A cute biphenotypic leukemia was diagnosed in a 29-year-old man who had previously been well. The patient immediately started a course of intensive induction chemotherapy; however, the leukemia was refractory. The patient required a total of 3 courses of chemotherapy before achieving complete remission.After his first course of chemotherapy, the patient felt weakness in both of his legs and numbness in his toes, and he was unable to urinate. A clinical examination showed upper motor neuron signs. The weakness improved with physiotherapy, but the numbness rapidly progressed during the second course of chemotherapy and subsequently stabilized with a sensory level at T5. The results of magnetic resonance imaging (MRI) of the patient's spine were normal, and an electroneuromyogram showed mixed polyneuropathy. The results of a lumbar puncture were unremarkable, leading us toward a diagnosis of toxic myelopathy, secondary to chemotherapy. We gave the patient 97.5 g (1g/kg body weight, intravenously) of immunoglobulins (Gamunex Biotherapeutics Inc.) empirically.As part of the neurologic investigation, we performed serologic testing the day after the patient received the immunoglobulins; the results showed reactivity on an enzyme immunoassay for human T -lymphotropic virus (HTLV). Tests to confirm infection were done at the National Laboratory for HIV Reference Services: an INNO-LIA HTLV I/II Score assay (Innogenetics, Belgium) returned a positive result, and the results of an in-house radioimmunoprecipitation assay were indeterminate. The final interpretation of these tests was indeterminate (Table 1). A polymerase chain reaction (PCR) test for HTLV could not be done.The patient and his parents were born in Canada. He was in a monogamous relationship, did not engage in high-risk behaviours and had never travelled to HTLV-endemic regions such as Asia. The result of repeat MRI of the patient's spine was normal. Baseline serologic testing for HTLV, done when the patient's leukemia was diagnosed, was negative (Table 1). A serum sample taken 2 weeks before the positive screening test was retrospectively analyzed and was found to be negative for HTLV. Follow-up serologic testing on a whole blood sample collected 2 months later returned negative results, including PCR testing for the HTLV-I and HTLV-II tax gene sequences. Finally, a sample of cerebrospinal fluid collected at the 2-month follow-up was tested; the results of all investigations were negative.Of note, the serum collected on the day after the patient received the immunoglobulin transfusion showed positive treponemal serology (Captia TA, Trinity Biotech), with negative non treponemal serology (Rapid Plasma Reagin; Pulse Scientific Inc.) and negative confirmatory tests for treponemal organisms (Treponema pallidum particle agglutination assay [Fujirebio] and syphilis INNO-LIA Score [Innogenetics]). Serologic testing for syphilis could not be done on the serum that had been collected before the immunoglobulin transfusion was given. However, 8 weeks after the transfus...

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2067 Background: Pneumococcal invasive infections are over 13 times more common among patients with hematological malignancies than in the general population. Hematopoietic stem cell transplant (HSCT) recipients, particularly those with chronic graft-versus-host disease (cGvHD), are especially vulnerable. Two types of vaccines are available for prevention: pneumococcal polysaccharide vaccine (PPSV) and pneumococcal conjugate vaccine (PCV). PPSV covers more serotypes, but concerns have been raised over immune response, particularly in immunocompromised patients. The primary goals of this study were to evaluate clinical impact of pneumococcal bacteremia, serotypes involved and resistance profile in our hematological population. Methods: We performed a retrospective study based at Hôpital Maisonneuve-Rosemont and Hôpital Notre-Dame du CHUM, both in Montreal, Canada. Among all positive blood cultures for Streptococcus pneumoniae between January 1st, 2003 and December 31st, 2011, we selected patients with hematological malignancies. We reviewed patients' charts and electronic files. Serotypes and antibiotic susceptibility testing were done by the Laboratoire de Santé Publique du Québec. The study was approved by the hospitals' ethics committee. Results: During the eight-year period, 54 episodes of pneumococcal bacteremia (in 52 patients) occurred among patients with hematological malignancies. Median age was 63.5 years (range 21 to 91); 44% were female. One patient was splenectomized. The main hematological malignancies were multiple myeloma (42%) and non-Hodgkin lymphoma (29%). There were 16 HSCT recipients: 10 allogeneic (8 with cGVHD) and 6 autologous. Twenty-nine patients (55%) were on chemotherapy, including 10 HSCT recipients. Among the patients with cGVHD, 3 were on trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis and 1 on pentamidine. At the time of the bacteremia, 81% of patients had a diagnosis of pneumonia (mean Fine score 118. Eleven patients were treated in the emergency department or in the outpatient clinic. Among the 43 hospitalized patients (80%), median hospitalization duration was 10 days. Intensive care unit admission was required for 9 episodes (17%). Eight patients died less than 30 days after the diagnosis of bacteremia, leading to a mortality rate of 15% and 19% among HSCT recipients. Vaccine history was not available in most patients' charts. However, all HSCT recipients should have received PPSV, as recommended in our institution. Twenty-four different serotypes were found. Theoretical coverage of these serotypes by the available vaccines was 26% for PCV-7, 35% for PCV-10, 50% for PCV-13, and 61% by PPSV; 33% episodes were not covered by any vaccine. Among patients with HSCT, the percentage of episodes not covered by any vaccine increased to 44%. PPSV covered 56% of episodes. Resistance to TMP-SMX was found in 17% of isolates. However, since 2006, all were susceptible. A third of isolates were resistant to erythromycin; the proportion of resistant isolates was higher among HSCT patients (50%). Only one isolate was resistant to fluoroquinolones, but was sensitive to all other antibiotics tested. One strain was of intermediate sensitivity to ceftriaxone, and was resistant to erythromycin and TMP-SMX. This patient was on TMP-SMX prophylaxis, and did not require admission. All strains were sensitive to penicillin and vancomycin. Conclusion: Pneumococcal bacteremia carries significant morbidity and mortality in patients with hematologic malignancies. Our mortality rate is similar to that found in other studies. Vaccination remains the cornerstone of prevention, but is imperfect in terms of immune response and coverage. One third of episodes were not covered by any available vaccine, and this proportion increased among HSCT recipients. Antibacterial prophylaxis in patients with cGVHD is therefore important and penicillin remains a good choice. In terms of treatment options for respiratory infection, given the high erythromycin resistance rate (34% vs. 20–25% found in the general population), macrolides should not be used as single agents. Third generation cephalosporins and fluoroquinolone resistance is very low, making it an interesting choices for respiratory infections. Disclosures: Labbé: Pfizer: Research Funding.