Rapid Biphasic Decay of Intact and Defective HIV DNA Reservoir During Acute Treated HIV Disease

Antiretroviral therapy (ART) is not a cure. Upon ART cessation, virus rapidly rebounds from latently-infected cells ("the HIV reservoir"). The reservoir is largely stabilized at the time of ART initiation and then decays slowly. Here, leveraging >500 longitudinal samples from 67 people with HIV (PWH) treated during acute infection, we developed a novel mathematical model to predict reservoir decay using the intact proviral DNA assay (IPDA) from peripheral CD4+ T cells. Nonlinear generalized additive models adjusted for initial CD4+ T count, pre-ART viral load, and timing of ART initiation demonstrated rapid biphasic decay of intact DNA (week 0-5: t1/2 ~0.71 months; week 5-24: t1/2 ~3.9 months) that extended out to 1 year of ART, with similar trends for defective DNA. Predicted reservoir decay were faster for participants individuals with earlier timing of ART initiation, higher initial CD4+ T cell count, and lower pre-ART viral load. These estimates are ~5-fold faster than prior reservoir decay estimates among chronic-treated PWH. Thus, these data add to our limited understanding of host viral control at the earliest stages of HIV reservoir stabilization, potentially informing future HIV cure efforts aimed at diverse, global population of PWH initiating ART at varying stages of disease.

Intracranial haemorrhage in children with inherited bleeding disorders in the UK 2003-2015: A national cohort study

INTRODUCTION

Intracranial haemorrhage in children with inherited bleeding disorders is a potentially life-threatening complication and presents a significant therapeutic challenge.

AIM

To define the characteristics, management and outcomes of intracranial haemorrhage presenting in UK children ≤16 years of age with inherited bleeding disorders from 2003 to 2015.

METHOD

Retrospective analysis of children treated at UK haemophilia centres.

RESULTS

Of 66 children presenting with Intracranial haemorrhage (ICH), 82% had haemophilia A or B, 3% VWD and 15% a rare IBD. The IBD was a severe phenotype in 91%. The rates of ICH were 6.4 and 4.2 per 1000 patient years for haemophilia A and B, respectively. Median age at presentation was 4 months (33% neonates; 91% children <2 years of age). In neonates, delivery was spontaneous vaginal (SV) in 11, instrumental in 6, caesarean in 4 and unknown in 1. In children with haemophilia, the risk of ICH after instrumental delivery was 10.6 times greater than after SV delivery. Trauma was more common in children >2 years (67%) than in children 1 month to 2 years (18%; P = .027). Prior to ICH, only 4.5% of children were on prophylaxis. 6% of haemophiliacs had an inhibitor. The median duration of initial replacement therapy was 15 days. Mortality was 13.5%. Neurological sequelae occurred in 39% of survivors, being more common following intracerebral bleeding. In haemophilia survivors, 52% subsequently developed a FVIII inhibitor.

CONCLUSION

Intracranial haemorrhage occurs most frequently in children with severe IBDs, during the first 2 years of life and in children not receiving prophylaxis. Intracranial haemorrhage often occurs without documented trauma.

Cutaneous involvement of disseminated adenovirus infection in an allogeneic stem cell transplant recipient

Infection by human adenoviruses can lead to significant morbidity and mortality in immunocompromised hosts, such as allogeneic stem cell transplant (SCT) recipients, with limited effective treatment options. Specific cutaneous manifestations of disseminated adenovirus infection are not well described. We report a woman in her twenties who received an allogeneic T-cell-depleted peripheral blood SCT for the treatment of severe aplastic anaemia and, 5 months post-transplant, was hospitalized for severe systemic adenovirus infection with progressive involvement of the colon, liver and lungs. Despite therapy with intravenous cidofovir, oral brincidofovir and intravenous immunoglobulin, she had progression of adenoviraemia and dissemination of adenoviral disease. The patient developed a progressive rash characterized by keratotic papules that began on the palms and soles and spread to the entire body. Histopathological examination of skin biopsies of individual skin lesions from the palm and abdomen showed focal acantholytic dyskeratosis and keratinocytes with hyperchromatic nuclei. Several keratinocyte nuclei were immunoreactive for adenovirus. The patient was further treated with ribavirin and adenovirus-specific cytotoxic T lymphocytes but experienced multisystem progression of adenovirus infection culminating in death.

In healthy subjects, the sitting position can be used to validate the postural effects induced by wearing a lumbar lordosis brace

AIM OF THE STUDY

To assess the validity of the sitting position when testing lumbar braces for the maintenance of lordosis.

