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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacterial pneumonia as an important complication of bone marrow transplantation (BMT) has not been subjected to comprehensive analysis. Two hundred fifty-five consecutive allogeneic and autologous BMT recipients, ranging in age from 1 month to 53 years, were prospectively followed for 3 days to 3 years (median, 108 days) for development of bacterial pneumonia. Etiology, place acquired, chest radiography, and outcome were recorded and the association between bacterial pneumonia and demographic and clinical variables was analyzed. Thirty-seven (15%) patients experienced 52 episodes of bacterial pneumonia: onset of 13 episodes occurred within 30 days after transplantation, 10 episodes occurred on days +31 to +100, and 29 episodes occurred thereafter. Bacterial pneumonia was the terminal event or contributed to fatal outcome in 8 patients (22% of bacterial pneumonia cases, 3% total study population). Mortality due to hospital-acquired pneumonia (6/21) was significantly higher than (P = 0.03). Bacterial pathogens were identified in 27 (52%) episodes. During the first 100 days after BMT, hospital-acquired Gram-negative bacteria predominated, caused mainly by Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter lwoffi, and Enterobacter cloacae. After day +100, community-acquired, Gram-positive bacteria predominated, particularly Streptococcus pneumoniae. Haemophilus influenzae occurred periodically. Considering all episodes, significant association was found between bacterial pneumonia and veno-occlusive disease (VOD) (P < 0.01) and chronic graft-versus-host disease (GVHD) (P < 0.02). For culture-positive episodes, the association between bacterial pneumonia and VOD was significant (P < 0.001) and borderline for acute GVHD (P = 0.07). It is concluded that VOD and GVHD are positively associated with post-BMT bacterial pneumonia. Its incidence, etiology, risk factors, and outcome are important considerations in its prevention and treatment.
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PMID:Bacterial pneumonia in recipients of bone marrow transplantation. A five-year prospective study. 757 Sep 75

Allogeneic bone marrow transplant patients are severely immunocompromised during the immediate posttransplant period, and the risk for common and opportunistic infections may persist for many months. The role of reimmunization for these patients, however, remains unsettled. We briefly review current concepts regarding the recapitulation of immunity from the totipotential hematopoietic stem cells in the donor marrow. The fact that various components of the new immune system mature at different rates can have clinical consequences with regard to specific infections. Most previously immunized patients become antibody seronegative within a few months after allogeneic marrow transplantation. Adoptive transfer of specific antibody-producing cells from the donor to the recipient has been demonstrated in small clinical trials, and is augmented when both donor and recipient are vaccinated. Passive transfer of immunity is more easily achieved to recall antigens than to neoantigens. Primary immunization requires prolonged antigenic stimulation and mature T-cell function or help from natural killer cells. Most healthy patients generate adequate antibody titers to vaccinations that are given 12 months after transplantation, but the presence of chronic graft-versus-host disease can diminish the response. Currently available vaccines have been evaluated in marrow transplant patients. Protein antigens such as tetanus and diphtheria toxoids are more immunogenic than polysaccharide antigens such as pneumococcal vaccine. The new polysaccharide-protein conjugate vaccines, such as the Hemophilus influenzae type b vaccine, also appear more immunogenic. Inactivated poliovirus vaccine has been used successfully. Relatively few data are available about hepatitis B or influenza vaccines. The literature supports the use of standard vaccines in allogeneic bone marrow transplant patients. However, more data on the optimal methods and timing of immunization are needed. We present guidelines for a reimmunization schedule.
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PMID:Reimmunization after allogeneic bone marrow transplantation. 770 53

