1H Magnetic Resonance in the Study of Hepatic Encephalopathy in Humans

¹H magnetic resonance (¹H MR) studies of the brain in patients with liver diseases have shown several abnormalities that may be relevant for the pathogenesis of hepatic encephalopathy. ¹H magnetic resonance imaging shows a typical pallidal hyperintensity on T ₁-weighted images. This abnormality appears to be secondary to the accumulation of manganese in basal ganglia because of portal-systemic shunting. No direct correlation between the magnitude of pallidal hyperintensity and the grade of hepatic encephalopathy has been found, but some studies have related pallidal hyperintensity to parkinsonism. ¹H magnetic resonance spectroscopy shows relative to creatine an increase in glutamine/glutamate (Glx) signal and a decrease of choline containing compounds (Cho) and myo-inositol. Abnormalities in the Glx signal have been interpreted as an increase in brain glutamine secondary to the metabolism of ammonia in astrocytes. Disturbances of Cho and myo-inositol have been interpreted as a compensatory response to the increase in intracellular osmolality caused by the accumulation of glutamine in astrocytes. In addition, magnetization transfer imaging shows signs compatible with low-grade cerebral edema. Altogether, ¹H MR studies suggest the accumulation of manganese and the development of osmotic abnormalities in the brain of patients with cirrhosis. These abnormalities appear to participate in some of the neurological manifestations of hepatic encephalopathy.     

Current and future applications of magnetic resonance imaging and spectroscopy of the brain in hepatic encephalopathy

Hepatic encephalopathy (HE) is a common neuro-psychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subciinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging (MRI) techniques provide a non-invasive means of assessment of changes in brain volume (coregistered MRI) and impaired brain function (fMRI), while proton magnetic resonance spectroscopy (1H MRS) detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.     

Disseminated Nocardia transvalensis infection with osteomyelitis and multiple brain abscesses

A case of Nocardia transvalensis osteomyelitis and cerebral abscesses is described. To the authors' knowledge, the patient described here represents the first reported case of primary N. transvalensis leg abscess with contiguous osteomyelitis of the femur and secondary brain abscesses. The literature on nocardial osteomyelitis and cerebral nocardiosis is reviewed, and treatment of both conditions is discussed. The interactions between the immune system and nocardial organisms are described, as well as the host defense defects in diabetic patients as they relate to pathogenicity of the bacteria. Finally, the patient's paradoxical therapeutic response of resolving brain abscesses with concomitant unresolving osteomyelitis is discussed, as well as its implications for managing similar cases in the future.     

Increased availability of central benzodiazepine receptors in patients with chronic hepatic encephalopathy and alcohol related cirrhosis

BACKGROUND/AIMS: To measure cerebral benzodiazepine receptor binding using (11)C-flumazenil positron emission tomography in patients with stable chronic hepatic encephalopathy, who were also characterised by proton magnetic resonance spectroscopy. METHODS: Six abstinent patients of mean age 61 years with alcohol related cirrhosis and grade I-II hepatic encephalopathy and 11 matched healthy volunteers were studied. Each patient's encephalopathy was defined according to clinical, psychometric, electroencephalographic, and magnetic resonance spectroscopy criteria. Using positron emission tomography, the brain volume of distribution of (11)C-flumazenil was obtained; this reflects benzodiazepine receptor availability. Proton magnetic resonance spectra were acquired at 1.5 T using a multivoxel technique; peak area ratios were calculated for choline, glutamine/glutamate, N-acetylaspartate, and creatine resonances. RESULTS: The mean volume of distribution of (11)C-flumazenil was significantly higher in the cortex, cerebellum, and the basal ganglia in the patients compared with controls (p<0.001). In the patient group, the mean glutamine/glutamate to creatine ratio was significantly increased and the mean choline to creatine ratio was significantly decreased in all brain areas, compared with healthy volunteers. However, the N-acetylaspartate to creatine ratio was unchanged compared with controls. CONCLUSIONS: The spectroscopy results reflect the cerebral metabolic derangement associated with hepatic encephalopathy. Stable grade I-II chronic hepatic encephalopathy in alcohol related cirrhosis may be associated with increased cerebral benzodiazepine receptor availability. However, a direct effect of previous chronic exposure to alcohol cannot be excluded.     

