Profile of human papillomavirus genotypes in breast and oesophageal cancer patients in Pretoria, South Africa

BACKGROUND

The association between human papillomavirus (HPV) and cervical cancer is well established, and cervical cancer can be prevented through HPV vaccination. Little has been reported on the association between HPV and breast carcinoma (BC) or oesophageal squamous cell carcinoma (OSCC) in Africa. It is possible that use of appropriate HPV vaccines against genotypes responsible for these cancers may also prevent their development.

OBJECTIVES

To investigate HPV genotype prevalence in BC and OSCC patients in Pretoria, South Africa (SA).

METHODS

A retrospective cross-sectional study of BC and OSCC patients managed at Steve Biko Academic Hospital from 2015 to 2019 was undertaken. Patient medical records were analysed, and DNA was extracted from their archived pathology material and amplified by polymerase chain reaction before hybridisation for HPV genotypes.

RESULTS

There were 101 patients with BC and 50 with OSCC. The prevalence of HPV infection in BC patients was 77.2%, with 35.6% high- risk (HR) genotypes, and that in OSCC patients 90.0%, with 56.0% HR genotypes. The most prevalent HPV genotypes (>20% each) were HPV 16, 70 and 51 for BC and HPV 51, 70, 16 and 82 for OSCC, with 31.7% and 60.0% of patients, respectively, having co-infection with ≥2 genotypes.

CONCLUSION

The high prevalence of infection with multiple HPV genotypes in BC and OSCC patients, with HPV 16, 51, 70, 35 and 82 the most common genotypes in these cancers, warrants expansion of the current SA bivalent HPV 16/18 vaccine for girls to include boys, and inclusion of HPV 51, 70, 35 and 82, in order to prevent BC and OSCC as well as cervical cancer.

Osteoporosis, Rather Than Sarcopenia, Is the Predominant Musculoskeletal Disease in a Rural South African Community Where Human Immunodeficiency Virus Prevalence Is High: A Cross-Sectional Study

The rollout of antiretroviral therapy globally has increased life expectancy across Southern Africa, where 20.6 million people now live with human immunodeficiency virus (HIV). We aimed to determine the prevalence of age-related osteoporosis and sarcopenia, and investigate the association between HIV, bone mineral density (BMD), muscle strength and lean mass, and gait speed. A cross-sectional community-based study of individuals aged 20-80 years in rural South Africa collected demographic and clinical data, including HIV status, grip strength, gait speed, body composition, and BMD. Sarcopenia was defined by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) guidelines, and osteoporosis as BMD T-score ≤ -2.5 (if age ≥50 years). The mean ± standard deviation (SD) age of 805 black South African participants was 44.6 ± 14.8 years, 547 (68.2%) were female; 34 (13.2%) were men, and 129 (23.6%) women had HIV, with 88% overall taking anti-retroviral therapy. A femoral neck T-score ≤ -2.5, seen in four of 95 (4.2%) men and 39 of 201 (19.4%) women age ≥50 years, was more common in women with than without HIV (13/35 [37.1%] versus 26/166 [15.7%]; p = 0.003). Although no participant had confirmed sarcopenia, probable sarcopenia affected more men than women (30/258 [11.6%] versus 24/547 [4.4%]; p = .001]. Although appendicular lean mass (ALM)/height2 index was lower in both men and women with HIV, there were no differences in grip strength, gait speed, or probable sarcopenia by HIV status. Older age, female sex, lower ALM/height2 index, slower gait speed, and HIV infection were all independently associated with lower femoral neck BMD. In conclusion, osteoporosis rather than sarcopenia is the common musculoskeletal disease of aging in rural South Africa; older women with HIV may experience greater bone losses than women without HIV. Findings raise concerns over future fracture risk in Southern Africa, where HIV clinics should consider routine bone health assessment, particularly in aging women. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Rat bite injuries in children: description of a novel classification

PURPOSE

Rats are common intruders into human settlements. Apart from their role as disease vectors, they can also cause bite injuries. We describe the clinical course of a series of children with rat bites, and characterise the injures.

