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Biomedical subjects

K E Collingham

Publications and source records attributed to K E Collingham.

At least 19 recordsLinked to original sources

Enterovirus infections following T-cell depleted allogeneic transplants in adults.

Anecdotally, enteroviruses have been reported to cause serious complications post BMT, but the exact impact of these viruses in the post transplant period has not been reported. We prospectively evaluated stool, urine and throat samples for enteroviruses by viral culture together with relevant body fluids by RT-PCR in 64 allograft recipients receiving grafts T-cell depleted by Campath-1H, following both conventional and reduced-intensity conditioning. Seven patients (10.4%) developed nine episodes of enterovirus infections at a median of 146 days post transplant. Four episodes were associated with symptomatic illnesses, which could be attributable to enteroviruses. There was no mortality directly related to enteroviruses. There was no correlation between dose and mode of Campath-1H use, lymphocyte recovery, IgG and IgA levels and enterovirus isolation. Although enteroviruses tended to be more frequent in TBI-based conventional conditioning recipients, the only significant risk factor for enterovirus infection was unrelated donor graft. The low incidence of the severe enterovirus infections could have been related to a low lymphocyte count in this cohort in the absence of GVHD, particularly CD4+ count, which has been implicated in tissue damage in experimental animals. Further studies are needed to define its impact in different allograft settings.

Adolescent↗

Respiratory virus infections in adult T cell-depleted transplant recipients: the role of cellular immunity.

BACKGROUND: Little is known about the role of cellular immunity in respiratory virus infections after bone marrow transplantation. METHODS: Forty allograft recipients T-cell depleted with Campath antibodies were evaluated for respiratory virus infections in an active surveillance program with early initiation of antiviral therapy. RESULTS: Eighteen episodes of respiratory virus infection were detected in nine patients (22%) at a median of 95 days, with lower respiratory involvement in 44%. Fourteen episodes were treated with antiviral therapy for 7 to 46 days, with 11% mortality. Respiratory virus infections were more common in patients receiving Campath 100 mg in vivo, but delayed CD4+ recovery was the most significant risk factor. CONCLUSIONS: Respiratory virus infections are common and often recurrent in patients with severe CD4+ T lymphopenia. However, the mortality was low, which may have been due to early institution of antiviral treatment or reduced inflammatory damage to the lungs due to severe lymphopenia.

CD4-Positive T-Lymphocytes↗

Pre-emptive oral ribavirin therapy of paramyxovirus infections after haematopoietic stem cell transplantation: a pilot study.

Infections with the paramyxoviruses, respiratory syncytial virus (RSV) and parainfluenza virus (PIV) can result in serious morbidity and mortality after haemopoietic stem cell transplant (HSCT). Once pneumonia develops, the outcome of these infections is often poor despite anti-viral therapy. Aerosolised ribavirin has been evaluated as pre-emptive therapy for post-transplant RSV infections with some success. Due to the financial and logistic burden involved with the use of aerosolised ribavirin, we explored the efficacy and toxicity of oral ribavirin for pre-emptive therapy of post-transplant RSV and PIV infections in a dose escalating schedule (15-60 mg/kg/day). Five episodes each of RSV and PIV were treated in seven patients. Five patients were receiving treatment for GVHD and two acquired the infection in the pre-engraftment period. All the episodes of RSV infection improved with oral ribavirin with dose escalation to 30-45 mg/kg in three of them. On the other hand, only two of the five PIV infections improved with oral ribavirin. Of the three non-responders, two infections were acquired in the pre-engraftment period with one death from PIV pneumonia. Reversible anaemia was the only side-effect noted in patients treated for over 2 weeks. Thus, the use of oral ribavirin was well tolerated in the post-transplant period with no untoward toxicities. There was a trend towards better response in RSV infections, which needs to be further explored in controlled studies.

Administration, Oral↗

Cidofovir as primary pre-emptive therapy for post-transplant cytomegalovirus infections.

Pre-emptive antiviral therapy for CMV infection following allogeneic stem cell transplantation is an effective strategy for preventing CMV disease. This entails the logistic difficulty of daily intravenous therapy with ganciclovir or foscarnet to clinically asymptomatic patients. Cidofovir (CDV) is effective against CMV in vitro and has the practical advantage of weekly administration. However, there are limited data on the pre-emptive use of CDV in CMV infections. We carried out a pilot study exploring the efficacy and toxicity of CDV as primary pre-emptive therapy for CMV infections monitored by PCR-based assays. CDV was used at 5 mg/kg with probenecid and hydration, weekly for a maximum of 4 weeks, followed by fortnightly maintenance treatment. Four patients were treated with CDV and two of them responded. Both the non-responders developed CMV disease. There was no renal toxicity noted in any of the patients, but three patients had severe vomiting and one developed uveitis, which precluded maintenance treatment in the two responders. Following failure of CDV, foscarnet was effective in controlling the CMV infection in both patients, although the infection recurred in both. Thus, larger randomised studies are required before CDV can be recommended as a primary pre-emptive therapy for post-transplant CMV infections.

Adult↗

Resistance to antiviral drugs in herpes simplex virus infections among allogeneic stem cell transplant recipients: risk factors and prognostic significance.