Multiple Brain Abscesses Due to Aspergillus Fumigatus in a Patient With Liver Cirrhosis: A Case Report

Invasive cerebral aspergillosis always developed in immunocompromised host. Early diagnosis may save life in this critical condition; however, it is difficult to reach. Herein, we presented an unusual case of invasive cerebral aspergillosis in a cirrhotic patient.A 47-year-old man presented with progressive deterioration of consciousness for three days. The patient had a history of alcoholic liver cirrhosis, Child-Pugh class C. Magnetic resonance imaging (MRI) of brain showed multi-focal parenchymal lesions, which was consistent with multiple brain abscesses. The diagnosis of invasive cerebral aspergillosis was made by molecular based laboratory methods including Aspergillus galactomannan antigen assay and oligonucleotide array. Despite treatment with the antifungal agent, Amphotericin B, the patient died at the ninth day of hospitalization.Our findings suggest that liver cirrhosis can be one of risk factors of invasive cerebral aspergillosis, and support the diagnosing usefulness of MRI, Aspergillus galactomannan antigen assay, and oligonucleotide array.     

Insights into the acute cerebral metabolic changes associated with childhood diabetes.

AIMS: Type 1 diabetes is a prevalent chronic disease in childhood with the commonest single cause of death being cerebral oedema in the context of diabetic ketoacidosis (DKA). The nature of the alterations in cerebral metabolism that may result in vulnerability to neuronal injury remains unknown. The aim of this study was to analyse the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) brain data from eight children with diabetes following acute presentation with hyperglycaemia with or without ketoacidosis, to determine the nature and timing of any alterations in cerebral structure and metabolism. METHODS: This study used MRI and MRS to investigate regional cerebral abnormalities in a small series of diabetic patients with and without DKA. Changes were compared with the clinical and biochemical features of the patients studied. RESULTS: Our small series of patients all demonstrated abnormal signal changes in the frontal region on fluid attenuated inversion recovery (FLAIR) MR imaging, suggestive of oedema, and spectroscopic abnormalities of increased taurine, myoinositol and glucose levels. The MR abnormalities varied in severity but did not correlate with any clinical or biochemical parameters. CONCLUSIONS: These changes indicate that many diabetic children, particularly at presentation, may have alterations in cerebral metabolism with implications for the pathogenesis and treatment of the cerebral complications of DKA. In addition, our findings suggest that increased taurine may be one of the important differentiating factors in the response of the brain of diabetic children to DKA that may reflect an increase in their vulnerability to cerebral oedema compared with diabetic adults.     

Disseminated nocardiosis after unrelated bone marrow transplantation

Nocardiosis is a rare bacterial infection occurring mainly in patients with deficient cell‐mediated immunity. Although disseminated nocardiosis after allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is a rare complication, it is associated with high mortality. Moreover, after allo‐HSCT, nocardiosis may be mistaken for other bacterial or fungal infections because clinical and radiographic findings of pulmonary, cerebral, and cutaneous nocardiosis lesions are non‐specific. Here, we report a case of disseminated nocardiosis (caused by Nocardia abscessus) with skin, pulmonary, liver, lymph node, and multiple brain abscesses in a patient after allo‐HSCT. The patient initially responded clinically and radiographically to imipenem/cilastin and trimethoprim‐sulfamethoxazole therapy. Clinicians should be aware of the possibility of nocardiosis in allo‐HSCT recipients who are treated with multiple immunosuppressive agents to control chronic graft‐versus‐host disease. Accurate diagnosis and identification of disseminated nocardiosis is important to ensure administration of the correct antibiotic regimen.     

Imaging analysis of the brain in a primate model of cerebral malaria

This paper reviews our studies concerning imaging analysis of the brain in a primate model of cerebral malaria. To elucidate the clinical features of cerebral malaria, we performed positron emission tomography with ¹⁸F-fluorodeoxyglucose (FDG-PET) scanning and magnetic resonance imaging (MRI) of the brain in Japanese macaques (Macaca fuscata) infected with Plasmodium coatneyi, a primate model of severe human malaria with cerebral involvement. On FDG-PET scanning, we observed diffuse and heterogeneous reduction of metabolism in the cerebral cortex in the acute phase of malaria infection. Although the monkey exhibited severe clinical signs, MR imaging did not reveal any significant changes during the course of infection. Histopathologic examination frequently revealed preferential sequestration of PRBCs in the cerebral and cerebellum capillaries, but neither parenchymal injury nor neuronal necrosis was found in the tissues. These results suggest that heterogeneous metabolic reduction and lack of abnormalities on MRI in the acute phase of CM may be due to any avoidance mechanisms from ischemia caused by sequestration. This may be one reason why more than half of CM patients have no neurological sequelae following recovery.     

