastic T-cells might have played an important role in achieving remission. In both cases, serum levels of interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-alpha) were elevated and decreased or returned to normal after achieving remissions. Considering that both cytokines represent monokines, it seems that a macrophage system is also involved in the pathogenesis of this disorder. Our two cases indicate that administration of CsA may be an effective therapy for IBL-like T-cell lymphoma.

Successful treatment of immunoblastic lymphadenopathy-like T-cell lymphoma with cyclosporin A.

Immunoblastic lymphadenopathy (IBL)-like T-cell lymphoma is considered to belong to peripheral T-cell lymphoma. Its prognosis is grave and effective treatments have not been established. Recently, we gave oral cyclosporin A (CsA) to a patient with IBL-like T-cell lymphoma, and succeeded in achieving dramatic remission. In this case, serum levels of interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF alpha) were elevated and decreased or returned to normal after achieving remission. Since CsA is a potent suppressor of the immune system and most notably T-cells, the immunosuppression of T-cell function might have played an important role in achieving remission in this case, although the precise mechanism still remains to be elucidated. The present case indicates that administration of CsA may be a very effective and safe selection of therapy for IBL-like T-cell lymphoma, as well as analogous disorders such as IBL and angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), thereby will contribute to improving the prognosis of patients with these diseases.

Morphological heterogeneity of myeloperoxidase-positive granules in normal circulating neutrophils: an ultrastructural study by cryosection.

Ultrastructural localization of myeloperoxidase (MPO) in the granules of human circulating neutrophils was examined by cryosection. On careful comparison with the morphological characteristics of the granules by conventional transmission electron microscopic study, large MPO-positive granules were divided into five types by immunocryoultramicrotomy using monoclonal antibody. Double staining of MPO and lactoferrin (or lysozyme) was also performed. Lactoferrin was generally detected in MPO-negative granules. Lysozyme immunostaining was present in MPO-positive and -negative granules. These data may suggest different functions among large MPO-positive granules of human circulating neutrophils.

Plural immunoglobulin synthesis in a single cell: an ultrastructural study of two cases with three M-proteins.

Electrophoresis revealed two cases of malignant lymphoma that each contained three M-proteins (IgM lambda.lgG kappa.lgG lambda and IgM lambda.IgM kappa.lgG kappa) in the sera. To determine cellular origin of each M-protein, atypical lymphoid and plasmacytoid cells of both cases were examined by electron microscopy. Atypical lymphoid and plasmacytoid cells possessed rough endoplasmic reticula (RERs) in varying degrees, as seen by conventional electron microscopy, and showed double-stainability for plural antibodies against immunoglobulins following double stainings of immunoelectron microscopy using immunogold staining. Rabbit antibodies against human IgM, lgG, free kappa-light chain and free lambda-light chain were used for the immunoelectron microscopic staining. By the double staining method, plural immunoglobulins, IgM/IgG, IgM/free kappa, IgM/free lambda, IgG/free kappa, IgG/free lambda and free kappa/free lambda, were simultaneously detected in varying degrees in the Golgi area, RERs, and dense bodies of lymphoid and plasmacytoid cells. In conclusion, this study directly exhibited, through electron microscopy, that plural immunoglobulins were synthesized at the same time in a single cell, and that the process of immunoglobulin synthesis in the lymphoid and plasmacytoid cells was different from that in a normal B-cell.

Durable remission after splenectomy for Waldenström's macroglobulinemia with massive splenomegaly in leukemic phase.

A patient with M-proteinemia (IgM, kappa type), lymphocytosis, anemia, and massive splenomegaly, was diagnosed as having Waldenström's macroglobulinemia (WM). Since this case was refractory to chemotherapy, splenic irradiation was performed, which effectively reduced the serum IgM level, spleen size, and lymphocyte counts; however, its effect was transient. Splenectomy was then carried out. The spleen contained abundant IgM-producing lymphocytes, and after splenectomy, the serum IgM values decreased and the peripheral blood counts returned to near normal. The transient increases of serum IgM occurred during two infectious episodes postoperatively. The patient has now been in a satisfactory remission for six years after splenectomy. The removal of an IgM-producing/secreting site and release from hypersplenism may be the major mechanisms involved in achieving the durable remission after splenectomy. In individual cases of WM with massive splenomegaly, we recommend splenectomy as part of the management of this disorder.

