Cryptococcal meningitis in human immunodeficiency virus (HIV)-positive and HIV-negative patients.

This study compared clinical manifestations, blood biochemistry and cerebrospinal fluid (CSF) results of HIV-positive and HIV-negative patients with cryptococcal meningitis. We collected 57 cases of cryptococcal meningitis from cytological specimens submitted to the Department of Tropical Pathology, Faculty of Tropical Medicine. Pertinent clinical data were analyzed retrospectively in 47 cases for clinical manifestations, laboratory features and outcomes of 38 HIV-positive and 9 HIV-negative patients. Headache was the most common symptom seen in all cases, of which 70.2% occurred with fever. CSF examination of both groups revealed elevated opening pressure. Increased CSF protein and depressed CSF glucose levels were seen in HIV-negative cases, which differed from HIV-positive cases, where a slight change was noted. CSF pleocytosis in HIV-positive patients was variable. Forty-eight percent of HIV-positive patients had CSF leukocyte counts below 20 cells/ mm3. None was found in the HIV-negative patients. Specific treatments with amphotericin B and fluconazole were given. Five fatal cases of cryptococcal meningitis were noted, all of which were HIV-positive. There were statistically significant differences in blood neutrophils, blood eosinophils, CSF leukocyte counts, CSF neutrophils, CSF lymphocytes, CSF glucose, and CSF total protein, in HIV-positive and HIV-negative patients (p = 0.050, p = 0.022, p = 0.002, p = 0.016, p = 0.047, p = 0.031, p = 0.009, respectively).

Cerebrospinal fluid analysis in eosinophilic meningoencephalitis.

Eosinophilic meningoencephalitis (EME) remains an important neurological disease and is widely distributed in Thailand. We analyzed the cytological specimens of 56 EME cases. Pertinent clinical data were analyzed retrospectively and correlated with the cerebrospinal fluid (CSF)analysis. Headache was the commonest symptom seen in all EME cases. History of raw or partially cooked Pila snail ingestion was elicited from most patients. There was a marked seasonal occurrence between July to January. Patients received specific treatment as supportive therapy, which included spinal taps, analgesics and corticosteroids, was adequate. No fatal cases were seen. The CSF specimens were sorted into two categories: fresh CSF and hematoxylin and eosin (H&E) stained centrifuged CSF sediment. There was a statistically significant difference between the number of eosinophils and lymphocytes of fresh CSF and the H&E stained centrifuged CSF sediment (p = 0.001 and 0.001 respectively). The CSF glucose and the number of eosinophils in both methods were significantly correlated (p = 0.000, p = 0.008 for fresh CSF and the H&E stained centrifuged CSF sediment respectively). Moreover, the number of eosinophils was statistically significant with the protein in the CSF (p = 0.013), and intracranial pressure (ICP) (p = 0.025). Higher yields of eosinophils, especially in the early course of the disease, can readily be detected in the H&E stained centrifuged CSF sediment, whereas fresh specimens were negative. Further tests may increase the sensitivity and specificity of EME diagnostic results.

Prognostic significance of skin and subcutaneous fat sequestration of parasites in severe falciparum malaria.

Intradermal blood smear, histopathologic and immunohistologic studies were performed in severe malaria (n=10) and uncomplicated malaria (n=10) patients during positive parasitemia and within 6 hours after negative parasitemia by finger prick smears. Intradermal blood smears showed asexual forms and intraleukocytic pigments when finger prick blood smears showed negative results; however intradermal blood smear did not indicate disease severity within 6 hours after negative parasitemia by finger prick. Histopathologic findings showed 15 fold higher parasitized red blood cells sequestered in vessels of subcutaneous fatty tissue in severe malaria than in uncomplicated malaria (p<0.001) and may indicate disease severity. A panel of polyclonal antibodies against cytokines applied to skin biopsies clearly detected a higher titer against tumor necrosis factor-alpha (TNFalpha) and interleukin-10 (IL-10) in dermal vessels and stratum granulosum respectively, in severe malaria compared with uncomplicated malaria. Results of the study suggest that histopathology and immunohistology of skin and subcutaneous fatty tissue may indicate prognostic severity of malaria and may be associated with focal accumulation of cytokines.

Inducible nitric oxide synthase expression is increased in the brain in fatal cerebral malaria.