PATIENTS AND METHODS

Twelve young adult subjects participated in the experiment, in which they were seated on force platform. The four experimental conditions (with or without a brace and with or without enforced lordosis) were chosen in order to distinguish between the roles played by lordosis and the brace, respectively. The trajectories of the centre of pressure (CP) were analyzed and compared, in order to assess postural orientation and stabilisation processes.

RESULTS

Although no effect was seen in terms of orientation, our data showed that use of a lumbar brace led to a notable reduction in CP displacement along the mediolateral and anteroposterior axes. Lordosis barely affected postural performance and only an increase in the mean CP velocity was observed. Lastly, an analysis of variance failed to reveal an interaction between the "lordosis" and "brace" factors.

CONCLUSION

A lumbar brace (in the absence or presence of lordosis) helps subjects to improve their sitting performance. In contrast to previous studies based on the standing posture, the fact that significant differences were found as a function of brace wear emphasises the discriminant power of the sitting position. This task should therefore be applied more widely in the development of more appropriate, validated equipment for lower back pain sufferers.

Rituximab and immune tolerance in severe hemophilia A: a consecutive national cohort

SUMMARY BACKGROUND AND OBJECTIVES: he management of patients with severe hemophilia A and inhibitors to factor VIII (FVIII) resistant to standard immune tolerance is challenging. There have been recent case reports of the successful use of rituximab in up to 57% of patients as part of rescue immune tolerance regimens. Because case reports and small series are prone to the potential bias of reporting good outcomes and relatively short follow up, a consecutive cohort of all patients treated in the UK with prolonged follow up was analyzed.

METHODS

A national survey of all Comprehensive Care Haemophilia Center in the UK.

RESULTS

A total of 15 patients were reported of whom six (40%) achieved a negative inhibitor titer by Bethesda assay. Durable responses were unusual, observed in only 14% of cases. Clinically significant responses with either a negative inhibitor or an inhibitor titer < 5 BU mL(-1) and no spontaneous bleeding with FVIII replacement were observed in seven (47%) cases. Concomitant use of FVIII appeared to be important. Of the 12 patients treated with rituximab and FVIII, six (50%) achieved a negative inhibitor titer and seven (58%) had a clinically beneficial response. None of the three patients treated without FVIII responded.

CONCLUSIONS

These data suggest that the use of rituximab combined with FVIII is a potentially useful treatment for patients with inhibitors resistant to standard immune tolerance, although sustained inhibitor eradication is uncommon.

Stem cell transplantation for children with Glanzmann thrombasthenia

Glanzmann thrombasthenia (GT) is a rare autosomal recessive platelet function disorder. Stem cell transplantation (SCT) is curative, but it is only indicated in selected patients with a severe clinical phenotype or who develop anti-platelet antibodies. SCT have previously been limited to full intensity myeloablative conditioning regimens. This study details the successful outcome of SCT in five consecutive patients with GT, three of whom received reduced intensity conditioning (RIC) with stem cells from non-sibling donors. This is the first time RIC SCT has been reported in GT, and offers the possibility of curative therapy with reduced late effects.

Intranasal desmopressin (OctimTM): a safe and efficacious treatment option for children with bleeding disorders

Desmopressin (1-deamino-8-D-arginine vasopressin (DDAVP)) has been shown to be an effective treatment option when administered both intravenously [1,2] and subcutaneously [3] to children with inherited bleeding disorders. We demonstrate here, both the efficacy and acceptability of a new intranasal DDAVP preparation, providing a cost effective treatment with good outcomes for children with bleed disorders.

Immune tolerance in children with factors VIII and IX inhibitors: a single centre experience

Alloimmune FVIII and FIX inhibitors are the most serious complication of haemophilia in the postviral contamination era and their optimal management remains controversial. We present 15 boys with severe haemophilia (14 with haemophilia A and 1 with haemophilia B) who have received immune tolerance at our centre over a 9-year period. Twelve of them (80%) were successfully tolerized with varying dose intensities, but three of them (including the boy with haemophilia B) failed tolerization. The factors, which were associated with successful tolerance in our group, were a low maximum inhibitor titre and a short interval between diagnosis of the inhibitor and the start of immune tolerance. The time taken to achieve immune tolerance varied from 1 to 27 months and none of the inhibitors have recurred. Two of the three boys who failed immune tolerance had had their inhibitor for 72 and 69 months, respectively before tolerance was attempted.