METHODS

A retrospective review of hospital records of children admitted for rat bites in a large regional hospital was undertaken. The demographics, wound characteristics, treatment given and clinical outcome of the patients are described.

RESULTS

Fifty-nine children, with a mean age of 3.7 years, were admitted for rat bites. Three distinct types of wounds were treated: superficial scratches (Type I), deeper bites often with infection and ulceration (Type II) and full-thickness with loss of skin or underlying soft tissues (Type III). Few wounds displayed signs of inflammation. Only some Type II injuries required urgent local surgery in the form of drainage and debridement. Type III wounds required a skin graft. All patients recovered.

CONCLUSION

We suggest that treatment of rat bites should be based on the wound type. Most patients do not require hospital admission or antibiotic treatment. Treatment should be mostly conservative wound care management. Surgery is only indicated for drainage of pus, debridement, skin graft or rarely reconstruction.

Human immunodeficiency virus infection is associated with a differential increase in cytokine response and increased risk of perforation in acute appendicitis

HIV infection causes increased perforation rate in acute appendicitis and alters cytokine profile resulting in increased pro-inflammatory cytokines in serum but decreased in peritoneal fluid. It is also accompanied by increased anti-inflammatory cytokines.

Leucocyte count and C-reactive protein cannot be relied upon in the diagnosis of acute appendicitis in HIV-infected patients

BACKGROUND

South Africa has the highest prevalence of human immunodeficiency virus (HIV) infection in the world, and is commonly found in association with appendicitis. Atypical presentation of appendicitis in the presence of HIV infection makes clinical diagnosis of appendicitis unreliable, and inflammatory markers are commonly used as adjuncts. The aim of this study was ascertain the value of inflammatory markers in the diagnosis of appendicitis in patients with and without HIV infection.

METHODS

Patients with acute appendicitis were studied and divided into HIV-infected and HIV-uninfected groups. Symptoms, and systemic and local signs were recorded. Appendiceal pathology was classified as simple or as complicated by abscess, phlegmon or perforation. Total white cell count (WCC) and C-reactive protein (CRP) were chosen as inflammatory markers. Findings were compared between the two groups.

RESULTS

The study population consisted of 125 patients, of whom 26 (20.8 per cent) had HIV infection. Clinical manifestations did not differ statistically, and there was no difference in the incidence of simple or complicated appendicitis between the two groups. The mean CRP level was significantly higher in HIV-infected patients (194.9 mg/l versus 138.9 mg/l in HIV-uninfected patients; P = 0.049), and mean WCC (x109/L) was significantly lower (11.07 versus 14.17×109/l respectively; P = 0.010).

CONCLUSION

Clinical manifestations and pathology did not differ between HIV-infected and HIV-uninfected patients with appendicitis, except that the WCC response was significantly attenuated and CRP levels were generally higher in the presence of HIV infection.

Correlation between thyroid ultrasound and histology in patients with indeterminate cytology results: a local experience

BACKGROUND

Thyroid nodules are common. Most patients with indeterminate fine needle aspiration cytology (FNAC) results are subjected to thyroidectomy for fear of malignancy. However, only 20-30% of these cases are found to be malignant. The aim was to determine the value of thyroid ultrasound in diagnosing malignancy in patients with indeterminate fine needle aspiration cytology results in our practice. Fine needle aspiration was performed after ultrasound, thereby preventing architectural distortion of the nodule and to ensure that the most suspicious nodule was biopsied.

METHODS

A retrospective review of records of patients who presented to two University of Pretoria academic hospitals, in South Africa, from 2001 to 2015 with nodular thyroid goitre was undertaken. Patients had a thyroid ultrasound scan, FNAC and had undergone thyroid surgery.

