Case report from the NIH Clinical Center: CNS nocardiosis

Successful Management of Combined BK Nephropathy and Nocardiosis in a Renal Transplant Recipient: Case Report

Nocardiosis is a life-threatening infection in immunocompromised patients. The prevalence of the disease ranges from 2.3% to 5% in renal allograft recipients. Here, we describe a case of BK nephropathy associating with nocardiosis with successful recovery. The 54-year-old male patient had end-stage kidney disease due to diabetic nephropathy associated with diabetic retinopathy, hypertension, and dyslipidemia. He started hemodialysis in October 2017; 2 years later, he underwent a deceased donor kidney transplant with 2 HLA mismatches and high panel reactive antibodies. He received desensitization with intravenous immunoglobulin and rituximab, received thymoglobulin as induction, and was maintained on prednisolone, mycophenolate mofetil, and tacrolimus. His serum creatinine decreased to a nadir of 90 μmol/L. He developed graft dysfunction, which was proven to be due to BK nephropathy. Therefore, mycophenolate mofetil was replaced with leflunomide in addition to intravenous immunoglobulin therapy. Ten months later, he had an accidental fall and sought an orthopedic evaluation. Magnetic resonance imaging of the lumbar spine and pelvis revealed lumbar spondylosis, avascular necrosis of the femoral head, and obturator muscle abscess. He was explored surgically, but the surgeon found no abscess or avascular hip necrosis. The patient's blood grew Nocardia, and he was readmitted and started imipenem and linezolid empirically. Brain and chest computed tomography scans ruled out any central nervous system or pulmonary involvement, but a bone scan revealed osteomyelitis of the right superior pubic ramus and prepubic swelling, which was confirmed by computed tomography to be an abscess in both obturator externus and internus. He continued the same antibiotics for 6 months based on culture and sensitivity. At follow-up, the patient has shown stable graft function (creatinine 155 μmol/L) with improved BK viremia with immunosuppression minimization. In renal transplant recipients, successful management of combined BK nephropathy and nocardiosis was feasible with minimization of immunosuppression and proper antimicrobial therapy.

Treatment of disseminated nocardiosis: a host-pathogen approach with adjuvant interferon gamma

Disseminated nocardiosis is a rare, life-threatening disease. Particularly at risk are immunocompromised patients, highlighting the crucial role of host factors. Conventional intensive antibiotic treatment has improved survival rates, but the overall prognosis of patients with disseminated nocardiosis remains unsatisfactory. In this Grand Round, we present a case of severe nocardiosis that did not respond to standard therapy. The patient's condition deteriorated when antibiotic therapy was given alone and improved substantially only after coadministration of interferon gamma. We review the literature relevant to adjuvant interferon gamma therapy of nocardiosis and discuss its potential harms and benefits. Overall, we consider such treatment as beneficial and low risk if the patient is followed-up closely. We conclude that clinicians should consider this regimen in refractory cases of severe Nocardia infection.

Isolated Nocardiosis, an Unrecognized Primary Immunodeficiency?

Nocardiosis is an infectious disease caused by the gram-positive bacterium Nocardia spp. Although it is commonly accepted that exposure to Nocardia is almost universal, only a small fraction of exposed individuals develop the disease, while the vast majority remain healthy. Nocardiosis has been described as an "opportunistic" disease of immunocompromised patients, suggesting that exposure to the pathogen is necessary, but a host predisposition is also required. Interestingly, increasing numbers of nocardiosis cases in individuals without any detected risk factors, i.e., without overt immunodeficiency, are being reported. Furthermore, a growing body of evidence have shown that selective susceptibility to a specific pathogen can be caused by a primary immunodeficiency (PID). This raises the question of whether an undiagnosed PID may cause nocardiosis affecting otherwise healthy individuals. This review summarizes the specific clinical and microbiological characteristics of patients with isolated nocardiosis published during the past 30 years. Furthermore, it gives an overview of the known human immune mechanisms to fend off Nocardia spp. obtained from the study of PIDs and patients under immunomodulatory therapies.

