Peripheral Stem Cell Transplant Recipients Research Articles

Diarrhea in peripheral stem cell transplant recipients: a developing country's experience.

We aimed to determine the frequency and microbiological causes of diarrhea occurring during the first 100 days in allogeneic (allo-) and autologous (auto-) stem cell transplantation (SCT) patients. A total of 452 patients who underwent transplantation due to hematological or solid organ malignancy were included. From the administration of the conditioning regimen up to day 100 post-transplant, diarrhea cases lasting at least three days with a minimum of three episodes per day were evaluated. Cases of diarrhea were observed in 94 patients out of 227 subjects who received allo-SCT and in 107 patients out of 225 who received auto-SCT. The incidence rate of diarrhea in both patients undergoing autologous and allogeneic transplant was 47.5% and 41.4%, respectively. The cause of the diarrhea could be detected in 20.5% of auto-SCT patients and in 30.8% of allo-SCT patients. Parasitic infections were frequently observed in both autologous and allogeneic transplant patients in the first 20 days. In the late period, significantly more patients developed diarrhea in the allo-SCT recipient group than in the auto-SCT recipients due to graft versus host disease (GVHD) and cytomegalovirus (CMV) colitis. This study revealed the causes of diarrhea and the prevalence and factors of parasitic infections in transplant patients in Turkey. All causative factors of diarrhea should be considered in detail, feces analyses should be evaluated for each patient, and endoscopic biopsy samples should be obtained when required in immunosuppressive patients undergoing stem cell transplantation.

Status Epilepticus Due to Severe HHV-6 Encephalitis in an Allogeneic Stem Cell Transplant Recipient

Reactivation of human herpes virus-6 (HHV-6) after stem cell transplantation occurs frequently. It is associated with clinical manifestations varying from nonspecific symptoms such as fevers or rash, to severe life threatening complications including post-transplantation limbic encephalitis. We report a case of severe HHV-6 encephalitis with viremia in an allogeneic peripheral stem cell transplant recipient who presented with status epilepticus unresponsive to antiepileptic therapy. With intravenous ganciclovir and supportive care, the patient’s condition improved. Awareness of HHV-6 infection in stem cell transplant recipients may help with early diagnosis and improved outcome.

Pharmacokinetics and Buccal Mucosal Concentrations of a 15 Milligram per Kilogram of Body Weight Total Dose of Liposomal Amphotericin B Administered as a Single Dose (15 mg/kg), Weekly Dose (7.5 mg/kg), or Daily Dose (1 mg/kg) in Peripheral Stem Cell Transplant Patients

The pharmacokinetics and safety of extended-interval dosing of prophylactic liposomal amphotericin B (L-AMB) in peripheral stem cell transplant recipients were evaluated. The patients received L-AMB daily at 1 mg/kg of body weight or weekly at 7.5 mg/kg or received L-AMB as a single dose (15 mg/kg). The buccal mucosal tissue concentrations of L-AMB were measured. Of the 24 patients enrolled, 5 withdrew after the initial dose due to an infusion-related reaction (n = 2) or significant increases in the serum creatinine (Scr) levels (n = 3). Weekly L-AMB dosing (7.5 mg/kg) produced mean plasma concentrations of >0.300 microg/ml for the first 7 days and >0.220 microg/ml for 7 days after the second dose. A single L-AMB dose (15 mg/kg) produced mean plasma concentrations of >0.491 microg/ml for at least 7 seven days. These concentrations are within the range of the MICs reported in the literature for susceptible strains of Candida and are at the lower limits of the MICs for Aspergillus spp. Extended-interval dosing produced buccal mucosal tissue concentrations well in excess of the MICs reported in the literature for susceptible strains of Candida and Aspergillus spp. Infusion-related reactions occurred in 24% of the patients. Baseline and end-of-study Scr, electrolyte (K+, Mg2+, PO4), and serum transaminase levels were similar across the dosage groups. Five (31%) patients met the nephrotoxicity definition prior to completion of the study. Patients in the weekly or single-dose groups experienced nephrotoxicity significantly faster than the patients in the daily dosing cohort. A weekly L-AMB dose (7.5 mg/kg) or a single L-AMB dose (15 mg/kg) produced sufficient concentrations in plasma and highly vascular tissue to warrant further studies of the safety, efficacy, and practicality of the weekly prophylactic administration of L-AMB.

