Highly Prevalent Hyperuricaemia is Associated with Adverse Clinical Outcomes Among Ghanaian Stroke Patients: An Observational Prospective Study.

BACKGROUND: Although a direct causal relationship between hyperuricaemia and stroke continues to be debated, strong associations between serum uric acid (SUA) and cerebrovascular disease exist. Very few studies have been conducted to evaluate the frequency and association between this potentially modifiable biomarker of vascular risk and stroke in sub-Saharan Africa. Therefore the aim of this study was to examine the association between hyperuricaemia and the traditional risk factors and the outcomes of stroke in Ghanaian patients. METHODS: In this prospective observational study, 147 patients presenting with stroke at a tertiary referral centre in Ghana were consecutively recruited. Patients were screened for vascular risk factors and SUA concentrations measured after an overnight fast. Associations between hyperuricaemia and stroke outcomes were analysed using Kaplan-Meier and Cox proportional hazards regression analysis. RESULTS: The frequency of hyperuricaemia among Ghanaian stroke patients was 46.3%. Non-significant associations were observed between hyperuricaemia and the traditional risk factors of stroke. SUA concentration was positively correlated with stroke severity and associated with early mortality after an acute stroke with unadjusted hazards ratio of 2.3 (1.4 - 4.2, p=0.001). A potent and independent dose-response association between increasing SUA concentration and hazard of mortality was found on Cox proportional hazards regression, aHR (95% CI) of 1.65 (1.14-2.39), p=0.009 for each 100µmol/l increase in SUA. CONCLUSIONS: Hyperuricaemia is highly frequent and associated with adverse functional outcomes among Ghanaian stroke patients. Further studies are warranted to determine whether reducing SUA levels after a stroke would be beneficial within our setting.

The profile of risk factors and in-patient outcomes of stroke in Kumasi, Ghana.

BACKGROUND: Stroke is an emerging public health challenge in Ghana requiring urgent attention for its control. Because some of the risk factors for stroke are modifiable, characterisation of these risk factors in the Ghanaian population as well as outcomes of stroke are urgently needed to guide policy for non-communicable diseases. We therefore conducted this study to evaluate the frequencies of the traditional risk factors and outcomes of stroke at the main tertiary referral centre in the middle belt of Ghana in a prospective observational study. METHODS AND RESULTS: Patients with a clinical diagnosis of stroke were consecutively recruited and vascular risk factors were assessed as well as markers of severity of stroke and in-patient treatment outcomes. 265 patients were recruited, 56.6% were females and mean ± SD age of 64.6 ± 14.54 years. 85%, 73% and 58% of patients had systemic arterial hypertension, physical inactivity and obesity respectively as common risk factors. We identified that patients with stroke had a median of 3 traditional risk factors, were unaware of the presence of these risk factors or were poorly controlled if known. Stroke was associated with a high in-patient case fatality rate of 43% principally among patients with haemorrhagic stroke. CONCLUSIONS: Our findings indicate that urgent concerted efforts are required to improve public awareness and management of the prevailing risk factors of stroke in Ghana.

The role of bone marrow aspirate and trephine samples in haematological diagnoses in patients referred to a teaching hospital in Ghana.

INTRODUCTION AND METHODS: A bone marrow examination had been requested by the referring clinician in over half of the 250 patients referred to the haematology clinic at Konfo Anokye Teaching Hospital (KATH) between 1988 and 1998 for investigations for various haematological disorders. Although a full blood count and a peripheral blood film can go a long way to resolve some of these diagnostic challenges faced by doctors in the districts, this information was generally not provided in the referral letter. After careful selection, 80 patients actually underwent a bone marrow examination. The result of the full blood count and peripheral film were available before bone marrow sampling was done. RESULTS: Lymphoproliferative disorders were the most common diseases that caused infiltration of the bone marrow. 27.5% of lymphomas were diagnosed on morphological examination of the bone marrow as high grade B cell NHL, 13.75% had tropical splenic lymphoma, 10% had chronic lymphocytic leukaemia (CLL) and 5% had disseminated high grade T cell lymphoma and 2.5% had Adult T cell Leukaemia Lymphoma (ATLL). Other disorders diagnosed after bone marrow examination include myelodysplastic syndrome (MDS), aplastic anaemia, megaloblastic anaemia and myelofibrosis. Only 8.75% of these patients had a normal bone marrow. CONCLUSIONS: This study has demonstrated the complexity of using bone marrow examination in clinical diagnosis and emphasizes the need for referring clinicians to consider involving specialist input in difficult haematological cases before requesting bone marrow examination for their patients.

