Diagnostic Usefulness of Varicella Zoster Virus-Specific Immunoglobulin (Ig) A and IgG in Patients With Herpes Zoster

Background@#Whether varicella zoster virus (VZV) antibody titer could discriminate patients with herpes zoster (HZ) from healthy controls (HCs) is unclear. We evaluated the diagnostic usefulness of VZV-specific immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies in patients with confirmed HZ. @*Methods@#Study subjects comprised patients with confirmed HZ by salivary VZV DNA positivity and control age- and sex-matched HCs. Saliva was collected and concurrent blood samples were obtained on the first visit day (acute phase) and after 4 weeks (convalescent phase) from 44 HZ patients. All 44 healthy volunteers provided blood and saliva samples once. @*Results@#The median VZV IgA titers in acute-phase (5.2 mIU/mL, P < 0.001) and convalescentphase (15.8 mIU/mL, P < 0.001) serum samples from HZ patients were significantly higher than those in HCs (1.35 mIU/mL). VZV IgA positivity was detected in about 20% of acute phase serum and convalescent-phase serum of HZ patients. The median VZV IgG antibody titers of HZ patients during acute (1,471.0 mIU/mL, P < 0.001) and convalescent (4,934.7 mIU/mL, P < 0.001) phases were significantly higher than the median titer reported for HCs (591.6 mIU/mL). A four-fold or higher increase in VZV IgG antibody titer was observed in 36.4% of HZ patients. @*Conclusion@#VZV IgA positivity or four-fold or higher increase in VZV IgG antibody titers were not detected in a satisfactory proportion of HZ-infected patients. However, the titer of VZV IgA or IgG antibody particularly in convalescent-phase sera may discriminate HZ patients from HCs.

Antibiotics use patterns in end-of-life cancer patients and medical staff’s perception of antimicrobial stewardship programs

Background/Aims@#While most cancer patients with end-of-life (EOL) care receive antibiotic treatments, antibiotic use should be decided appropriately considering the benefits, side effects, resistance, and cost effects. Antimicrobial stewardship programs (ASP) are important for patients with EOL care, but there is limited study analyzing actual antibiotic use in EOL care and the perceptions of Korean medical staff. @*Methods@#Electronic medical records of 149 deceased cancer patients hospitalized in the medical hospitalist units at Asan Medical Center in Seoul from May 2019 to September 2021 were reviewed. Basic information, antibiotic use, duration, and changes were investigated. We surveyed medical staff’s perceptions of antibiotics in cancer patients with EOL. @*Results@#Of the 149 cancer patients with EOL care, 146 (98.0%) agreed with physician orders for life-sustaining treatment (POLST). In total, 143 (95.9%) received antibiotics, 110 (76.9%) received combination antibiotic treatment, and 116 (81.1%) were given antibiotics until the day of death. In a survey of 60 medical staff, 42 (70.0%) did not know about ASP, and 24 (40.0%) thought ASP was important in EOL care. Nineteen doctors (31.7%) discussed the use or discontinuation of antibiotics with patients or caregivers when writing POLST, but only 8 patients (5.6%) stopped antibiotics after POLST. @*Conclusions@#Most cancer patients with EOL care continue to receive antibiotics until just before their death. A careful approach is needed, considering the benefits and side effects of antibiotic use, and the patient’s right to self-decision. It is necessary to actively improve awareness of ASP and its importance for medical staff.

Four Times of Relapse of Plasmodium vivax Malaria Despite Primaquine Treatment in a Patient with Impaired Cytochrome P450 2D6 Function

Plasmodium vivax exhibits dormant liver-stage parasites, called hypnozoites, which can cause relapse of malaria. The only drug currently used for eliminating hypnozoites is primaquine. The antimalarial properties of primaquine are dependent on the production of oxidized metabolites by the cytochrome P450 isoenzyme 2D6 (CYP2D6). Reduced primaquine metabolism may be related to P. vivax relapses. We describe a case of 4 episodes of recurrence of vivax malaria in a patient with decreased CYP2D6 function. The patient was 52-year-old male with body weight of 52 kg. He received total gastrectomy and splenectomy 7 months before the first episode and was under chemotherapy for the gastric cancer. The first episode occurred in March 2019 and each episode had intervals of 34, 41, and 97 days, respectively. At the first and second episodes, primaquine was administered as 15 mg for 14 days. The primaquine dose was increased with 30 mg for 14 days at the third and fourth episodes. Seven gene sequences of P. vivax were analyzed and revealed totally identical for all the 4 samples. The CYP2D6 genotype was analyzed and intermediate metabolizer phenotype with decreased function was identified.