RESULTS

Records of 104 patients were retrospectively evaluated. Patients were predominantly female (93.3%). Histology report was available for 101 of the 104 patient records. Malignancy was identified in 23 (22.8%). The overall sensitivity and specificity of thyroid image reporting and data system (TIRADS) score in this study were 69.5% and 61.5% respectively. The TIRADS classification had high sensitivity amongst the 26 patients with indeterminate cytology, with sensitivity and specificity of 85.7% and 52.6% respectively, however it was not statistically significant (p = 0.28).

CONCLUSION

There was poor identification of malignancy with the use of ultrasound TIRADS classification in cases of indeterminate FNAC results, Bethesda III or IV, in our study. This is probably related to the diversity of ultrasonographers in our practice. It is recommended that there should be a dedicated thyroid ultrasonographer for a better and consistent TIRADS classification that surgeons can rely on for guiding surgical intervention.

Prevalence of Helicobacter pylori Infection in Patients with Squamous Cell Carcinoma of the Oesophagus. A Descriptive Case Series Study

INTRODUCTION

Helicobacter pylori is an important causative factor in gastric carcinogenesis; its role in extra-gastric gastrointestinal malignancies such as oesophageal cancer is controversial. H. pylori is thought to cause extensive gastric atrophy associated with squamous cell carcinoma of the oesophagus. We conducted a study to determine the prevalence of H. pylori infection in patients with squamous cell carcinoma of the oesophagus.

METHOD

We collected biopsies from the antrum and corpus of 59 patients with confirmed squamous cell carcinoma of the oesophagus, two from each area. These were then examined by an experienced histopathologist using methylene blue staining for the presence of H. pylori.

RESULTS

H. pylori was found in 30 (51 %) of the patients, a prevalence similar to that of the general population in South Africa. Five patients were found to have associated intestinal metaplasia, and all but two had chronic inflammation.

CONCLUSION

The prevalence of H. pylori in our patients with squamous cell carcinoma of the oesophagus is 51 %, similar to that previously reported in the general population.

Comparison of the therapeutic dose of warfarin in HIV-infected and HIV-uninfected patients: a study of clinical practice

BACKGROUND

People infected with HIV are prone to venous thrombosis. Treatment of thrombosis is primarily with warfarin. No studies have addressed the effects of HIV infection on warfarin dose. The aims of this study were to determine whether the therapeutic dose of warfarin and induction time to therapeutic dose in HIV-infected patients differ from that in HIV-uninfected patients.

METHODS

A prospective and retrospective descriptive study of induction time to therapeutic warfarin dose, as well as of ambulant therapeutic warfarin dose, was performed. HIV-infected and HIV-uninfected patients being treated after deep venous thrombosis with or without pulmonary embolism were compared. Sex and use of antiretroviral drugs (ARVs) were also compared in the groups.

RESULTS

234 patients were entered into the study. Induction time to therapeutic warfarin dose did not differ between the 2 groups. The mean therapeutic dose of warfarin was higher in the HIV-infected than the HIV-uninfected group: 6.06 vs 5.72 mg/day, but this was not statistically significant (p=0.29). There was no difference in therapeutic warfarin dose between ARV-naïve groups-HIV-uninfected and HIV-infected patients not on ARVs.

CONCLUSIONS

There appears to be little effect of HIV infection on warfarin dosing. Warfarin therapy should be administered conventionally in HIV-infected patients.

Motivators and deterrents to blood donation among Black South Africans: a qualitative analysis of focus group data

BACKGROUND AND OBJECTIVES

South Africa has a markedly skewed representation where the majority of blood (62%) is presently collected from an ethnically White minority. This study seeks to identify culturally specific factors affecting motivation of donors in South Africa.

MATERIALS AND METHODS

We performed a qualitative study to evaluate motivators and deterrents to blood donation among Black South Africans. A total of 13 focus groups, comprising a total of 97 Black South Africans, stratified by age and geographic location were conducted. Transcripts of the interviews were analysed using a coding framework by Bednall & Bove.