AIMS: Nitric oxide (NO) has been hypothesized to play a major role in the pathogenesis of cerebral malaria caused by P. falciparum infection. NO may act as a local neuroactive mediator contributing to the coma of cerebral malaria (CM). We hypothesized that increased expression of inducible nitric oxide synthase (iNOS) may cause increased release of NO, and examined the expression and distribution of iNOS in the brain during CM. MATERIAL AND RESULTS: Brain tissues from fatal cases of cerebral malaria in Thai adults were examined using immunohistochemical staining to detect iNOS. The distribution and strength of staining was compared between 14 patients with CM, three of whom were recovering from coma, and controls. iNOS expression was found in endothelial cells, neurones, astrocytes and microglial cells in CM cases. There was also strong staining in macrophages surrounding ring haemorrhages. iNOS staining was decreased in recovering malaria cases compared to acute CM, and was low in controls. Quantification showed a significant association between the intensity and number of iNOS positive vessels with the severity of malaria related histopathological changes, although the total number of cells staining was not increased compared to recovering CM cases. CONCLUSIONS: This study indicates that an acute induction of iNOS expression occurs in the brain during CM. This occurs in a number of different cells types, and is increased in the acute phase of CM compared to cases recovering from coma. As NO may activate a number of secondary neuropathological mechanisms in the brain, including modulators of synaptic function, induction of iNOS expression in cerebral malaria may contribute to coma, seizures and death.

Opportunistic infections in the liver of HIV-infected patients in Thailand: a necropsy study.

Liver necropsy from patients infected with human immunodeficiency virus was analyzed in 117 cases. Wide ranges of opportunistic infections were recorded in 47%. Cryptococcosis (21.4%) was the most outstanding infection, followed by tuberculosis (16.2%), cytomegalovirus (5.1%) and penicillosis (3.4%). Non-specific alterations of the liver tissues included fatty steatosis (49.6%), fibrosis (55.6%), portal inflammation and reactive hepatitis. Cases of chronic active and chronic passive hepatitis and one case of hepatocellular carcinoma were reported. In the infected liver, predominant pathological changes included granuloma and spotty necrosis, which were attributed to tuberculous hepatitis. Infection with Cryptococcus usually showed no associated pathological change. The sensitivity for the clinical diagnosis of Cryptococcus was 88.8% and specificity was 91.7%. For tuberculosis, sensitivity was 20% and specificity was 67.9%.

Cytokines associated with pathology in the brain tissue of fatal malaria.

Cytoadherence of Plasmodium falciparum-infected erythrocytes to the brain microvascular endothelial cells is believed to be an important cause of circulatory blockage in cerebral malaria. Cytokines released during acute infection may activate brain endothelial cells leading to increased binding of infected erythrocytes in the brain and reduced cerebral blood flow. This effect may be direct and more potent with the tissue-localized cytokines in the brain. In order to establish this relationship, brain tissues of cerebral and noncerebral malaria were compared. The most prominent histopathologic changes in the brain included edema, neuronal degeneration, ring hemorrhage, and percentage of parasitized erythrocytes sequestration were observed in cerebral malaria. Immunohistochemical staining of the brain sections demonstrated that tissue-localized TNF-alpha, IFN-gamma, IL-I1B, and IL-10 were associated with the histopathology. However, IL-4 was the only cytokine presented at moderate level in the brain tissue of noncerebral malaria which histopathology was the least. No tissue-localized cytokine was observed in the brain of P. vivax infection or of the car accident control cases.

Cytomegalovirus and Cryptosporidium infections in AIDS: a necropsy study.

A case of coinfection of cytomegalovirus (CMV) and Cryptosporidium in an AIDS patient is reported. Chronic diarrhea was the presenting symptom. Etiologic agents were diagnosed only at postmortem evaluation. CMV intranuclear inclusions were seen in the terminal ileum, colon and vermiform appendix. Cryptosporidium oocysts were also present in the intestinal brush border of the colon. Improvement of diagnostic procedures such as colonic biopsy and the use of appropriate staining procedure for AIDS patients with diarrhea can help identify the cause of illness.

Opportunistic protozoa in stool samples from HIV-infected patients.

A retrospective study of stool samples of HIV-infected patients from January 1994 to December 1995 submitted to the Department of Tropical Pathology was analyzed. There were twenty-two cases, all of which presented with chronic diarrhea. Result showed that 50% were infected with protozoa. These include Microsporidium (27.27%), Cryptosporidium (9.09%), Isospora belli (4.54%) and Giardia intestinalis cysts (9.09%). Other infections were Candida sp, Strongyloides stercoralis larva and Opisthorchis viverrini ova. The data stress the importance of opportunistic protozoa in the HIV-infected patients. Awareness of their existence of the diseases is important areas with increasing number of HIV-infected patients for early detection and proper treatment.

