Yl Kwong

CD56 ˛ NK lymphomas: clinicopathological features and prognosis

The surface molecule CD56 marks a category of malignant lymphoma of putative natural killer (NK) cell origin. We conducted a retrospective analysis of 24 cases of CD56+ NK lymphoma/leukaemia to define the clinicopathologic and prognostic features of this specific group of lymphomas. 56 cases of nasal lymphomas and 204 cases with an initial diagnosis of peripheral T‐cell lymphoma were retrospectively analysed. To specifically examine lymphomas of putative NK origin, only those that were negative for surface expression of CD3 but positive for CD56 were analysed. 24 cases were identified. The initial predominant sites of involvement were nasal (n =18), palate (n = 1), nodal (n = 1) and multi‐organ (n =4). Clinically, in patients with disease localized to one anatomical site (n = 20), most had symptoms confined to the nose, with a high percentage in early stage (I: 91%; IV: 9%). The marrow was not involved in any of these cases. However, patients with multi‐organ involvement at presentation (n = 4) behaved differently. All presented acutely with pancytopenia, hepatosplenomegaly, and marrow infiltration with haemophagocytosis. A leukaemic phase was observed in one case. Anthracycline containing combination chemotherapy resulted in complete remission in 75% of patients with localized disease, but only in 25% with multi‐organ involvement. The median survival of patients with localized disease was 12 months, compared with 2 months in the multi‐organ group (P =0.06); the disease‐free survival was significantly better in the former (P <0.01). The overall median survival of all patients was still poor at 11 months.

Chemotherapy and bone marrow transplantation for cancer patients who are also chronic hepatitis B carriers: a review of the problem.

In places where hepatitis B virus (HBV) infection is endemic, it is often necessary to give chemotherapy to or perform bone marrow transplantation for cancer patients who are also chronic HBV carriers. When standard chemotherapy was given to lymphoma patients, elevation of liver transaminases was observed in nearly half of those who were chronic HBV carriers. Ten percent of them became jaundiced, and the overall liver-related mortality was about 5%. There is currently no reliable way to predict the severity of HBV reactivation after chemotherapy. The risk is probably higher when the chemotherapy used is significantly immunosuppressive and the viral load in the liver is high. Different strategies have been used in an attempt to reduce the risk of HBV reactivation after chemotherapy, but they have not been very successful. Further studies will be required to determine the impact of newly available antiviral agents that are active against HBV. Recipients who are carriers of HBV or who receive hepatitis B surface antigen (HBsAg)-positive marrow are at increased risk of hepatitis B-related morbidity and mortality after bone marrow transplantation (BMT). There is evidence to suggest that prophylactic use of an active antiviral agent, such as famciclovir, may result in a significant decrease in the incidence and severity of HBV reactivation after BMT. Sustained serologic clearance of chronic HBV infection has also been reported in many HBsAg-positive marrow recipients receiving hepatitis B surface antibody-positive marrow from their allogeneic donors. There seems to be a transfer of both humoral and cellular immunity against HBV from donors to recipients. Further prospective studies are required to define the best approach to manage HBsAg-positive cancer patients receiving chemotherapy or BMT. It is recommended that all cancer patients be checked for their hepatitis B status before receiving chemotherapy or a bone marrow transplant, especially if they reside in or come from endemic areas of HBV infection.

A prospective study of symptomatic bacteremia following platelet transfusion and of its management

BACKGROUND: The danger of bacteremia due to contaminated platelets is not well known. There are also no established guidelines for the management of febrile reactions after platelet transfusion.

Natural killer cell lymphoma/leukemia: pathology and treatment

Malignancies arising from cells of putative natural killer (NK) cell origin have increasingly been recognized as distinct clinicopathological entities. These malignancies are marked by tumour cells with NK cell characteristics, including the immunophenotype of CD2+, surface CD3−, cytoplasmic CD3ϵ+, CD7±, and CD56+, and the genotype of germline T cell receptor gene. A consistent association with monoclonal Epstein–Barr virus infection in the tumour cell has been observed. These tumours are now regarded as putative NK cell lymphoma/leukemia. Pathologically, tumour cells show variable cytological appearances, with frequent angiocentricity and angioinvasion, associated with zonal necrosis. Clinically, most cases occur in the nasal area and upper aerodigestive tract. However, occurrence in non‐nasal sites such as the skin, gastrointestinal tract and testis is also observed. A particularly aggressive form of NK lymphoma/leukemia presents fulminantly as disseminated disease sometimes with a leukemic phase. All types of NK lymphoma/leukemia have an extremely poor prognosis with a median survival of less than a year. New modalities of treatment, including the use of high dose chemotherapy and stem cell rescue may be needed to improve treatment outcome.

Polyoma BK virus and haemorrhagic cystitis in haematopoietic stem cell transplantation: a changing paradigm

Summary:Haemorrhagic cystitis (HC) is a distinct clinical disorder of multiple aetiologies. It is characterized by painful haematuria due to haemorrhagic inflammation of the urinary bladder mucosa. In allogeneic haematopoietic stem cell transplantation (HSCT), HC occurring before engraftment is mostly transient and self-limiting, whereas that after engraftment is severe and sometimes life-threatening. Pre- and post-engraftment HC represent distinct disorders with different aetiologies and treatment implications. Recent data suggest that reactivation of the polyoma BK virus (BKV) plays a pivotal role in post-engraftment HC. Urotoxicity of the conditioning regimen and alloimmune reaction accompanying graft-versus-host disease (GVHD) upon engraftment are also important pathogenetic factors. Based on data from BKV studies, we propose that HC may be divided into three phases. In the first phase, the conditioning regimen damages uroepithelial cells, providing a milieu for BKV replication. In the second phase, unchecked uroepithelial BKV replication leads to BK viruria. In the last phase after engraftment, alloimmunity against BKV-infected uroepithelial cells leads to HC. The quinolone antibiotics suppress BKV replication in vivo and in vitro, suggesting that their prophylactic use may prevent the occurrence of HC.