RESULTS

Participants made 463 unique comments about motivators focusing primarily on promotional communications (28%), incentives (20%) and prosocial motivation (16%). Participants made 376 comments about deterrents which focused primarily on fear (41%), negative attitudes (14%) and lack of knowledge (10%).

CONCLUSION

Although prosocial motivation (altruism) was the most frequently mentioned individual motivator, promotional communication elicited more overall comments by participants. As reported by many authors, fear and lack of awareness were strong deterrents, but scepticism engendered by perceived racial discrimination in blood collection were unique to the South African environment.

Inferior vena cava injuries: a case series and review of the South African experience

INTRODUCTION

Penetrating injury may involve the major vessels in the abdomen. Injury to the abdominal inferior vena cava (IVC) is uncommon and is usually caused by gunshot wounds. Mortality from IVC injuries is high and has changed little over time.

AIM

The aim of the study was to report a series of IVC injuries from an urban trauma unit and to compare this with reports from similar institutions.

METHOD

A retrospective review of penetrating abdominal injuries at Kalafong Hospital from 1993 to 2010 was performed. All cases of injury to the IVC were retrieved and the following data recorded: patient demographics, incident history, origin of referral, description of the IVC injury, associated injuries, operative management, hospital stay and outcome. The results were compared to those from similar institutions.

RESULTS

Twenty-seven patients with IVC injuries were treated. All were caused by gunshot wounds, and all had associated intra-abdominal injuries. The majority (56%) of injuries were infrarenal. The injury was managed most commonly by venorrhaphy and, when successful, all the patients survived. A third of patients with infrarenal injuries died, some after exploration of a stable peri-caval haematoma. Ten of the patients died (37%), half of them during surgery. These results are similar to those from similar institutions from earlier time periods.

CONCLUSIONS

This report concurs with other studies. IVC injury carries a high mortality rate and that this has not improved over several decades. Less aggressive management of some stable patients or stable injuries is proposed by the authors for possible improvement of the mortality rate.

Ectopic kidney presenting as appendix mass or abscess

Renal ectopia is very rare and its associated pyelonephritis can simulate an appendix mass/ abscess or colonic tumour which may result in needless surgical exploration, as illustrated by our experience with 3 cases reported in this article. Careful ultrasonography and urinalysis can obviate this confusion and save unnecessary operation.

Prognosis in posttraumatic acute renal failure is adversely influenced by hypotension and hyperkalaemia

OBJECTIVE

To see if it is possible to predict mortality in isolated post-traumatic acute renal failure.

DESIGN

Retrospective study 1984-1990 inclusive.

SETTING

Teaching hospital, South Africa.

SUBJECTS

Thirty-nine patients who developed isolated post-traumatic acute renal failure out of 106526 admissions for trauma.

INTERVENTIONS

Standard aggressive management of traumatic injury and acute renal failure.

MAIN OUTCOME MEASURE

Death.

RESULTS

Fifteen of the 39 patients who developed post-traumatic acute renal failure died (39%). Blunt trauma from assaults was a major cause of acute renal failure (16/39, 41%). Hypotension and hyperkalaemia were the two main predictors of death having a mortality of 63% and 52%, respectively.

CONCLUSION

Clinicians should be aware of the risks of hypotension and hyperkalaemia in injured patients. Preventive measures such as aggressive resuscitation and timely correction of serum electrolyte concentrations are essential in such patients.

Gunshot injuries of the liver: the Baragwanath experience

BACKGROUND

This study comprised 304 patients with gunshot injuries of the liver, many of which from high-velocity firearms. The purpose of this study is to evaluate our management policy in gunshot injuries of the liver in light of our recent wider experience.

METHODS

All grade I and II injuries and most grade III injuries were managed by simple operative measures, without postoperative mortality directly related to the liver trauma.