Electron-microscopic examination of Rickettsia tsutsugamushi-infected human liver.

A 33 year-old Thai woman was diagnosed with scrub typhus infection according to clinical symptoms, eschar lesions compatible with the disease, and specific antibody to Rickettsia tsutsugamushi detected by indirect immunoperoxidase. Percutaneous transhepatic needle biopsies were taken before and 7 days after treatment with tetracycline to study the pathology of the liver. The liver tissue was evaluated by light microscopy, using H & E and Pinkerton's stains, and by transmission electron microscopy (TEM). Before treatment it showed reactive hepatitis. Rickettsia organisms within the hepatocytes and sinusoids detected by Pinkerton's stain appeared as tiny bright-red organisms. By TEM, the rod-shaped double-membrane Rickettsiae appeared intact in the cytoplasm of Kupffer's cells and hepatocytes. After tetracycline treatment, moderate levels of acidophilic and ballooning liver cells were observed. The degree of cytoplasmic organelle damage varied, including fatty metamorphosis, depletion of glycogen granules, loss of the mitochondrial cristae, dilatation of endoplasmic reticulum and cytoplasmic vacuolation. Rickettsia organisms cannot be visualized by Pinkerton's stain but were detected by TEM, in markedly vacuolated hepatocytes, in congested sinusoids and in Kupffer's cells. Intranuclear Rickettsia were discovered in the endothelial nucleus, showing various degrees of injury. Some were mildly degenerated, while others exhibited clumping of nucleoprotein at the cytoplasm periphery and large vacuolation centrally. Many indented organisms were found, and binary fission during Rickettsiae multiplication was always affected. Electron-microscopic examination of hepatic injury associated with scrub typhus is rare. This is the first ultrastructural localization of Rickettsiae in the infected human liver.

Imported cutaneous leishmaniasis in Thailand.

Eleven cases of imported cutaneous leishmaniasis are described based on clinical features such as sex, age, occupation, country visited prior to consultation, sites and numbers of lesions, duration of illness, treatment and outcomes. Ketoconazole was shown to be effective against imported cutaneous leishmaniasis. With the increasing numbers of cutaneous leishmaniasis due to exchange workers going to the endemic areas and the presence of vectors in some localities in Thailand, primary transmission of the disease in this country is possible if feeding habits of the vectors change.

Microsporidium: modified technique for light microscopic diagnosis.

Microsporiodosis caused by Enterocytozoon bieneusi is one of the opportunistic infections in HIV positive patients with chronic diarrhea. The organism is difficult to diagnose because of its small size, previously the diagnosis of this infection relied on identification of the organism under electron microscope. Until recently, the spores of this organism in stool specimens could be seen under light microscope by using various staining techniques. In this study, the modified trichrome staining technique was used to identify microsporidia spores with characteristic red belt-like stripes. Less time and less reagent are required by this modified technique than the conventional method.

Monoclonal antibody-based immunohistochemical demonstration of Entamoeba histolytica in liver tissues of experimentally infected hamster (Mesocricetus auratus).

Histopathological changes and the presence of Entamoeba histolytica trophozoites was sequentially followed after intrahepatic inoculation of the parasites in 42 hamsters, 35 of which received no treatment whereas the remaining seven were treated with metronidazole. The liver tissues were examined for amoebic trophozoites by a monoclonal antibody (mAb)-based immunofluorescence assay (IFA), a mAb-based immunoperoxidase (IPx) and H & E staining. The number of hamsters developing abscesses was increased with time and was highest on day 30. Cellular infiltration with inflammatory cells and glycogen depletion were observed as early as day 5, followed thereafter by more intense inflammation of portal canals, periportal fibrosis, bile duct proliferation and hepatocyte degeneration. In 7 metronidazole-treated hamsters, no obvious pathological damage was seen. In a group of seven hamsters each, both IPx and IFA were positive in 3, 3, 4, 5 and 4 hamsters and in 3, 4, 3, 3 and 5 hamsters on days 5, 10, 15, 20 and 30, respectively. In 18 control hamsters, IPx, IFA and H & E were all negative. If the result from H & E was used as a gold standard, agreement between H & E and IFA and H & E and IPx were 91.4%, and 88.6%, respectively. Sensitivity and specificity were 93.8% and 89.5%, respectively for IFA, and 93.8% and 84.2%, respectively for IPx.

Dyspepsia in acute falciparum malaria: a clinico-pathological correlation.