Polymerase chain reaction of Borrelia burgdorferi flagellin gene in Shulman syndrome.

A 49-year-old man presented a progressive swelling and induration of the skin resulting in flexion contracture. He had a history of two tick bites at the age of 17 and 47 years. Serum anti-Borrelia-burgdorferi antibody was positive; isolation of B. burgdorferi from the skin lesion was unsuccessful. He had eosinophilia (white blood cells 8,300/microlitre, 33% eosinophils) and hypergammaglobulinemia. The diagnosis of Shulman syndrome (eosinophilic fasciitis) from clinical and histological findings was established. A part of the flagellin gene of B. burgdorferi was detected in a skin biopsy sample by using the polymerase chain reaction method. To the best of our knowledge, this is the first report of detection of B.-burgdorferi-specific DNA from a skin sample of Shulman syndrome.

Satisfactory remission achieved by PUVA therapy in a case of crisis-type adult T-cell leukaemia/lymphoma with generalized cutaneous leukaemic cell infiltration.

We used PUVA therapy in a patient with crisis-type adult T-cell leukaemia/lymphoma and generalized cutaneous leukaemic cell infiltration. PUVA proved very effective in reducing leukaemic cells and in clearing the eruption. To understand the way in which PUVA produced a reduction in the number of leukaemic cells, we examined peripheral blood cells by light and electron microscopy. Light microscopy was of little help, but electron microscopy revealed that PUVA induced apoptosis-like changes in circulating leukaemic cells. This suggests that apoptosis-like changes in leukaemic cells might be the reason for the success of this treatment.

[Significance of PUVA therapy for adult T-cell leukemia/lymphoma--PUVA therapy can induce apoptosis in leukemic cells].

PUVA therapy is known to be effective for treating cutaneous T-cell lymphoma (CTCL). Considering that adult T-cell leukemia/lymphoma (ATL) represents a T-lymphocytic proliferative disorder similar to CTCL, it is likely that PUVA therapy is effective for treating ATL. We applied PUVA therapy to a 53 year old man with acute (i.e. crisis)-type ATL associated with generalized erythematous papules, and succeeded in achieving a complete remission (CR). To elucidate the mechanism of PUVA therapy in this case, we compared ultrastructures of leukemic cells obtained before and after PUVA therapy by electron microscopy, and found that PUVA therapy caused apoptosis in leukemic cells in the peripheral blood. In this paper, the antitumor mechanism of PUVA is discussed, and its efficacy is emphasized.

Ultrastructural study of periodic lamellar granules in human neutrophils.

Granules consisting of periodically arranged membranous lamellae and amorphous electron-opaque material, i.e., periodic lamellar granules, are present in human neutrophils. To date, no extensive ultrastructural studies have been carried out on these granules because of their infrequent presence in neutrophils. The bone marrow of 18 cases of chronic myeloproliferative disorders, including one case of chronic neutrophilic leukemia in which periodic lamellar granules were frequently seen in neutrophils, was investigated by electron microscopy. Periodic lamellar granules were seen in neutrophils in 12 of the 18 cases at varying frequencies. They were preferentially seen in immature neutrophils. The transverse profiles of these granules revealed concentric complete/incomplete rings or periodic parallel straight lines, i.e., various patterns of lamellar arrangement were present. Periodic lamellar granules were positive for myeloperoxidase and lysozyme at the electron-microscopic level. These results suggest that these granules represent a primary neutrophil granule subtype. However, their functional and pathologic significance remains unknown.

Light and electron microscope study of splenoportal milky spots in New Zealand black mice: comparison between splenoportal milky spots and aberrant spleens.