There is a well documented risk of late infection following both splenectomy and bone marrow transplantation. In asplenic patients, the phagocytic and antibody producing roles of the spleen are lost and there is a lifelong susceptibility to infection which may be overwhelming and fatal. Patients most at risk are children, those with underlying lymphoproliferative disorders and those receiving immunosuppressive therapy. Although it is hard to prove benefit from preventative strategies, patients are likely to benefit from prophylactic antibiotic therapy and from immunisation with pneumococcal, Haemophilus influenzae-B and meningococcal vaccine given prior to splenectomy. Following an allogeneic bone marrow transplant (BMT), recovery of immune function takes up to a year. During this time, patients are at high risk from cytomegalovirus (CMV) and varicella zoster virus (VZV) infections and also from pneumocystis pneumonia. Prophylactic medications are used to good effect. The major threat of late infection occurs in patients with chronic graft versus host disease (cGVHD)--there is increased susceptibility to bacterial, fungal and viral infections. Many patients without cGVHD recover immune function fully and many develop antibodies to specific recall antigens. This does not occur in all patients and although there is a low risk of infection with organisms against which vaccines are available. If it is not possible to measure specific antibody titres and consequently offer selective re-immunisation, then a universal vaccination strategy should be in force. Response to vaccines is likely to be poor before one year post BMT. For autologous transplant recipients, immune recovery is probably complete and routine re-immunisation is not likely to offer much benefit. For both asplenic and bone marrow transplant patients, education of patient and physician is important.
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PMID:Prophylaxis against late infection following splenectomy and bone marrow transplant. 781 19

Bacterial complications develop mainly after transplantation during the period before engraftment takes place. Wound infections, urinary tract infection and pneumonia are the commonest complications of solid organ transplantation and generally involve Gram-negative bacilli and Staphylococcus aureus. However, Gram-positive cocci will predominate when selective oral antimicrobial prophylaxis is given as is frequently the case in bone marrow transplant recipients. Oromucositis, induced by total body irradiation or anthracyclines, result in more bacteraemia due to oral viridans streptococci. The use of central intravenous catheters leads to an increase in bacteraemia and infection due to coagulase-negative staphylococci. Patients requiring intensive care are also at risk of nosocomial infections including legionellosis. Once engraftment has occurred, there is much less risk of bacterial infection but patients remain vulnerable to the intracellular pathogens Listeria monocytogenes, non-typhoid salmonellae, Norcardia spp. and mycobacteria for as long as they require immunosuppression. Any rejection crisis must be treated aggressively with high-dose steroids or other agents which further undermine an already fragile immunity. In bone marrow transplant recipients, graft versus host disease and its treatment exerts a more profound effect on immunity and often coincides with cytomegalovirus infection which compromises the patient even further. Such patients are again at risk of infection with the same range of pathogens encountered during neutropenia since the oral mucosa, gut and catheter, if one is present, provide the same portals of entry. Immunosuppressive therapy, in some centres, is discontinued once the risk of graft versus host disease is reduced, although the reconstitution of the immune system is a lengthy process and there is a continued deficiency of IgG which renders patients unable to opsonise the encapsulated bacteria Streptococcus pneumonia and Haemophilus influenzae. In contrast to bone marrow transplant recipients, those with a solid organ transplant require life-long immunosuppression and so remain susceptible to infections with intracellular pathogens and, even with minimal immunosuppression, there will always be the risk that common bacteria will cause infection in unusual places and that uncommon organisms will be involved in apparently straightforward infections.
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PMID:Bacterial complications of transplantation: diagnosis and treatment. 860 44