Cerebral toxoplasmosis in an allogeneic peripheral stem cell transplant recipient: case report and review of literature

We present a patient who underwent allogeneic peripheral stem cell transplantation (PSCT) for chronic myelocytic leukemia. Twenty months after the PSCT he experienced status epilepticus. Magnetic resonance imaging (MRI) revealed a focus in the ventral thalamus-hypothalamus region. Using stereotactic biopsy with histology and specific polymerase chain reaction investigation from brain tissue, cerebral toxoplasmosis was diagnosed and treated with antiparasitic therapy. Early recognition of such serious and potentially lethal disease enabled prompt specific treatment. This case report emphasizes the role of stereotactic biopsy in diagnosis of cerebral toxoplasmosis. Other methods such as MRI are non-invasive but not sufficiently specific and sensitive.

Low Morbidity but Prolonged Viral Shedding Characterize Parainfluenza Virus 3 Infections in Allogeneic Peripheral Stem Cell Transplant Recipients.

Respiratory viruses including human parainfluenza virus 3 (hPIV3) may be significant causes of morbidity and mortality in patients undergoing allogeneic stem cell transplantation. It has been suggested that the acquisition of hPIV3 infections is independent of immunosuppression or transplant type and is driven primarily by patient exposure to the virus during periods of heightened community-wide or nosocomial activity. The incubation period for hPIV3 is 1–3 days and the duration of infectivity/ viral shedding in non-transplant patients is 1–2 weeks. Data regarding the duration of infectivity/ viral shedding and possible predictors of prolong infectivity in peripheral blood stem cell transplant patients (PBSCT) is limited. Of 56 recipients of sibling PBSCT seen at our insitution, 11 (6 inpatients and 5 outpatients) were positive for hPIV3 during a six weeks period, compared with only two positive cases recorded throughout the previous year. At the time of infection patients were between 1 and 7 weeks post transplant. The in-patient attack rate was 11%. Patients in whom respiratory virus infection was suspected were placed on respiratory isolation and followed with weekly nasopharygeal swab/wash (NPW). Care was also taken to limit patient contact of relatives or staff with respiratory symptoms. Most patients developed a flu like illness without major respiratory complications. No mortality was recorded. No case of hPIV 3 was recorded among patients with aplastic anemia receiving ATG in the unit during the same time-period. The median time to conversion from positive to negative hPIV 3 NPW was 2.0 weeks (range 1–6 weeks). The longest duration of viral shedding (six weeks) was in the only haplo-identical SCT patient, who was also the index case. No differences in duration of viral shedding was noted for conditioning regimen type (ablative vs non-ablative), days after transplant of viral acquisition (<15 or >15 days), cyclosporin levels (100–200 ng/l vs 201–400 ng/l), absolute neutrophil counts, absolute lymphocyte counts, CMV reactivation and co-existing peri-hPIV3 infections evidenced by positive blood, urine or sputum cultures. immunosuppression during the outbreak. Our study demonstrates that while hPIV infection in allogenic PBSCT patients has limited morbidity, prolonged duration of viral shedding in this group may contribute to recurrent cycles of epidemics or prolong outbreaks and establish an environmental (community/ nosocomial) contamination or “ping-pong” transmission from patients to asymptomatic health-care workers or family members and back. Our study also emphasize the importance of a universal policy for strict attention to infection-control practices and weekly surveillance NPW until patients are a symptomatic and NPW negative.