Outcomes of starting first-line antiretroviral therapy in hepatitis B virus/HIV-coinfected patients in Ghana.

OBJECTIVES: HIV/hepatitis B virus (HBV) coinfection is common in Ghana, where first-line antiretroviral therapy (ART) comprises lamivudine with zidovudine or stavudine and nevirapine or efavirenz. Little is known about ART outcomes in the context of coinfection. This study evaluated outcomes of ART among HIV/HBV-coinfected Ghanaians, focusing on locally available parameters. PATIENTS AND METHODS: An observational study comparing clinical and virological outcomes in HIV-infected individuals who were either hepatitis B surface antigen (HBsAg) positive or HBsAg negative was conducted over 36 months. Clinical events, hepatic transaminases, CD4 count and body mass index (BMI) were evaluated among 143 HBsAg-positive and 228 HBsAg-negative patients. In a random subset of HBsAg-positive patients, HBV-DNA levels and polymerase sequences were analysed. RESULTS: Comparing HBsAg-positive and HBsAg-negative patients, 44/143 (30.8%) and 83/228 (36.4%) defaulted follow-up, 15/143 (10.5%) and 30/228 (13.2%) experienced a new clinical event, and 8/143 (5.6%) and 11/228 (4.8%) discontinued their initial regimen, respectively. Transaminase levels were higher in HBsAg-positive patients, although elevations were low grade. HBV coinfection was associated with an adjusted 2.04 (95% CI 0.59-3.49) cells/mm(3)/month smaller CD4 cell increase; there was no significant effect on BMI changes. After a median of 9 months of ART, 64/66 (97.0%) patients showed detectable HBV-DNA (median 3.3 log(10) IU/mL; IQR 2.6-6.2); 12/53 (22.6%) of these showed lamivudine-associated resistance mutations. CONCLUSIONS: HIV/HBV-coinfected Ghanaians tolerated first-line ART well, but experienced blunted CD4 cell responses. There was evidence of ongoing HBV replication, mild but persistent transaminase elevations and emerging lamivudine resistance in a proportion of treated patients, indicating the potential for progressive liver damage.

Umbilical-cord blood for transfusion in children with severe anaemia in under-resourced countries.

Shortage of blood for transfusion contributes substantially to mortality of children with severe anaemia in sub-Saharan Africa. Umbilical-cord blood could be an additional and readily available source of blood. We aimed to show whether it is possible to gather cord blood in a busy Ghanaian labour ward. Mean volume of each blood sample obtained from the umbilical cord was 85 mL (SD 28.0). This amount of blood is sufficient to raise the haemoglobin concentrations of 28 (21%) of 131 children needing transfusions in the same hospital, by 30 g/L. Further work is needed to improve the sterility of cord blood and to establish the resource and logistical implications of scaling-up for sub-Saharan Africa transfusion services.

B-lymphotropic viruses in a novel tropical splenic lymphoma.