In a randomized study, 20 adult allogeneic BMT recipients were vaccinated at 6 months and 22 at 18 months after BMT with Haemophilus influenzae type b (Hib)-diphtheria toxoid conjugate vaccine (PRP-D), and 23 recipients at 8 months and 21 at 20 months with pneumococcal polysaccharide (Pnc PS) vaccine. IgG1 and IgG2 subclasses of Pnc PS and Hib antibodies and avidities of Pnc PS IgG antibodies were determined by EIA in sera from patients with at least a two-fold total antibody response to Pnc type 3, 6B, 19F or PRP-D. The Pnc PS vaccine induced predominantly IgG1 Pnc 3 antibody production. Anti-Pnc 6B and 19F responses were mainly IgG2. The time of the Pnc PS vaccination, at 8 or 20 months after BMT, did not influence the IgG subclass response pattern. The PRP-D vaccine induced predominantly IgG2 anti-Hib production in the patients vaccinated at 6 months after BMT. The patients vaccinated at 18 months produced IgG1 and IgG2 antibodies more evenly. The same patient was able to produce predominantly IgG1 subclass antibodies to one antigen, Pnc 3, 6B, 19F or Hib, and IgG2 antibodies to another. The avidities of anti-Pnc 6B and 19F 1 month after vaccination were similar to those before vaccination, anti-Pnc 3 avidity was lower than before vaccination but matured in 15 months. The IgG subclass distribution and avidity were similar in the patients with and without chronic GVHD. In conclusion, the IgG response to Pnc type 3 was predominantly IgG1 as in infants and IgG2 to PRP-D, Pnc 6B, and 19F as in adults. Early vaccination after BMT or the presence of chronic GVHD did not impair the quality of response to Pnc PS and PRP-D vaccines.
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PMID:IgG subclasses and avidity of antibodies to polysaccharide antigens in allogeneic BMT recipients after vaccination with pneumococcal polysaccharide and Haemophilus influenzae type b conjugate vaccines. 1049 Jul 35

Patients undergoing hematopoietic stem cell transplantation (HSCT) experience a prolonged period of dysfunctional immunity associated with an increased risk of bacterial and viral infections. Effective approaches toward vaccinating patients against common pathogens are being explored but are limited by poor levels of responsiveness. Relevant studies examining the nature of reconstitution of cellular and humoral immunity and its impact on vaccination strategies against infectious pathogens are reviewed. Following transplantation, deficiencies in cellular immunity are characterized by the inversion of CD4/CD8 ratios, a decreased proliferative response to mitogens, and the development of anergy to recall antigens as measured by delayed-type hypersensitivity testing. The impact on humoral immunity consists of decreased levels of circulating immunoglobulin, impaired immunoglobulin class switching, and a loss of complexity in immunoglobulin gene rearrangement patterns. In this setting, a loss of protective immunity has been demonstrated against viral and bacterial pathogens previously targeted by childhood vaccination. Infections due to encapsulated bacterial organisms such as Streptococcus pneumoniae and Haemophilus influenzae type B remain prevalent even in the late posttransplantation period. The efficacy of vaccination following HSCT is influenced by the time elapsed since transplantation, the nature of the hematopoietic graft, the use of serial immunization, and the presence of graft-versus-host disease. Strategies to enhance vaccine efficacy include pretransplantation immunization of the stem cell donor and the use of cytokine adjuvants.
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PMID:Vaccination against infectious disease following hematopoietic stem cell transplantation. 1130 51

The duration of immunodeficiency following marrow transplantation is not known. Questionnaires were used to study the infection rates in 72 patients surviving 20 to 30 years after marrow grafting. Furthermore, in 33 of the 72 patients and in 16 donors (siblings who originally donated the marrow) leukocyte subsets were assessed by flow cytometry. T-cell receptor excision circles (TRECs), markers of T cells generated de novo, were quantitated by real-time polymerase chain reaction. Immunoglobulin G(2) (IgG(2)) and antigen-specific IgG levels were determined by enzyme-linked immunosorbent assay. Infections diagnosed more than [corrected] 15 years after transplantation occurred rarely. The average rate was 0.07 infections per patient-year (one infection every 14 years), excluding respiratory tract infections, gastroenteritis, lip sores, and hepatitis C. The counts of circulating monocytes, natural killer cells, B cells, CD4 T cells, and CD8 T cells in the patients were not lower than in the donors. The counts of TREC(+) CD4 T cells in transplant recipients younger than age 18 years (at the time of transplantation) were not different from the counts in their donors. In contrast, the counts of TREC(+) CD4 T cells were lower in transplant recipients age 18 years or older, even in those with no history of clinical extensive chronic graft-versus-host disease, compared with their donors. The levels of total IgG(2) and specific IgG against Haemophilus influenzae and Streptococcus pneumoniae were similar in patients and donors. Overall, the immunity of patients surviving 20 to 30 years after transplantation is normal or near normal. Patients who received transplants in adulthood have a clinically insignificant deficiency of de novo-generated CD4 T cells, suggesting that in these patients the posttransplantation thymic insufficiency may not be fully reversible.
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PMID:Immunity of patients surviving 20 to 30 years after allogeneic or syngeneic bone marrow transplantation. 1173 50