RESULTS

Grade III, IV, and V injuries had 8.5%, 52%, and 16% resectional debridement rates and 8.5%, 38%, and 84% perihepatic packing rates, respectively. In the resectional debridement group the postoperative mortality rate was 15% (half the deaths were directly caused by the hepatic injury). The postoperative mortality rate in the perihepatic packing group was 31.5% of which 45% of deaths were due to ongoing bleeding, 27.5% to sepsis, and 27.5% to associated trauma. The septic complications were less common when packs were removed early.

CONCLUSIONS

We suggest that resectional debridement and perihepatic packing should be liberally applied in the most severe grade III, most grade IV, and grade V gunshot injuries of the liver and that perihepatic packing should be removed as early as the physiologic derangements are corrected. Our experience with grade VI injuries is very limited, and their management should be studied in larger series.

Diagnostic difficulties in patients with a ruptured bladder

Isolated bladder rupture has an insidious presentation which results in delayed diagnosis and management. Forty-four patients, of mean age 33.3 years, were seen over a period of 7 years. There was a history of trauma in 33 patients, although this was minor in 20. Alcohol intoxication, head injury or paraplegia could have led to lack of sensation of the distending and subsequently injured bladder in 18 patients. The mean delay between an identifiable incident or presentation and diagnosis was 5.4 days. The mean admission or preoperative levels of blood urea and creatinine were raised to 19.6 mmol/l and 362 mumol/l respectively in those with a delayed diagnosis. The diagnosis was made by voiding cystourethrography in 36 patients and by laparotomy in eight. When blood urea and creatinine concentrations are increased in a patient with an ill-defined abdominal ailment and a history of trauma or drunkenness, ruptured bladder should be considered.

Selective surgical management in penetrating neck injuries

OBJECTIVE

To evaluate selective operative management in penetrating neck trauma.

DESIGN

A chart review.

SETTING

A university-affiliated hospital in Johannesburg, South Africa.

PATIENTS

All adults admitted to the hospital between January 1988 and June 1993 with a penetrating neck wound. Excluded were patients in whom there was no suspicion of an occult injury that might need further investigation. There were 755 patients in the study.

INTERVENTIONS

Immediate surgical exploration (group A, 613 patients) and observation with constant monitoring (group B, 142 patients).

MAIN OUTCOME MEASURES

Unnecessary explorations in group A and missed significant injuries in group B.

RESULTS

In group A there was a 3% incidence of unnecessary explorations, and 4.2% of the patients died. In group B there was a 9.1% incidence of missed injuries, and 2.8% of the patients died as a result of the delayed diagnosis. Overall the death rate was 4%.

CONCLUSION

Selective operative intervention for penetrating neck trauma results in fewer negative explorations and a death rate comparable to those of series that support mandatory neck exploration.

Pattern of diverticular disease among Africans

Diverticular disease of the colon was found to be a rare but emerging clinical problem among Urban Africans where 26 patients were recorded in this 5 year retrospective study, giving a hospital prevalence of 5 per 100,000 admissions. The pattern was different from that reported in Western communities in that, while diverticula were left sided in 77% of cases, 62% were right sided and 73% presented with haemorrhage. This confirms a reported experience among African Americans. We would like to postulate that it might be the pattern during a transition from traditional to Western diet.

Haemorrhage--the main presenting feature of diverticular disease of the colon in blacks

Haemorrhage is one of the less common presentations of diverticular disease. This retrospective 5-year study of 23 patients has identified it as the main presentation (74%) among South African blacks in whom the disease is uncommon, but emerging as a clinical problem. Women constituted a statistically significant majority of patients with bleeding (76%); this was in excess of their overall proportion among patients with diverticular disease (61%) (P = 0.018).