Peripheral blood from patients with a novel tropical splenic lymphoma, characterized by splenomegaly and circulating naïve CD5-negative villous B lymphocytes, has been screened for evidence of an association with the B-lymphotropic viruses, Epstein--Barr virus (EBV), hepatitis C virus (HCV) and human herpesvirus 8 (HHV8). No increased prevalence of EBV, HCV and HHV8 was demonstrated using serological and molecular techniques, compared with a geographical, age-matched control group. However, lymphoma patients had markedly raised EBV antibody levels without a concomitant increase in the rate of detection of viral genomes in the peripheral blood. This phenomenon also occurred in patients with hyper-reactive malarial splenomegaly, a condition that occurs in the same geographical area and that is clinically indistinguishable from tropical splenic lymphoma, adding further weight to the suggestion that there may be an aetiological association between these two disorders.

Bioavailability and preliminary clinical efficacy of intrarectal artesunate in Ghanaian children with moderate malaria.

We report the first detailed pharmacokinetic assessment of intrarectal (i.r.) artesunate (ARS) in African children. Artesunate was given intravenously (i.v.; 2.4 mg/kg of body weight) and i.r. (10 or 20 mg/kg formulated as 50- or 200-mg suppositories [Rectocaps]) in a crossover study design to 34 Ghanaian children with moderate falciparum malaria. The median relative bioavailability of dihydroartemisinin (DHA), the active antimalarial metabolite of ARS, was higher in the low-dose i.r. group (10 mg/kg) than in the high-dose i.r. group (20 mg/kg) (58 versus 23%; P = 0.018). There was wide interpatient variation in the area under the concentration-time curve after i.r. ARS administration (up to 9-fold in the high-dose group and 20-fold in the low-dose group). i.r. administered ARS was more rapidly absorbed in the low-dose group than the high-dose group (median [range] absorption half-lives, 0.7 h [0.3 to 1.24 h] versus 1.1 h [0.6 to 2.7 h] [P = 0.023]. i.r. administered ARS was eliminated with a median (range) half-life of 0.8 h (0.4 to 2.7 h) (low-dose group and 0.9 h (0.1 to 2.5 h) (high-dose group) (P = 1). The fractional clearances of DHA were 3.9, 2.6, and 1.5 liters/kg/h for the 20-mg/kg, 10-mg/kg and i.v. groups, respectively (P = 0.001 and P = 0.06 for the high-and low-dose i.r. groups compared with the i.v. groups, respectively). The median volumes of distribution for DHA were 1.5 liters kg (20 mg/kg, i.r. group), 1.8 liters/kg (10 mg/kg, i.r. group), and 0.6 liters/kg (i.v. group) (P < 0.05 for both i.r. groups compared with the i.v. group). Parasite clearance kinetics were comparable in all treatment groups. i.r. administered ARS may be a useful alternative to parenterally administered ARS in the management of moderate childhood malaria and should be studied further.

Glucose and lactate kinetics in children with severe malaria.

Children with severe malaria often present with lactic acidosis and hypoglycemia. Although both complications independently predict mortality, mechanisms underlying their development are poorly understood. To study these metabolic derangements we sequentially allocated 21 children with falciparum malaria and capillary lactate concentrations of 5 mmol/L or more to receive either quinine or artesunate as antimalarial therapy, and dichloroacetate or saline placebo for lactic acidosis. We then administered a primed infusion (90 min) of L-[3-13C1]sodium lactate and D-[6,6-D2]glucose to determine the kinetics of these substrates. The mean (SD) glucose disposal rate in all patients was 56 (16) micromol/kg x min, and the geometric mean (range) lactate disposal rate was 100 (66-177) micromol/kg x min. Glucose and lactate disposal rates were positively correlated (r = 0.62; P = 0.005). Artesunate was associated with faster parasite clearance, lower insulin/glucose ratios, and higher glucose disposal rates than quinine. Lactate disposal was positively correlated with plasma lactate concentrations (r = 0.66; P = 0.002) and time to recovery from coma (r = 0.82; P < 0.001; n = 15). Basal lactate disposal rates increased with dichloroacetate treatment. Elevated glucose turnover in severe malaria mainly results from enhanced anaerobic glycolysis. Quinine differs from artesunate in its effects on glucose kinetics. Increased lactate production is the most important determinant of lactic acidosis.