Gastrointestinal symptoms are common in acute falciparum malaria. Dyspepsia often occurs in such patients and sometimes it is exceptionally severe. However, the pathogenesis of the dyspeptic symptoms in malaria has not been clearly defined. Upper gastrointestinal endoscopy was performed in 40 patients with acute falciparum malaria in order to correlate the dyspeptic symptoms with the macroscopic (endoscopic) and microscopic (histologic) pathology of stomach and duodenum. The patients were divided into a dyspeptic group (n = 20, male/female ratio = 17/3, age range 18-50 years, mean age = 28.85 + 9.14 years), and a non-dyspeptic group (n = 20, male/female ratio = 16/4, age range 15-47, mean age 26.05 + 9.98 years). The findings revealed that dyspepsia correlated with topographic endoscopic pangastritis (p = 0.0014), the category of endoscopic antral gastritis (p = 0.013), and the histologic severity of antral gastritis (p = 0.0434). The results suggested that gastritis should be considered in acute falciparum malaria patients presenting with dyspepsia.

Microvascular sequestration of parasitized erythrocytes in human falciparum malaria: a pathological study.

Thirty-nine falciparum malaria autopsy cases from the Hospital for Tropical Diseases, Mahidol University, Bangkok, Thailand were divided into two groups that had had either cerebral malaria (CM) or non-cerebral malaria (NCM). We then studied significant pathological differences between these groups in order to investigate the correlation between parasitized erythrocyte (PRBC) sequestration in small blood vessels in the brain, heart, lungs and small intestines. We found that the percentage of PRBC sequestration in the organs which we studied was higher in the CM patients than in the NCM patients. The difference of PRBC sequestration among the organs of two groups was significant (P less than 0.05). In the CM group, the average percentage of PRBC sequestration in the brain was significantly higher than in the heart, lungs and small intestines (P less than 0.05). No statistically significant difference was found between PRBC sequestration in the brains, hearts, lungs and small intestines in the NCM group (P greater than 0.05). Our study indicates that severity of malaria in the CM patients depends on PRBC sequestration, especially in the brain. A combination of functional disturbances of the other organs, in addition to the cerebral pathology, may augment the severity of the disease.

Human cerebral malaria in Thailand: a clinico-pathological correlation.

Based on the cerebral malaria coma scale, 39 falciparum malaria autopsy cases from the Hospital for Tropical Diseases, Mahidol University, Bangkok, Thailand were divided into two groups of patients that had either cerebral malaria or non-cerebral malaria. We then studied significant pathological differences, such as parasitized erythrocyte (PRBC) sequestration, ring hemorrhages and cerebral edema, between these two groups in order to investigate the correlation between the clinical coma scale and pathological findings. Patients with a coma grade of 2 and higher were designated as having cerebral malaria, and had erythrocyte PRBC sequestration in cerebral microvessels. Ninety four percent (94%) of cerebral microvessels showed PRBC sequestration when quantitatively analyzed. On the other hand, only 13% of cerebral microvessels showed sequestration in non-cerebral malaria patients with a coma grade of 1 and lower, although some degree of PRBC sequestration was found in 50% of these patients. Our study, therefore, clearly demonstrated that the degree of the PRBC sequestration in cerebral microvessels appeared to correlate closely with the clinical coma scale.

Human pathology of Opisthorchis viverrini infection: a comparison of adults and children.

The pathology of human opisthorchiasis in 22 adults (20 to 68 years) and 7 children (7 to 15 years) at autopsy is described. The changes of the liver in adults and children are similar and are summarized as follows: Enlargement of the liver was a common finding. Pericholangitis was observed in most cases. The pathology was confined to the large and medium-sized bile ducts where the flukes inhabited. The small interlobular bile ducts had minimal or unremarkable changes. Dilatation of the bile ducts with hyperplasia, desquamation and proliferation of the bile duct epithelial cells, glandular formation and fibrous connective tissue infiltration of the walls were the most common features. The pathological changes were well established within 7 to 15 years. Dilatation of the gallbladder, chronic cholecystitis and carcinoma were found only in adults. Eight of ten cases were cholangiocarcinoma and two were hepatocellular carcinoma.

Subcutaneous phycomycosis mimics elephantiasis.

A case of subcutaneous phycomycosis involving the right thigh for 1 year duration which mimic elephantiasis was reported in a 21-year-old military man. An initial diagnosis was that of a subcutaneous tissue lesion attributed to parasitic manifestation but turned out to be that of subcutaneous fungal infection both clinically and histologically. The lesion was successfully treated with cotrimoxazole for a period of one month, and followed up for 4 1/2 months with complete cure.