Herpes simplex virus (HSV) infections in 75 allogeneic stem cell transplant recipients were analyzed. Sixteen patients developed HSV disease following transplantation. The risk factors were age, sex (females), unrelated donor graft, and graft-versus-host disease (GVHD) grade >/=2. Seven patients did not respond to acyclovir, and 3 patients failed to respond to foscarnet. Isolates from 4 patients developed resistance to acyclovir/penciclovir, and 3 patients had foscarnet-resistant isolates. The remaining 3 patients failed to respond to acyclovir, despite having sensitive isolates. All the isolates were sensitive to cidofovir, for which the IC(50) values correlated inversely with those for acyclovir (P=.01). The risk factors for clinical resistance to antiviral drugs were a GVHD grade >/=2 (P=.001) and the lack of ganciclovir prophylaxis (P=.01), with a higher nonrelapse mortality in the latter group (P<.0001). Clinical as well as in vitro resistance to antiviral drugs is common in patients with severe GVHD and is associated with a poor outcome.

Acyclovir↗

Isolation of viruses from stools in stem cell transplant recipients: a prospective surveillance study.

We prospectively examined stool specimens for enteric viruses in 75 stem cell transplant recipients (autologous 48, allogeneic 27) to determine the frequency and significance of these infections. Only six patients (8%) had a positive isolate. Five of these were allograft recipients (18%) compared to one autograft recipient (2%) (P = 0.02). Unrelated donor BMT recipients were at the highest risk for a viral isolate (OR = 10.5). Adenovirus was the commonest isolate (four patients). One patient each had an echovirus, enterovirus and small round structured virus identified. No correlation was found between the severity of gastro-intestinal symptoms and detection of a viral pathogen. There was no correlation with GVHD or CMV status. The only risk factor identified for isolation of an enterovirus was allogeneic BMT from an unrelated donor. There was a negative correlation with PBSC grafts. All the patients infected with an enteric virus had concomitant infection with other pathogens, compared to only 18% of uninfected patients (P = 0.001). The non-relapse mortality of the infected patients was 50% and only 7% in the uninfected patients (P = 0.01, OR = 12.5), although the isolated virus was the direct cause of death in one patient only. This study indicates a low rate of enteric virus isolation in recipients of PBSC grafts, both autologous and allogeneic. However, unrelated donor BMT is associated with a higher risk of enteric virus infection and an adverse outcome. Bone Marrow Transplantation (2000) 25, 277-282.

Adenoviridae↗

Adenovirus infections following haematopoietic cell transplantation: is there a role for adoptive immunotherapy?

Adenovirus has been recognised as an important pathogen in BMT recipients, especially in patients with GVHD and those receiving T cell-depleted allografts. We report adenovirus infections from an ongoing surveillance study in four patients after a non-myeloablative transplant and their improved outcome following withdrawal of immunosuppression in two patients and donor lymphocyte infusion for relapsed disease in the others. We discuss the control of adenovirus infections following immune manipulations and the feasibility of adoptive immunotherapy for post-transplant adenovirus infections.

Adenoviridae Infections↗

Fulminant adenovirus hepatitis following unrelated bone marrow transplantation: failure of intravenous ribavirin therapy.

Fulminant hepatic failure due to adenovirus infection is a rare complication following stem cell transplantation. We report this complication in an unrelated bone marrow transplant recipient 30 weeks post-transplant. Treatment with intravenous ribavirin was started within 36 h of admission, but he succumbed to unusually fulminant hepatic failure. Adenovirus type 2 was isolated from stool surveillance samples and from post-mortem liver samples. Adenovirus DNA was detected by PCR in blood and sputum samples at admission and was identified in post-mortem liver tissue by electron microscopy. Implications of the failure of ribavirin therapy are discussed.

Adenoviridae Infections↗

Prevalence of GB virus-C/hepatitis G virus infection in an antenatal population.

It is difficult to explain the high levels of infection seen with GBV-C/HGV if transmission relies on the parenteral route. A group of young women was investigated in order to establish the prevalence of infection in this age group of the general population and perhaps indicate other possible routes of infection, searching for both GBV-C/HGV RNA and HGV E2 antibodies. Evidence of infection was found in 11.8%. This is a higher prevalence than that found in blood donors but lower than in prostitutes. Evidence is accumulating from various groups that sexual/ close contact may result in transmission of this virus.

Adolescent↗

Chronic hepatitis in children after liver transplantation: role of hepatitis C virus and hepatitis G virus infections.