Localised Cerebral Phosphorus-31 MR Spectroscopy in Man Before and Immediately after Coronary Bypass Surgery with Hypothermic Cardiopulmonary Bypass

Coronary artery bypass surgery classically is undertaken with hypothermic cardiopulmonary bypass (CPB). There is a high incidence of neuropsychological defects after cardiac surgery, which may be related to cerebral ischaemia during the rewarming period. In this study, phosphorus-31 magnetic resonance spectroscopy (³¹P MRS) was used to identify changes in cerebral ³¹P MR spectra in patients before and immediately after hypothermic CPB. Four neurologically normal patients undergoing coronary artery bypass surgery were studied. Localised cerebral ³¹P MRS (TR 5000 ms) was performed at 1.5 Tesla on each patient the day before and within an hour of completion of surgery. Peak areas for phosphomonoesters (PME), inorganic phosphate (Pi), phosphodiesters (PDE), phosphocreatine (PCr) and beta ATP (ATP) were measured. Metabolite peak area ratios and relative percentages of each ³¹P MR resonance with respect to the total ³¹P MR signal were calculated. In the post-operative MR spectra, each patient displayed a marked reduction in Pi/ATP and increase in PCr/Pi ratios. Spectral changes in percentage metabolite signals following surgery varied both in magnitude and pattern between patients. In two patients there was an increased postoperative percentage PME and percentage PCr with a decrease in percentage ATP. The converse was found in the other two patients, but all four subjects displayed a markedly decreased percentage Pi after CPB. These metabolite changes probably reflect rebound phosphorylation in the immediate postoperative period and suggest increased metabolic activity in the hyperaemic brain on rewarming from hypothermic CPB.     

Varicella-zoster virus limbic encephalitis in an immunocompromised patient.

A case of limbic encephalitis in a patient who had undergone prolonged immunosuppressive treatment with i.v. cyclophosphamide and oral prednisolone for a microscopic polyangeitis is reported. A brain MRI scan revealed symmetric mesial temporal lobe lesions. Studies of cerebrospinal fluid (CSF) revealed a positive PCR for varicella-zoster virus (VZV) DNA in 2 separate samples. Owing to a delay in diagnosis, intravenous acyclovir was initiated only after 11 d of symptoms. PCR of CSF for VZV DNA became negative on day 14 of treatment while brain lesions had resolved on subsequent MRI scans. Limbic encephalitis is a novel form of VZV infection. When brain imaging is suggestive of limbic encephalitis in an immunocompromised patient, PCR of CSF for VZV DNA should be performed, as early antiviral treatment may improve the outcome.     

An adult case of influenza-associated encephalitis successfully treated with high dose intravenous immunoglobulins

A 73-year-old man was admitted to our hospital with a high fever and left paresis. A rapid diagnosis test was positive for influenza A was positive by rapid diagnosis test and diffusion-weighted MRI imaging of the brain showed a high intensity lesion of the right cerebral peduncle. The patient was therefore diagnosed as having influenza A virus infection complicated with lacunar infarction. In spite of initial treatment with oseltamivir and anticoagulant therapy, he lost consciousness eight hours after admission. The high intensity lesion of the cerebral peduncle enlarged and new lesions in the thalamus, hippocampus and calcarine cortex were detected with brain MRI. Additionally, an electroencephalographic study showed an entire slow wave and as the other causative pathogens of central nerve system infection were not detected, the likely diagnosis was influenza-associated encephalitis. We administered a high dose of intravenous immunoglobulin since the low-grade fever and mild unconscious state had continued in spite of the treatment with methylprednisolone pulse therapy. His consciousness was restored and body temperature became normal immediately. We could confirm the efficacy of our treatment by measurement of IL-6 levels in the serum and cerebrospinal fluid during the entire clinical course. In conclusion, a high dose of intravenous immunoglobulin therapy might be one of the effective treatments for influenza-associated encephalitis.     