Surgical management of retroperitoneal necrotising fasciitis by planned repeat laparotomy and debridement

Mortality remains high in patients with necrotising fasciitis despite use of modern powerful antimicrobial drug therapy and advances in the care of the critically ill. This is particularly so in patients with intra-abdominal retroperitoneal lesions. While necrotising fasciitis of the integument has been well described, its retroperitoneal (extraperitoneal) location has not been highlighted. Planned repeated laparotomies and debridement have been used in 10 recent patients with only 2 deaths. The initiating incident was caesarean section in 3 patients; perineal sepsis, trauma or intra-uterine death in 2 patients each; and uterine instrumentation to induce early abortion in the remaining patient. All patients received empirical antimicrobial therapy, which was changed when microbial isolates and their sensitivity indicated. Mechanical ventilation support was given to 60% of the patients early on during the illness. All received nutritional supplementation either parenterally or enterally throughout their inhospital treatment. This report focuses on intra-abdominal extraperitoneal necrotising fasciitis and the use of planned repeated laparotomy and debridement in the treatment of retroperitoneal (extraperitoneal) necrotising fasciitis per se and we recommend it as an essential part of the management of this condition.

Oesophageal tuberculosis: a review of eleven cases

Tuberculous infection of the oesophagus is rare. This is confirmed by our present review of cases managed in our teaching hospitals over a period of 18 years which uncovered only 11 patients. The main presentation is that of dysphagia whose algorithm of investigation should seek to differentiate tuberculosis from carcinoma, the more common cause of this symptom. Of the 11 patients, 9 presented with dysphagia while 2 had haemorrhage; 7 had an abnormal plain chest radiograph, of whom 4 had a mediastinal mass lesion (3 were lymphadenopathy and one an abscess). All but one had an abnormal radio-contrast oesophagogram, including a mediastinal sinus in two and a traction diverticulum in another two. The mainstay of investigation was oesophagoscopy through which diagnostic biopsy material was obtained in half of the patients. In the other half diagnosis was by either biopsy of associated mediastinal (3) or cervical (1) lymph node masses or by acid fast bacilli positive sputum (1). The diagnosis was established post-mortem in one patient. Treatment was primarily non-operative with standard anti-tuberculosis drug therapy. Two patients underwent a diagnostic thoracotomy and one a drainage of mediastinal abscess together with resection and repair of oesophago-mediastinal sinus during the early part of the series. Outcome of management was very rewarding in 9 patients and death occurred in 2 patients, one of whom had his anti-tuberculosis drug therapy interrupted by severe hepatitis B virus infection. The other death occurred in a patient whose haemorrhage from an aorta-oesophageal fistula was not established ante-mortem. It is recommended that when biopsy material of the oesophagus is unobtainable or non-diagnostic in patients with dysphagia, especially with an abnormal chest radiograph or human immunodeficiency virus infection, effort should be made to obtain biopsy material from associated lymph nodes, even by thoracotomy if necessary, or culture of biopsy from the radiologically abnormal part oesophagus and sputum for mycobacteria, in order to establish the diagnosis of this rare but eminently treatable cause of dysphagia. Clinicians should be aware of tuberculosis of the oesophagus as a possible cause of haematemesis in patients with otherwise unexplained upper gastrointestinal haemorrhage.

Haemostasis by angiographic embolisation in exsanguinating haemorrhage from facial arteries. A report of 2 cases

Life-threatening exsanguinating haemorrhage from arteries of the face following trauma is uncommon. When it occurs it is often located in the relatively inaccessible parts of the vessels and requires deep face or neck exploration and ligation of the main feeding vessel. The procedure requires expert head and neck vascular surgery performed under general anaesthesia, which is often not suitable in these haemodynamically unstable patients. In addition, surgery is often rendered more difficult by the associated post-traumatic swelling and disfigurement. Because of these considerations, angiographic embolisation of the bleeding vessels was performed as an alternative to surgical exploration. This report illustrates its use in achieving haemostasis in 2 patients.