BACKGROUND/AIMS: Chronic graft hepatitis occurs in 20-30% adults after liver transplantation but the prevalence and causes in children are not known. In adults, hepatitis C virus infection is prevalent prior to transplantation and recurrent infection is a frequent cause of graft dysfunction. The significance of the recently described hepatitis G virus infection remains unproven. The aim of this study was to examine the role of hepatitis C virus and hepatitis G virus infection in chronic graft hepatitis after paediatric liver transplantation. METHODS: The prevalence of graft hepatitis and the role of hepatitis C virus and hepatitis G virus infections in 80 children after liver transplantation have been studied, with a median follow up of 4.4 years (range 0.4 to 10.7), and the persistence of hepatitis G infection in the presence of immunosuppression has been determined. RESULTS: Chronic graft hepatitis was diagnosed in 19/80 (24%) children and was most frequently seen in children transplanted for cryptogenic cirrhosis (71%). There was no significant difference in the prevalence of chronic hepatitis in those transplanted before or after donor anti-HCV screening. Hepatitis C infection occurred in three children transplanted prior to donor screening but in only one was associated with chronic hepatitis. Hepatitis G infection was found in 22/79 (28%) transplant recipients but was not associated with graft hepatitis. In 17/21 children hepatitis G infection persisted for a median of 5.2 years after transplantation. CONCLUSION: Chronic hepatitis occurred in 24% of children after liver transplantation, a similar prevalence to that in adults. Cryptogenic liver disease predisposed to graft hepatitis, but neither hepatitis C nor hepatitis G infection was associated. Hepatitis G virus caused a frequent and usually persistent infection after transplantation.

Adolescent↗

High prevalence of hepatitis G virus in bone marrow transplant recipients and patients treated for acute leukemia.

Hepatitis G virus (HGV) is a newly described virus that has been implicated in transfusion-associated hepatitis. The prevalence of HGV in a group of multitransfused patients with hematological malignancy was studied using a reverse transcription polymerase chain reaction technique. Transfusion histories and serum aspartate aminotransferase (AST) levels were recorded. HGV was detected in 29 of 60 (48%) patients. There was no difference in HGV positivity rates between those with normal AST levels and those with raised AST levels. Analysis of patients by treatment type showed that 20 of 33 (61%) patients who received a bone marrow transplantation procedure were HGV positive compared with 9 of 27 (33%) treated with conventional combination chemotherapy (P = .036) despite similar transfusion histories. There was no significant difference in HGV positivity between patients treated before the introduction of United Kingdom blood donor screening for hepatitis C virus antibody:18 of 39 (46%) and those treated after the introduction of screening 11 of 21 (52%). HGV infection appears to be extremely common in these patients; however, the clinical significance of these findings with respect to liver dysfunction is not yet clear.

Acute Disease↗

Hepatitis G virus infection in patients with bleeding disorders.

Eighty-two patients with bleeding, disorders registered with our centre were screened for infection with hepatitis G virus (HGV). 80 patients were positive for hepatitis C (HCV) antibodies, 66 of whom (83%) were HCV PCR positive. 11 patients (13%) were HGV RNA-positive, a similar prevalence rate to that of other studies of patients with bleeding disorders who received factor concentrates prior to the introduction of viral inactivation procedures. There was no significant difference in histological activity index (HAI) between the 10 HGV RNA-positive and the 31 HGV RNA-negative patients who underwent liver biopsy for assessment of HCV infection (median HAI scores 5.5, range 2-10 and four, range 0-10 respectively, P = 0.07). One patient in each group had established cirrhosis. In patients who underwent HCV quantitation there was no significant difference in HCV viral titre between HGV RNA-positive and negative patients (median HCV titre in HGV RNA-positive patients 2.10 x 10(5) DNA copies/ml (n = 8) range 4.17 x 10(2) to 4.17 x 10(6), median HCV titre in HGV RNA-negative patients 3.33 x 10(5) (n = 31) range 1.00 x 10(3) to 6.67 x 10(6), P = 0.68). In this study there was no evidence that individuals co-infected with HGV and HCV have more severe liver disease than those infected with HCV alone.

Adult↗

Diagnosis of primary human herpesvirus 6 and 7 infections in febrile infants by polymerase chain reaction.

Primary human herpesvirus 6 (HHV-6) and 7 (HHV-7) infections were identified in febrile children by qualitative and quantitative polymerase chain reaction (PCR) assays. Diagnosis was based on the differential detection of viral DNA in peripheral blood mononuclear cells (PBMC), but not in saliva. Six of 41 febrile infants, but none of seven non-febrile controls, were identified with primary infections (three HHV-6, three HHV-7). These children had significantly higher viral loads in PBMC (HHV-6, median 24213 genomes/10(6) PBMC; HHV-7, median 6,040,000 genomes/10(6) PBMC) than DNA-aemic, saliva PCR positive children (HHV-6, median 1606 genomes/10(6) PBMC, p < 0.01; HHV-7, median 7089 genomes/ 10(6) PBMC, p < 0.05). Viral DNA was detected in serum by PCR in only 50% of primary infections. All three children with primary HHV-7 infection had febrile convulsions. Thus PCR, including quantitative assays, may identify primary HHV-6 and HHV-7 infections when an appropriate combination of clinical specimens is used.

DNA, Viral↗

Fatal thrombocytopenia associated with Mycoplasma pneumoniae infection.

The case of a 21-year-old male who presented with pneumonia associated with thrombocytopenia and bleeding and who died from intracranial haemorrhage is described. Very high titres of complement fixing and agglutinating anti-mycoplasma antibodies indicated recent Mycoplasma pneumoniae infection. Possible links between thrombocytopenia and M. pneumoniae infection are discussed.

Adult↗