Differentiation among metastatic brain tumors, radiation necroses, and brain abscesses using proton magnetic resonance spectroscopy

Magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) were evaluated for differentiating metastatic brain tumors, radiation necroses, and brain abscesses. Twelve histologically verified lesions in 12 patients were studied using preoperative MRI and proton MRS. The signal intensities of four major metabolites, N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine and phosphocreatine (Cr), and lactate (Lac), were observed over the region of interest. Metastatic brain tumors showed a decrease in NAA/Cr and an increase in Cho/Cr ratios. Radiation necroses showed a decrease in NAA/Cr and no change in Cho/Cr ratios. Brain abscesses showed an increase in Lac/Cr ratio. Correlation with histopathologic findings showed that a high Cho signal was suggestive of a metastatic brain tumor. Lac signals were observed in brain abscesses, presumably reflecting the anerobic glycolysis of living cells. Although more cases and studies are necessary, metabolic information provided by proton MRS combined with MRI is useful for differentiating among metastatic brain tumors, radiation necroses, and brain abscesses.     

MR imaging and spectroscopy of the basal ganglia in chronic liver disease: Correlation of T1-weighted contrast measurements with abnormalities in proton and phosphorus-31 MR spectra

The purpose of this study was to correlate the hyperintensity in the globus pallidus seen on T₁-weighted magnetic resonance imaging (MRI) of the brain in chronic liver disease with changes in metabolite ratios measured from both proton and phosphorus-31 magnetic resonance spectroscopy (MRS) localised to the basal ganglia. T₁-weighted spin echo (T₁ WSE) images were obtained in 21 patients with biopsy-proven cirrhosis (nine Child's grade A, eight Child's grade B and four Child's grade C). Four subjects showed no evidence of neuropsychiatric impairment on clinical, psychometric and electrophysiological testing, four showed evidence of subclinical hepatic encephalopathy and 13 had overt hepatic encephalopathy. Signal intensities of the globus pallidus and adjacent brain parenchyma were measured and contrast calculated, which correlated with the severity of the underlying liver disease, when graded according to the Pugh's score (p<0.05). Proton MRS of the basal ganglia was performed in 12 patients and 14 healthy volunteers. Peak area ratios of choline (Cho), glutamine and glutamate (Glx) and N-acetylaspartate relative to creatine (Cr) were measured. Significant reductions in mean Cho/Cr and elevations in mean Glx/Cr ratios were observed in the patient population. Phosphorus-31 MRS of the basal ganglia was performed in the remaining nine patients and in 15 healthy volunteers. Peak area ratios of phosphomonoesters (PME), inorganic phosphate, phosphodiesters (PDE) and phosphocreatine relative to BATP (ATP) were then measured. Mean values of PME/ATP and PDE/ATP were significantly lower in the patient population. No correlation was found between the T₁WSE MRI contrast measurements of the globus pallidus and the abnormalities in the metabolite ratios measured from either proton or phosphorus-31 MR spectra. Our results suggest that pallidal hyperintensity seen on T₁WSE MR imaging of patients with chronic liver disease is not related to the functional abnormalities of the brain observed in hepatic encephalopathy.     

Infectious CNS disease as a differential diagnosis in systemic rheumatic diseases: three case reports and a review of the literature

BACKGROUND: Immunosuppressive treatment of rheumatic diseases may be associated with several opportunistic infections of the brain. The differentiation between primary central nervous system (CNS) involvement and CNS infection may be difficult, leading to delayed diagnosis. OBJECTIVE: To differentiate between CNS involvement and CNS infection in systemic rheumatic diseases. Methods and results: Three patients with either longstanding or suspected systemic rheumatic diseases (systemic lupus erythematodes, Wegener's granulomatosis, and cerebral vasculitis) who presented with various neuropsychiatric symptoms are described. All three patients were pretreated with different immunosuppressive drugs (leflunomide, methotrexate, cyclophosphamide) in combination with corticosteroids. Magnetic resonance imaging of the brain was suggestive of infectious disease, which was confirmed by cerebrospinal fluid analysis or stereotactic brain biopsy (progressive multifocal leucoencephalopathy (PML) in two and nocardiosis in one patient). DISCUSSION: More than 20 cases of PML or cerebral nocardiosis in patients receiving corticosteroids and cytotoxic drugs for rheumatic disease have been reported. The clinical aspects of opportunistic CNS infections and the role of brain imaging, cerebrospinal fluid analysis and stereotactic brain biopsy in the differential diagnosis are reviewed.     