Nocardia amikacinitolerans and cytomegalovirus: distinctive clinical and radiological characterization of the rare etiologies of brain abscesses: report of 2 cases

Central nervous system infections in immunosuppressed patients are rare but potentially lethal complications that require swift diagnoses and intervention. While the differential diagnosis for new lesions on neuroradiological imaging of immunosuppressed patients typically includes infections and neoplasms, image-based heuristics to differentiate the two has been shown to have variable reliability.The authors describe 2 rare CNS infections in immunocompromised patients with atypical physical and radiological presentations. In the first case, a 59-year-old man, who had recently undergone a renal transplantation, was found to have multifocal Nocardia amikacinitolerans abscesses masquerading as neoplasms on diffusion-weighted imaging (DWI); in the second case, a 33-year-old man with suspected recurrent Hodgkin's lymphoma was found to have a nonpyogenic abscess with cytomegalovirus (CMV) encephalitis.As per review of the literature, this appears to be the first case of brain abscess caused by N. amikacinitolerans, a recently isolated superbug. Despite confirmation through brain biopsy later on in case 1, the initial radiological appearance was atypical, showing subtle diffusion restriction on DWI. Similarly, the authors present a case of CMV encephalitis that presented as a ring-enhancing lesion, which is extremely rare. Both cases draw attention to the reliability of neuroimaging in differentiating an abscess from a neoplasm.

Disseminated Nocardiosis in renal transplant recipient under therapy for pulmonary tuberculosis: a case report

Background

Nocardiosis is an opportunistic infection in a patient with underlying immune suppression and organ transplant. Clinical syndromes are varied and ranges from pulmonary, disseminated, cutaneous along with central nervous system involvement.

Case presentation

Herein, we report a rare case of disseminated pulmonary nocardiosis with cerebral manifestation in a 66 year-old-Nepali farmer; with a history of renal transplantation and undergoing therapy for pulmonary tuberculosis. Radiographic imaging revealed multiple opacities of varying sizes in bilateral lung field mediastinal, retroperitoneal lymphadenopathy, and ill-defined lesion with surrounding edema seen in left occipitoparietal region of brain. Bacteriological assessments of bronchoalveolar lavage and purulent fluid extracted intra-operatively from the lesion confirmed the case as Nocardiosis.

Conclusion

Disseminated Pulmonary nocardiosis with central nervous system involvement carries a poor prognosis. However, early diagnosis of the case, the administration of appropriate antibiotic, stereotactic aspiration alone or craniotomy has a successful outcomes even in a post renal transplant patient treated with anti tuberculosis treatment.

Successful treatment of multifoci nocardial brain abscesses: a case report and literature review

Brain nocardiosis is a serious opportunistic infection with high mortality. It exists more common in the immunocompromised hosts than the immunocompetent patients. Trimethoprim-sulfamethoxazole (TMP-SMZ) has been mostly considered as the choice of the medical treatment. Linezolid is also newly found to be effective to avoid the invasive surgery. The authors reported a case of patient with multifoci nocardial brain abscesses who failed with the combination of linezolid and TMP-SMZ alone but recovered with the surgery intervention and sequential antibiotics for 2 years. The patient lived a high quality life without recurrence and complications during the 30 months follow-up.Through the literature review, we recommend earlier stereotactic aspiration for diagnosis, combination with surgery intervention and prolonged anti-infection therapy would improve the prognosis.

Nocardia-induced granulocyte macrophage colony-stimulating factor is neutralized by autoantibodies in disseminated/extrapulmonary nocardiosis

BACKGROUND

Nocardia species cause infections in both immunocompromised and otherwise immunocompetent patients, although the mechanisms defining susceptibility in the latter group are elusive. Anticytokine autoantibodies are an emerging cause of pathogen-specific susceptibility in previously healthy human immunodeficiency virus-uninfected adults, including anti-granulocyte macrophage colony-stimulating factor (GM-CSF) autoantibodies with cryptococcal meningitis.

METHODS

Plasma from patients with disseminated/extrapulmonary nocardiosis and healthy controls was screened for anticytokine autoantibodies using a particle-based approach. Autoantibody function was assessed by intranuclear staining for GM-CSF-induced STAT5 phosphorylation in normal cells incubated with either patient or normal plasma. GM-CSF-mediated cellular activation by Nocardia was assessed by staining for intracellular cytokine production and intranuclear STAT5 phosphorylation.

RESULTS

We identified neutralizing anti-GM-CSF autoantibodies in 5 of 7 patients studied with central nervous system nocardiosis and in no healthy controls (n = 14). GM-CSF production was induced by Nocardia in vitro, suggesting a causative role for anti-GM-CSF autoantibodies in Nocardia susceptibility and dissemination.

CONCLUSIONS

In previously healthy adults with otherwise unexplained disseminated/extrapulmonary Nocardia infections, anti-GM-CSF autoantibodies should be considered. Their presence may suggest that these patients may be at risk for later development of pulmonary alveolar proteinosis or other opportunistic infections, and that patients may benefit from therapeutic GM-CSF administration.