Functional hyposplenia/asplenia is a severe longterm complication after allogeneic stemcell transplantation predominantly seen in patients who suffer from extensive chronic graft versus host disease (cGvHD). The risk of acquiring an overwhelming infection with encapsulated bacteria is ca. four fold increased in patients with functional hyposplenia/asplenia. Therefore follow up of patients who have received allogeneic blood stem cells (bone marrow or peripheral blood stem cells) should embrace screening for functional hyposplenia. When functional hyposplenia is diagnosed triple vaccination against streptococcus pneumonia, Haemophilus influenza type B and Meningococcus neisseria should be considered. Goldstandard in diagnosing functional hyposplenia is hepatosplenic scintigraphy. We present the case of 37 year old female in whom sonography was indicative of functional hyposplenia. The diagnosis was confirmed by scintigraphy. Sonography including color coded duplex sonography is a safe and cost saving procedure. Sensitivity, Specificity and predictive value of the following sonographic finding: a) decreasing splenic size and b) diminished or absent parenchymal blood flow are currently evaluated in a prospective study.
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PMID:[Functional hyposplenia after allogenic bone marrow transplantation: a case report]. 1174 Jun 98

To obtain insight into the mechanism(s) of posttransplantation humoral immunodeficiency, we evaluated factors affecting serum antibody levels against polio, tetanus, Haemophilus influenzae, and Streptococcus pneumoniae in 87 patients. Patients with hematologic malignancies were randomized to receive marrow versus blood stem cells, which contain approximately 10 times more lymphocytes than marrow. Blood stem cell recipients did not have higher antibody levels than marrow recipients. Recipient pretransplantation antibody levels were correlated with the posttransplantation levels, especially in the first 6 months after transplantation when the correlation coefficients typically exceeded 0.6. Donor pretransplantation antibody levels had less of a correlation with posttransplantation levels in the recipient. Patient or donor age, total body irradiation, and graft-versus-host disease or its treatment appeared to have no effect. In conclusion, antibody levels in the first year after transplantation are affected primarily by pretransplantation antibody levels in the recipient and, to a lesser degree, in the donor. These findings suggest that immunization of the recipient and the donor before transplantation may be more effective in improving antibody immunity after transplantation than manipulating graft-versus-host disease, changing conditioning, or increasing the number of lymphocytes in the graft.
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PMID:Factors affecting antibody levels after allogeneic hematopoietic cell transplantation. 1250 30

We describe herein a case of nephrotic syndrome (NS) following allogeneic bone marrow transplantation (allo-BMT) for natural killer cell leukemia/lymphoma. Histologic studies defined the diagnosis as crescentic glomerulonephritis with massive immunoglobulin A (IgA) deposition, which has never been reported in NS cases following allo-BMT. Most of the massive infiltrated cells in the interstice were CD3(+)CD4(-)CD8(+) T cells derived from the donor. We observed mesangial deposition of Haemophilus parainfluenza outer membrane (OMHP) antigen and decreased glycosylation of the IgA1 hinge in the recipient's samples is consistent with the recently reported pathogenesis of IgA nephropathy. Further, the titer of IgA antibody against the donor serum was as high as other IgA nephropathy cases. These findings suggest that NS and crescentic glomerulonephritis in this case occurred as one of the forms of chronic graft-versus-host disease (GVHD), and that IgA deposition was associated with H parainfluenza and decreased glycosylation of the IgA1 hinge.
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PMID:Nephrotic syndrome with crescent formation and massive IgA deposition following allogeneic bone marrow transplantation for natural killer cell leukemia/lymphoma. 1254 67


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