VH gene sequences from a novel tropical splenic lymphoma reveal a naive B cell as the cell of origin.

The prevalence of malaria and other infections in tropical Africa provides a setting for the emergence of B-cell tumours distinct from that in Western countries. Attempts to draw comparisons with Western lymphomas have led to difficulties, with so-called African chronic lymphocytic leukaemia (CLL) having a different pattern of incidence from Western CLL. Splenomegaly is common in African CLL, and this has posed diagnostic problems in differentiating the tumour from malaria-associated hyper-reactive malarial splenomegaly (HMS). One feature of the splenomegalic form of African CLL is that the tumour cells often possess short but fine cytoplasmic projections reminiscent of those observed in Western splenic lymphoma with villous lymphocytes (SLVL). Analysis of Ig VH genes both facilitates discrimination between clonal B-cell tumours and HMS, and reveals the differentiation status of the cell of origin. This study indicated that VH genes of nine cases of clonal splenic B-cell tumours with villous lymphocytes from Ghana were relatively unmutated, consistent with an origin from a naive B cell. These features differ from SLVL which arises from a post-follicular antigen-selected B cell. One possibility is that these splenic B-cell tumours derive from a splenic T-independent B cell, with malaria infection as a potential influence.

Plasma glutamine levels and falciparum malaria.

Glutamine deficiency is associated with increased rates of sepsis and mortality, which can be prevented by glutamine supplementation. Changes in glutamine concentration were examined in Ghanaian children with acute falciparum malaria and control cases. The mean (SD) plasma glutamine concentration was lower in patients with acute malaria (401 (82) mumol/L, n = 50) than in control patients (623 (67) mumol/L, n = 7; P < 0.001). Plasma glutamine concentrations all rose in convalescence. The mean (SD) increase in plasma glutamine was 202 (123) mumol/L (n = 18; P < 0.001) compared with acute infection. We conclude that acute falciparum malaria is associated with large decreases in plasma glutamine and these falls may increase susceptibility to sepsis and dyserythropoeisis.

Splenic lymphoma with villous lymphocytes should be included in the differential diagnosis of massive splenomegaly.

AIM: To distinguish between patients with reactive lymphocytosis and those with malignant lymphoid proliferations, with particular reference to hyper-reactive malarial splenomegaly and splenic lymphoma with villous lymphocytes. PATIENTS: Forty-four patients, residents of the Ashanti region of Ghana that is hyperendemic for Plasmodium falciparum malaria, were studied. All patients had splenomegaly greater than 10 cm. They were given proguanil 100 mg/day for a minimum of 6 months. Lymphocyte surface phenotypes were studied on the peripheral blood smears, immunoglobulin gene rearrangement by the Southern blot technique, serum IgM concentration using the Nor-Partigen-IgM kit, and serum paraprotein concentration by electrophoresis. RESULTS: Based on the response to proguanil, the patients were categorized into good respondents, partial respondents, and non respondents. Peripheral blood lymphocytes exceeded 30% in 19, and villous lymphocytes were less than 30% in 25 patients. CONCLUSION: Splenic lymphoma with villous lymphocytes may be difficult to differentiate from the African variant of chronic lymphocytic leukemia which is associated with splenomegaly and from hyperreactive malarial splenomegaly with lymphocytosis. In West Africa, a peripheral blood lymphocyte count greater than 10 x 109/L, with more than 30% of villous lymphocytes and failure of splenic regression with anti-malarial therapy suggest a diagnosis of splenic lymphoma with villous lymphocytes.

Serological similarities between hyperreactive malarial splenomegaly and splenic lymphoma in west Africa.