Machine-Learning-Based Approach to Differential Diagnosis in Tuberculous and Viral Meningitis / 감염과화학요법

Background@#Tuberculous meningitis (TBM) is the most severe form of tuberculosis, but differentiating between the diagnosis of TBM and viral meningitis (VM) is difficult. Thus, we have developed machine-learning modules for differentiating TBM from VM.Material and Methods: For the training data, confirmed or probable TBM and confirmed VM cases were retrospectively collected from five teaching hospitals in Korea between January 2000 - July 2018. Various machine-learning algorithms were used for training. The machinelearning algorithms were tested by the leave-one-out cross-validation. Four residents and two infectious disease specialists were tested using the summarized medical information. @*Results@#The training study comprised data from 60 patients with confirmed or probable TBM and 143 patients with confirmed VM. Older age, longer symptom duration before the visit, lower serum sodium, lower cerebrospinal fluid (CSF) glucose, higher CSF protein, and CSF adenosine deaminase were found in the TBM patients. Among the various machinelearning algorithms, the area under the curve (AUC) of the receiver operating characteristics of artificial neural network (ANN) with ImperativeImputer for matrix completion (0.85; 95% confidence interval 0.79 - 0.89) was found to be the highest. The AUC of the ANN model was statistically higher than those of all the residents (range 0.67 - 0.72, P <0.001) and an infectious disease specialist (AUC 0.76; P = 0.03). @*Conclusion@#The machine-learning techniques may play a role in differentiating between TBM and VM. Specifically, the ANN model seems to have better diagnostic performance than the non-expert clinician.

Varicella zoster virus (VZV)-specific immunity and subclinical VZV reactivation in patients with autoimmune diseases

Background/Aims@#The risk of herpes zoster (HZ) is increased in patients with autoimmune diseases (AID), probably due to immunosuppressive therapy. @*Methods@#This prospective cross-sectional study investigated varicella zoster virus (VZV)-specific immunity in relation to subclinical VZV reactivation in 48 AID patients and 48 healthy controls (HCs). We assessed humoral immunity (serum VZV immunoglobulin g [IgG], IgA, and IgM) and cell-mediated immunity (interferon-γ [IFNγ]-releasing assay) to VZV as well as salivary VZV DNA status. Subclinical VZV reactivation was confirmed by detecting VZV DNA in saliva or VZV IgM in serum in the absence of typical HZ symptoms. @*Results@#Median IgA levels were higher in the AID group than in the HC group, while VZV IgG and IgM levels were comparable between the groups. AID patients showed fewer IFNγ spot-forming cells (SFCs) upon VZV stimulation than HCs (58.2 vs. 122.0 SFCs/106 peripheral blood mononuclear cells [PBMCs], p < 0.0001). Subclinical VZV reactivation was more frequent in AID patients than in HCs (12.5% vs. 0%, p = 0.01). AID patients with VZV reactivation received prednisolone more frequently and at a higher dose than AID patients without reactivation. VZV-specific IFNγ SFCs were significantly lower in patients with VZV reactivation among AID patients (26.3 vs. 62.6 SFCs/106 PBMCs, p < 0.0001). @*Conclusions@#Results suggest that poor cellular response against VZV might cause clinical and subclinical reactivation of VZV in AID patients.

Machine-Learning-Based Approach to Differential Diagnosis in Tuberculous and Viral Meningitis / 감염과화학요법

Background@#Tuberculous meningitis (TBM) is the most severe form of tuberculosis, but differentiating between the diagnosis of TBM and viral meningitis (VM) is difficult. Thus, we have developed machine-learning modules for differentiating TBM from VM.Material and Methods: For the training data, confirmed or probable TBM and confirmed VM cases were retrospectively collected from five teaching hospitals in Korea between January 2000 - July 2018. Various machine-learning algorithms were used for training. The machinelearning algorithms were tested by the leave-one-out cross-validation. Four residents and two infectious disease specialists were tested using the summarized medical information. @*Results@#The training study comprised data from 60 patients with confirmed or probable TBM and 143 patients with confirmed VM. Older age, longer symptom duration before the visit, lower serum sodium, lower cerebrospinal fluid (CSF) glucose, higher CSF protein, and CSF adenosine deaminase were found in the TBM patients. Among the various machinelearning algorithms, the area under the curve (AUC) of the receiver operating characteristics of artificial neural network (ANN) with ImperativeImputer for matrix completion (0.85; 95% confidence interval 0.79 - 0.89) was found to be the highest. The AUC of the ANN model was statistically higher than those of all the residents (range 0.67 - 0.72, P <0.001) and an infectious disease specialist (AUC 0.76; P = 0.03). @*Conclusion@#The machine-learning techniques may play a role in differentiating between TBM and VM. Specifically, the ANN model seems to have better diagnostic performance than the non-expert clinician.