Surgical management of mycotic aneurysms

Mycotic aneurysms not associated with trauma or atherosclerosis are uncommon. Their clinical presentation is insidious and lacks definite diagnostic criteria. This retrospective study of 14 patients treated over a period of 9 years confirms this, and shows that half are associated with a predisposing infected focus and that the main presenting clinical feature is that of a painful mass (64%) which is often mistaken for some other diagnosis. The main extracranial, extrathoracic site of predilection was the iliofemoral segment (65%). The main diagnostic investigation was angiography, which was also used to uncover silent aneurysms elsewhere in the arterial tree. Urgent surgical treatment is mandatory since complications may occur at any time and these may include life-threatening bleeding. Two of our patients experienced life-threatening gastro-intestinal bleeding while in hospital. The mainstay of treatment was surgical resection and reconstruction using an autologous vein or artery if possible. The more serious complication of graft failure was encountered mainly in patients who underwent prosthetic graft repair. It is in this group that 2 of the 3 early postoperative deaths occurred, from graft thrombosis and mesenteric infarction. Overall, surgical repair was attended with good outcome (77%).

Surgical management of multiple limb gangrene following dehydration in children

Multiple limb gangrene and auto-amputation without arterial vascular occlusive disease is uncommon. Seven such paediatric patients were managed at King Edward VIII Hospital, Durban, during the 6-year period ending in 1989. The spectrum and degree of limb gangrene ranged from phalangeal necrosis to distal limb mummification affecting one or more limbs. The most affected child had gangrene and mummification of all limbs as well as gangrene of the ear lobes and the tip of the nose. The main associated factor was severe fluid loss--2 children had received herbal enemas, with resultant hypotension, hypoperfusion, hypernatraemia and acidosis, which, it is postulated, led to peripheral thrombosis and the ensuing gangrene. It is suggested that aggressive fluid therapy, including low molecular weight dextran and correction of the metabolic derangement, should form the main thrust of the therapeutic endeavour. Once gangrene is established, surgical debridement and rehabilitation is all that is possible. Using this procedure only 2 patients died in the acute resuscitation phase.

Interferon gamma induces synthesis of complement alternative pathway proteins by human endothelial cells in culture

Human umbilical vein endothelial cells grown in vitro under standard conditions contain a high level of mRNA specific for the complement regulatory factors H and I. An additional 1.8-kb mRNA encoding a truncated form of factor H is also present. IFN-gamma stimulation of the cells causes a 6-7 fold increase in both factor H mRNA species, and a greater than 10-fold increase in factor I mRNA. IL-1 and LPS slightly suppressed factor H mRNA, while TNF had no effect. mRNA for factor B is also detectable in IFN-gamma-stimulated cells, but messengers for C1q, C4bp, and CR3 beta chain were not found. Secretion of factor H protein was also stimulated by IFN-gamma. The presence of mRNA for factors H, B, and I, together with C3 secretion, demonstrated by others, suggests that endothelial cells can assemble the complete alternative complement pathway. Endothelial cell complement may be involved in leukocyte-endothelium interactions mediated by leukocyte C3 receptors.

Human macrophage activation. Modulation of mannosyl, fucosyl receptor activity in vitro by lymphokines, gamma and alpha interferons, and dexamethasone

We describe a sensitive assay to measure immune activation of human macrophages in cell culture. Freshly isolated blood monocytes from normal subjects lack the ability to endocytose and degrade mannosyl-terminated glycoconjugates via specific receptors, but acquired this activity after cultivation in autologous serum for approximately 3 d. Addition of specific antigen, purified protein derivative, or T cell mitogens to mononuclear cells prevented the appearance of macrophage mannosyl receptor activity and lymphokine, gamma-, and alpha-interferons selectively down-regulated receptor activity in monocyte-macrophage targets. The effects of antigen challenge and gamma-interferon on mannosyl receptors can be prevented by 10(-8) M dexamethasone. Dexamethasone also inhibited release of another macrophage activation marker, plasminogen activator, which was increased by both gamma- and alpha-interferons. These studies show that activation of human macrophages is regulated by opposing actions of lymphokines and glucocorticoids.