Pulmonary nocardiosis complicated with multiple brain abscess]

A 52-year-old woman was taking 10 mg of prednisolone on alternate days for the treatment of autoimmune hemolytic anemia. She was informed of an abnormality on a chest X-ray film about 3 months previously and was admitted to our hospital with sudden onset of chest pain and fever. On the following day, she underwent transthoracic needle biopsy and the lung lesion was diagnosed as pulmonary nocardiosis. She showed improvement of fever and the lung lesion with administration of an antibacterial agent, but suddenly developed vomiting and headache. Brain MRI revealed multiple brain abscesses at more than 20 sites. A subsequent change of the antibacterial agent achieved control of the lung lesion and brain lesions. This case shows that prednisolone can cause nocardiosis as an opportunistic infection even at a low dose and that antibacterial agents act differently on the lung and brain lesions caused by this organism.     

Alterations of cerebral glucose metabolism indicate progress to severe morphological brain lesions in neuropsychiatric systemic lupus erythematosus

Neuropsychiatric systemic lupus erythematosus (SLE) is frequently associated with deficits in brain glucose metabolism, even if morphological imaging by magnetic resonance imaging (MRI) shows no abnormalities. In these patients it is unclear whether or not the changes of brain metabolism measured by F-18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) may progress to lesions of cerebral structure. We describe a 20-year-old woman with SLE who presented with depression, headache and impairment of memory. Initially, a cranial MRI was negative, but FDG-PET revealed significant hypometabolism in the frontal and parieto-temporo-occipital regions on both sides as well as hypermetabolism in the nuclei caudati. Within two months the patient developed an acute confusional state, seizures, visual disturbances and cranial MRI became positive showing hyperintensities at the basal ganglia and the temporo-occipital regions. Focal cerebral symptoms responded to treatment with high dose corticosteroids and brain lesions in MRI disappeared. However, a second FDG-PET showed persistent hypometabolism at frontal regions in accordance with the persistence of subclinical depression. To our knowledge, this is the first SLE case report showing that functional brain lesions visualized by FDG-PET may be a risk factor for subsequent structural brain damage seen in MRI. Thus, FDG-PET may help to verify cerebral involvement of SLE earlier than MRI.     

The number and generative capacity of human B lymphocyte progenitors, measured in vitro and in vivo, is higher in umbilical cord blood than in adult or pediatric bone marrow

We retrospectively identified opportunistic CNS infections in 655 patients who had undergone allogeneic, syngeneic or autologous BMT or PBSCT between 1990 and 1997. Twenty-seven patients (4%) developed CNS infections. All CNS infections occurred in allogeneic BMT or PBSCT patients. The most common CNS infections were toxoplasma encephalitis (74%) and cerebral aspergillosis (18%). Furthermore, we identified one patient with candida encephalitis and one patient with viral encephalitis. Overall mortality of patients with opportunistic CNS infection was 67%. There were two different groups of toxoplasma encephalitis with a different appearance on MR imaging. The first group showed edema, but no gadolinium enhancement, whereas the second group exhibited typical MRI appearances with the exception of frequent hemorrhagic transformation. The first group had a significant shorter latency between BMT and onset of CNS infection (mean 45 days vs 180 days, P = 0.02), a significant higher daily dose of corticosteroids as treatment for graft-versus-host disease (GVHD) (P = 0.01), more severe GVHD and a higher mortality (71% vs 36%). This study shows that the most common CNS infections in our patient population are toxoplasma encephalitis and cerebral aspergillosis, that there are two distinct subgroups of toxoplasma encephalitis and that CNS infections occur after allogeneic BMT only.     