Identification of del(6)(q21q25) as a recurring chromosomal abnormality in putative NK cell lymphoma/leukaemia

The putative natural killer (NK) cell lymphomas/leukaemias are a group of recently characterized haematolymphoid malignancies sharing an immunophenotype of CD3/Leu4− CD3ɛ+ CD56+, and a genotype of germline T‐cell receptor genes. They frequently present in extranodal sites and exhibit a highly aggressive clinical course. Information on the cytogenetic or molecular events leading to the tumourigenesis in this group of tumours is very scarce. In this study we analysed the cytogenetic findings of seven patients with CD56‐positive putative NK cell lymphoma/leukaemia. Three cases, including one nasal, one extranasal and one leukaemic form, showed a common region of deletion at 6q21‐q25, suggesting that this may be a non‐random chromosomal aberration.

Clinicopathological features and risk factors of clinically overt haemorrhagic cystitis complicating bone marrow transplantation.

Haemorrhagic cystitis (HC) is an important complication after bone marrow transplantation (BMT). Overt HC (grade ⩾2, gross haematuria, clot retention and impairment of renal function), clinically more important than mild and occult HC (grade 1, microscopic haematuria), leads to substantial morbidity and occasional mortality. We retrospectively analyzed 32 cases of clinically overt HC from a series of 236 BMT patients. Significant risk factors included the use of busulphan during conditioning, allogeneic BMT and acute GVHD. Logistic regression showed GVHD to be the most important risk factor. According to the time of engraftment, HC could be divided into pre- and post-engraftment subtypes. Pre-engraftment HC was brief, not more severe than grade 2, and subsided with supportive treatment. In contrast, post-engraftment HC was protracted, often of grade ⩾3, associated with severe GVHD, and required surgical intervention in many cases. Polyoma BK viruria, but not adenoviruria, could be demonstrated in both types of HC. The increased severity and association with GVHD of post-engraftment HC suggested that attack of urothelium by immunocompetent cells, possibly directed against BK viral antigens, might play a pathogenetic role.Bone Marrow Transplantation (2002) 29, 509–513. doi:10.1038/sj.bmt.1703415

Primary cardiac lymphoma

Primary cardiac lymphoma is a rare entity. We report on the clinicopathological features of 2 patients with primary cardiac lymphomas: one involving the right atrium resulting in intractable right heart failure, and the other involving the pericardium with massive pericardial effusion. In the first patient, sternotomy and surgical biopsy of the tumor were performed to arrive at the diagnosis. In the second patient, CT thorax and transesophageal echocardiography helped to diagnose the pericardial tumor, and cytological examination of the pericardial fluid established the pathological diagnosis of lymphoma. Combination chemotherapy (COPP) was started in both patients. The first patient died on the first day of chemotherapy due to intractable heart failure, while the second attained a partial response to chemotherapy but died of progressive disease 8 weeks later. This is followed by a literature review of 21 patients with primary cardiac lymphoma. In conclusion, the prognosis of primary cardiac tumor remains poor. Am. J. Hematol. 54:79–83, 1997

Real-time quantitative analysis of polyoma BK viremia and viruria in renal allograft recipients.

Polyoma BK virus (BKV) remains dormant in the urinary tract and circulating leucocytes and becomes reactivated during immunosuppression. BK viruria is prevalent in renal allograft recipients and BK viremia may be related to nephropathy and allograft rejection. How BK viruria and viremia are related in renal allograft patients is undefined. In this study, BKV copies in paired urine and serum samples of renal allograft recipients were measured by a real time quantitative polymerase chain reaction (Q-PCR) to test the hypothesis that their quantitative relationship might help to delineate viral reactivation patterns in these tissues. Urine and plasma samples from 44 renal allograft recipients with stable graft function were collected during outpatient follow-up and the genome copies of BKV were determined by Q-PCR. All patients showed quantifiable viremia and two groups of patients were identified: one group of patients (n=35) showed low viral load (median: 270/ml, range: 108-1000/ml) and the other group (n=9) with high viral load (median: 5x10(4)/ml, range: 2x10(4)-6x10(4)/ml). The corresponding median levels of viruria were 2000 and 900 ml. BK viremia and viruria were not related quantitatively. BK viremia/viruria were also not related to age, immunosuppression, time and source of renal grafts and serum creatinine levels. The absence of a quantitative relationship between BK viremia and viruria may reflect independent BKV reactivation in different tissues during immunosuppression.

Autologous bone marrow transplantation for primary nasal T/NK cell lymphoma

Primary nasal T or NK cell lymphoma is rarely seen in the Western population but is more common in the Orientals. Although it often presents with localized disease, the prognosis is generally poor. Long-term remission is seen in only 50% of patients with stage I disease despite aggressive treatment with chemotherapy and radiotherapy, and is invariably fatal if disseminated. Conventional chemotherapy for relapsed disease is usually not successful. Since 1992, three patients with relapsed primary nasal T/NK cell lymphoma have received high-dose chemotherapy with autologous bone marrow rescue at Queen Mary Hospital, Hong Kong. High-dose cyclophosphamide, BCNU and etoposide were used for conditioning. Two of them had a favourable response and remained in complete remission at 12 and 44 months post-transplant. The third patient unfortunately had a systemic relapse 6 months after the transplant. It appears from this experience that, like other aggressive non-Hodgkin’s lymphomas, high-dose chemotherapy and autologous bone marrow rescue is an effective treatment for relapsed primary nasal lymphoma following failure of conventional chemotherapy and radiotherapy.