Varicella zoster virus (VZV)-specific immunity and subclinical VZV reactivation in patients with autoimmune diseases

Background/Aims@#The risk of herpes zoster (HZ) is increased in patients with autoimmune diseases (AID), probably due to immunosuppressive therapy. @*Methods@#This prospective cross-sectional study investigated varicella zoster virus (VZV)-specific immunity in relation to subclinical VZV reactivation in 48 AID patients and 48 healthy controls (HCs). We assessed humoral immunity (serum VZV immunoglobulin g [IgG], IgA, and IgM) and cell-mediated immunity (interferon-γ [IFNγ]-releasing assay) to VZV as well as salivary VZV DNA status. Subclinical VZV reactivation was confirmed by detecting VZV DNA in saliva or VZV IgM in serum in the absence of typical HZ symptoms. @*Results@#Median IgA levels were higher in the AID group than in the HC group, while VZV IgG and IgM levels were comparable between the groups. AID patients showed fewer IFNγ spot-forming cells (SFCs) upon VZV stimulation than HCs (58.2 vs. 122.0 SFCs/106 peripheral blood mononuclear cells [PBMCs], p < 0.0001). Subclinical VZV reactivation was more frequent in AID patients than in HCs (12.5% vs. 0%, p = 0.01). AID patients with VZV reactivation received prednisolone more frequently and at a higher dose than AID patients without reactivation. VZV-specific IFNγ SFCs were significantly lower in patients with VZV reactivation among AID patients (26.3 vs. 62.6 SFCs/106 PBMCs, p < 0.0001). @*Conclusions@#Results suggest that poor cellular response against VZV might cause clinical and subclinical reactivation of VZV in AID patients.

Neurocysticercosis: Clinical Characteristics and Changes from 26 Years of Experience in an University Hospital in Korea

The prevalence of human taeniasis has decreased in Korea. The stool egg positive proportion decreased from 1.9% in 1971 to 0% in 2004 in nationwide surveys. The neurocysticercosis (NCC) is also presumed to decrease. However, detailed information regarding the recent status of NCC in Korea is lacking. We retrospectively reviewed NCC cases from 1990 to 2016 at Asan Medical Center, a 2700-bed tertiary referral hospital in Korea. We identified patients based on clinical symptoms, brain imaging, pathology and serological assay. The cases were classified as parenchymal, extraparenchymal, and mixed NCC. Eighty-one patients were included in the analysis. The mean age was 54.5 years, and 79.0% were male. The number of NCC cases was highest from 1995 to 1999, and continuously decreased thereafter. Forty (49.4%) patients had parenchymal NCC, while 25 (30.9%) patients had extraparenchymal NCC, and 16 (19.8%) patients had mixed NCC. The seizure and headache were most common symptom of parenchymal NCC and extraparenchymal NCC respectively. Hydrocephalus was more common in extraparenchymal NCC, and patients with extraparenchymal NCC were more likely to require a ventriculoperitoneal shunt. Cases of NCC are decreasing accordingly with human taeniasis and lesion location was the most important determinant of clinical presentation and outcome of NCC in Korea.

Gastrocolocutaneous Fistula: An Unusual Case of Gastrostomy Tube Malfunction with Diarrhea

A gastrocolocutaneous fistula is a rare complication of percutaneous endoscopic gastrostomy (PEG). We report a case of a gastrocolocutaneous fistula presenting with intractable diarrhea and gastrostomy tube malfunction. A 62-year-old woman with a history of multiple system atrophy was referred to us because of PEG tube malfunction. Twenty days prior to presentation, the patient started developing sudden diarrhea within minutes after starting PEG feeding. Fluoroscopy revealed that the balloon of the PEG tube was located in the lumen of the transverse colon with the contrast material filling the colon. Subsequently, the PEG tube was removed and the opening of the gastric site was endoscopically closed using hemoclips. Clinicians should be aware of gastrocolocutaneous fistula as one of the complications of PEG insertion. Sudden onset of diarrhea, immediately after PEG feedings, might suggest this complication, which can be effectively treated with endoscopic closure.

A Case of Behçet's Disease Mimicking Vertebral Invasion of a Mycotic Aneurysm / 대한내과학회지

Behçet's disease is a systemic vasculitis of unknown etiology characterized by recurrent oral and genital ulcers and uveitis. The vascular involvement of Behçet's disease affects arteries, veins, and blood vessels of all sizes, and it can include venous or arterial thrombosis and arterial aneurysms. There are only a few reports of an aortic aneurysm invading a vertebral body in a patient with Behçet's disease. Here, we report the case of a 45-year-old man who was initially diagnosed with vertebral invasion of a mycotic aneurysm. He underwent vascular surgery and received empirical antibiotics, but all cultures were negative. However, he had persistent, recurrent deep vein thrombosis and elevated inflammatory markers. After reviewing the pathology, a final diagnosis of Behçet's disease was made. He was successfully treated with corticosteroids. This report presents a rare case of Behçet's disease mimicking vertebral invasion of a mycotic aneurysm.