In West Africa hyperreactive malarial splenomegaly (HMS) and splenic lymphoma with villous lymphocytes (SLVL) are demographically and clinically indistinguishable. Determination of lymphocyte clonality is needed to differentiate clearly between these 2 disorders. To obtain evidence to support our hypothesis that HMS and SLVL are aetiologically related we studied the serological profile of malaria-related antibodies in HMS and SLVL in West Africa. We found that in SLVL total immunoglobulin M and antimalarial antibody levels were markedly raised, a combination which is characteristic of HMS. These findings strongly support a developmental relationship between HMS and SLVL in tropical Africa and implicate malaria in this process.

Plasma nitrogen oxides and blood lactate concentrations in Ghanaian children with malaria.

Nitric oxide is an important host defence molecule as well as being a mediator in many pathophysiological processes. To investigate its role in severe malaria, we measured plasma nitrate and nitrite concentrations in 70 children with malaria (54 with severe malaria) and 48 control subjects (33 with medical conditions and 15 surgical patients). We related these measurements to plasma lactate concentrations, an established marker of disease severity in malaria. Plasma lactate levels were significantly elevated in patients with deep coma (P = 0.0007) and those with a fatal outcome, but mean nitrogen oxide concentrations were not significantly different in the 2 outcome categories and were not related to depth of coma (P > 0.5). In patients whose cerebrospinal fluid (CSF) was examined, lactate concentrations were elevated in fatal cases (geometric mean 8.2 mmol/L, n = 5) compared with survivors (3.4 mmol/L, n = 13; P = 0.032); corresponding CSF nitrogen oxide concentrations were 10.7 microM in fatal cases compared with 12.5 microM in survivors (P = 0.5). Plasma nitrogen oxide concentrations were negatively correlated with admission parasitaemia (r = -0.41, n = 70; P < 0.0001). In our population, elevations of plasma lactate, but not nitrite or nitrate, reflected disease severity in malaria.

Circulating villous lymphocytes--a link between hyperreactive malarial splenomegaly and splenic lymphoma.

Significant numbers of villous lymphocytes were noted in the blood of patients with a clinical diagnosis of hyperreactive malarial splenomegaly (HMS) in Ghana. Demographic and haematological data were recorded from 22 patients with massive splenomegaly. Additional investigations included lymphocyte immunophenotyping, protein electrophoresis and immunoglobulin gene rearrangements. Although all patients had over 30% villous lymphocytes and no leucocytosis, 7 had no evidence of a monoclonal disorder. Immunophenotyping and the presence of monoclonal lymphocytes identified 3 further patients with B-cell splenic lymphoma with villous lymphocytes (B-SLVL). HMS and SLVL co-existed in the same, predominantly female, patient population and were indistinguishable except by molecular analysis of lymphocytes. The discovery of the uncommon villous lymphocytes in both non-malignant and malignant disorders in the same geographical area suggested that HMS and SLVL are pathophysiologically related. In Caucasians with SLVL the malignant cells arise from B-cells that have undergone antigen selection. We postulate that the excessive proliferation of polyclonal B-lymphocytes, driven by frequent exposure to malaria, predisposes to the emergence of a malignant lymphoma, B-SLVL, in tropical West Africa.

How to hone haematology skills.

In Ghana a pilot programme for the continuing education of haematology laboratory technicians has produced marked improvements in skills and has led to the development of a five-year strategy for national in-service training. The factors responsible for the success of the programme are outlined below.

Chronic malaria and splenic lymphoma: clues to understanding lymphoma evolution.

In west Africa, splenic lymphoma with villous lymphocytes and hyper-reactive malarial splenomegaly have many clinical and immunological features in common suggesting an aetiopathological link. We hypothesize that in hyper-reactive malarial splenomegaly the dysregulated immune response to repeated malaria infections results in a stimulated, proliferating pool of B cells in which perturbation of cell growth and apoptosis by environmental and other factors promotes the development of SLVL. In Africa these factors are likely to include infectious agents several of which have already been associated with B-cell non-Hodgkin's lymphomas.