The omentum contains peculiar lymphoid tissues termed omental milky spots. In mice, similar milky spots (splenoportal milky spots) are present in splenoportal fat bands developing along the splenic artery. We found that New Zealand Black (NZB) mice, which are known to develop spontaneous autoimmune diseases, have well developed splenoportal milky spots. However, little is known about these milky spots. Thus we investigated splenoportal fat bands in NZB mice by light and electron microscopy. Splenoportal fat bands contained sporadic aberrant spleens as well as abundant milky spots. In addition, transitional forms between splenoportal milky spots and aberrant spleens, although sporadic, were present in the fat bands. Splenoportal milky spots were supplied with offshoots from the splenic artery and were composed of abundant lymphocytes with macrophages, plasma cells, granulocytes, megakaryocytes and various stromal cells. In addition, they showed active neutrophilic myelopoiesis and probable megakaryopoiesis. Aberrant spleens were also supplied by branches from the splenic artery. They showed active granulopoiesis, megakaryopoiesis, and erythropoiesis. The transitional forms resembled splenoportal milky spots in structure, but the former showed extramedullary haematopoiesis of three cell lineages. The morphological transition from aberrant spleens, via transitional forms, to splenoportal milky spots seems to indicate that splenoportal milky spots represent splenoid lymphoid tissues.

An ultrastructural study of primary granule subtypes in human neutrophils.

To investigate the heterogeneity of primary neutrophil granules, neutrophils in the bone marrow of 68 patients with hematologic and non-hematologic diseases were observed by electron microscopy. In addition to typical primary granules, 3 primary granule subtypes, i.e., parallel tubular granules (PTGs), fibrillar granules (FGs), and periodic lamellar granules (PLGs), were present in neutrophils. PTGs were found in only one case of chronic neutrophilic leukemia (CNL). On the other hand, FGs and PLGs were present in various cases at varying frequencies. Three subtype granules were seen preferentially in immature neutrophils. These subtypes were positive for myeloperoxidase, showing that they represent primary granules. In addition, hybrid PTG/FG granules, hybrid PTG/PLG granules, and hybrid FG/PLG granules were seen in the PTG-positive CNL case. This shows that a close association is present between PTGs, FGs, and PLGs.

Ultrastructure of fibrillar granules in human neutrophils.

Fibrillar granules (FGs) represent neutrophilic primary granules containing clustered filaments. We investigated neutrophils in the bone marrow obtained from 17 patients with chronic myeloproliferative disorders (CMPD) by electron microscopy. FG-positive neutrophils were seen in 15 of the 17 CMPDs with varying frequencies. The diameter of FG-filaments was 7-8 nm, showing that they corresponded to neither intermediate filaments nor actin filaments.

Erythropoiesis in mouse omental milky spots induced by erythropoietin: light and electron microscopic study.

The mouse omentum contains omental milky spots. They are abundantly present particularly in the omental fat band. In normal mice, the milky spots are composed of abundant lymphocytes/plasma cells with macrophages, granulocytes and various stromal cells. Unlike the lymph node, they show occasional neutrophilic myelopoiesis, though neither erythropoiesis nor megakaryopoiesis is present. We investigated the haematopoietic ability of the milky spots in ddY mice by administering intraperitoneal injections of erythropoietin (EPO), 500 units/body/day for 7 consecutive days. The omental fat bands were removed the day after the last EPO injection, and the milky spots were examined by light and electron microscopy. Small clusters of erythroblasts appeared in the milky spots in mice injected with EPO. In these clusters, erythroblasts in various maturation stages, dividing erythroblasts, denucleating erythroblasts and reticulocytes were seen by electron microscopy. These findings suggest that such clusters represent erythropoietic foci. The presence of erythropoietic foci in the milky spots was confirmed in all the mice injected with EPO. Megakaryocytes did not appear in the milky spots. These findings suggest that the milky spots have a latent erythropoietic ability, as well as active neutrophilic myelopoiesis.