Short echo-time proton magnetic resonance spectroscopy in regions of severe HIV-related diffuse white matter abnormality on MRI

The purpose of this study was to determine whether short echo-time proton magnetic resonance spectroscopy (H-MRS) could detect mobile lipid resonances attributable to myelin breakdown products in the deep cerebral white matter of patients with AIDS who have severe diffuse/patchy white matter hyperintensity on T2-weighted magnetic resonance imaging (MRI). Seven patients with AIDS and clinical HIV-associated dementia complex (HADC) and 12 male controls were studied at 1.5T using a single 8 ml voxel, gradient localised, stimulated echo acquisition mode (STEAM) spectroscopy sequence. Spectra were acquired at an echo time of 20 ms with a repetition time of 5000 ms. No spectroscopic peaks were identified at 0.9 ppm and 1.3 ppm (corresponding to lipid resonances) in 6 of the 7 patients with AIDS or in any of the controls. Lipid resonances were identified in 1 patient who had been taking anti-retroviral therapy for 8 weeks. Follow up MRI/H-MRS, performed after a further 14 weeks of anti-retroviral therapy, showed partial resolution of white matter hyperintensity and lipid resonances were not detectable. These data suggest that mobile lipids are only rarely detected by H-MRS in patients with HADC and abnormalities on MRI and that their presence may be transitory.     

Nocardia asteroides pneumonia, subcutaneous abscess and meningitis in a patient with advanced malignant lymphoma: successful treatment based on in vitro antimicrobial susceptibility.

Nocardia asteroides pneumonia, subcutaneous abscess and meningitis without brain abscesses developed in a patient with advanced non-Hodgkin's lymphoma, who had received corticosteroid therapy and cancer chemotherapy for a long time. At the time of nocardial pneumonia, profound lymphocytopenia and hypogammaglobulinemia was seen. The severely immunosuppressed condition most likely accounted for the uncommon infection, nocardiosis. The organism isolated from the sputum, subcutaneous abscess and cerebrospinal fluid was strongly resistant to cotrimoxazole, which is the recommended standard treatment, but it was susceptible to imipenem (IPM) and erythromycin (EM) in an in vitro antimicrobial susceptibility study. The patient's nocardiosis responded well to chemotherapy including IPM and EM.     

Clinical Analysis of Pulmonary Nocardiosis in Patients With Autoimmune Disease

Nocardiosis is an opportunistic infection that most commonly involves the lung; however, only a few case reports of autoimmune disease complicated by pulmonary nocardiosis exist in the literature.We conducted a retrospective analysis of 24 cases of both autoimmune disease and pulmonary nocardiosis at the Peking Union Medical College Hospital between 1990 and 2012.Fifty-two cases were hospitalized with nocardiosis, 24 of whom had at least 1 autoimmune disease before the diagnosis of pulmonary nocardiosis. The cohort patients consisted of 5 men and 19 women, with a mean age of 44.2 years. All were negative for human immunodeficiency virus. All but 1 patient had received immunosuppressants, including corticosteroids, cyclophosphamide, azathioprine, methotrexate, or hydroxychloroquine. Fever (87.5%), cough (83.3%), and sputum (79.2%) were the most common clinical manifestations. Ten cases were accompanied by subcutaneous nodules and/or cutaneous abscesses, and 4 had brain abscess. Half of them were lymphocytopenic. Thirteen of the 16 cases who underwent lymphocyte subtype analysis had decreased CD4⁺ T-cell counts. Nineteen cases had decreased serum albumin levels. Nocardia was isolated from sputum (13/24), bronchoalveolar lavage fluid (4/6), lung tissue (5/6), pleural effusions (3/5), skin or cutaneous pus (7/10), and brain tissue (1/1). The most common imaging findings were air-space opacities (83.3%), followed by nodules (62.5%), cavitations (45.8%), and masses (37.5%). Five were administered co-trimoxazole only, and the others were treated with 2 or more antibiotics. All 5 cases with skin abscesses and 2 of the 4 cases with brain abscesses were treated by surgical incision and drainage. None underwent thoracic surgery. Corticosteroid dosages were decreased in all cases, and cytotoxic agents were discontinued in some cases. Twenty-two cases recovered, and 2 died.Pulmonary nocardiosis associated with an underlying autoimmune disease showed a female predominance and presentation at younger age. Immunosuppressant therapy, lymphocytopenia, particularly low CD4⁺ T-lymphocyte counts, and low serum albumin levels may be disease susceptibility factors. Air-space opacities and nodules were the most common chest imaging features, and disseminated nocardiosis with lung and skin involvement was more common among them. Early diagnosis and anti-nocardial antibiotics with modulation of the basic immunosuppressive therapy were important for them.