Subcutaneous administration of protein C concentrate

Children born with severe homozygous protein C deficiency do not survive beyond the neonatal period unless they receive protein C replacement. Protein C concentrate (Baxter Biosciences, Vienna) is usually given intravenously via a central venous catheter The authors describe 2 children in whom protein C concentrate was successfully administered by subcutaneous infusion after they had had recurrent central line infections. Alternate daily doses of 250-350 IU/kg resulted in trough protein C levels of > 25 IU/dL. In the follow-up period of 1-2 years neither child has had a thrombotic episode or purpuric skin lesions, and infusions are managed in the home by their parents.

Infection of Acanthamoeba polyphaga with Simkania negevensis and S. negevensis survival within amoebal cysts

Simkania negevensis, a novel microorganism belonging to the family Simkaniaceae in the order Chlamydiales, has an intracellular developmental cycle during which two morphological entities, elementary bodies (EB) and reticulate bodies (RB), are seen by electron microscopy. Rates of seropositivity to the organism are high in certain population groups, and S. negevensis has been associated with respiratory illness in humans. This study reports for the first time the ability of S. negevensis to survive and grow inside Acanthamoeba polyphaga in addition to its known ability to grow in cell cultures of human or simian origin. Infectivity of S. negevensis and growth in amoebae were monitored by immunoperoxidase assays. Long-term persistence and exponential growth of S. negevensis in amoebal trophozoites were demonstrated by infectivity assays and by electron microscopy. EB and dividing RB of S. negevensis were observed within inclusion bodies inside A. polyphaga. When S. negevensis-infected A. polyphaga amoebae were exposed to adverse conditions resulting in encystation of the amoebae, several possible outcomes were observed: cysts containing both normal amoebic cytoplasm and S. negevensis; cysts in which S. negevensis cells were relegated to the space between cyst walls; and cysts containing S. negevensis, but apparently lacking amoebal cytoplasm. S. negevensis within dried amoebal cysts was capable of long-term survival. The possibility that amoebae may have a role in natural transmission of S. negevensis needs to be investigated.

L-platelet activating factor induces changes on renal vascular resistance, vascular reactivity, and renin release in the isolated perfused rat kidney

Rat kidneys were isolated and perfused with a modified Krebs-Henseleit buffer containing 4% albumin. Perfusate recirculated except during L-platelet activating factor (L-PAF), angiotensin II (ang II), and norepinephrine (NE) infusions. L-PAF caused a dose-dependent decrease in renovascular resistance (RVR): -6 +/- 3% at 10(-9)M, -12 +/- 6% at 10(-8)M, -18 +/- 3% at 10(-7) and -20 +/- 7% at 10(-6)M. L-PAF increased immunoreactive PGE (iPGE) and thromboxane (iTXB) release into the venous effluent from 2.4 +/- 0.2 to 3.9 +/- 0.4 ng/min (p less than 0.05) and from 2.1 +/- 0.4 to 3.5 +/- 0.5 ng/min (p less than 0.05), respectively. Vasodilation by L-PAF (10(-7) M) in the presence of indomethacin (INDO) (5 microM) was enhanced compared to the non-INDO response (RVR change: L-PAF = -18 +/- 3% vs. L-PAF = -26 +/- 3%; p less than 0.05). As a control for specificity, the was infused at 10(-9) M, 10(-8) M, and 10(-7) M. None of these concentrations changed renal vascular resistance. To study the vascular receptor responsible for L-PAF-induced vasodilation, dose-response curves to NE and ang II were established with and without L-PAF (10(-7) M). The NE dose-response curve was unchanged by L-PAF, whereas the ang II dose-response curve was shifted to the right by one order of magnitude. In kidneys pretreated with INDO (5 microM), the L-PAF-induced shift of the ang II dose-response relation was increased to 2-3 orders of magnitude.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased pulmonary vascular responsiveness in rats raised on an essential fatty acid deficient diet

Leukotriene C4 is produced during hypoxic pulmonary vasoconstriction and leukotriene inhibitors preferentially inhibit the hypoxic pressor response in rats. If lipoxygenase products are important in hypoxic vasoconstriction, then an animal deficient in arachidonic acid should have a blunted hypoxic pressor response. We investigated if vascular responsiveness was decreased in vascular rings and isolated perfused lungs from rats raised on an essential fatty acid deficient diet (EFAD) compared to rats raised on a normal diet. Rats raised on the EFAD diet had decreased esterified plasma arachidonic acid and increased 5-, 8-, 11-eicosatrienoic acid compared to rats raised on the normal diet (control). Compared to the time matched responses in control isolated perfused lungs the pressor responses to angiotensin II and alveolar hypoxia were blunted in lungs from the arachidonate deficient rats. This decreased pulmonary vascular responsiveness was not affected by the addition of indomethacin or arachidonic acid to the lung perfusate. Similarly, the pulmonary artery rings from arachidonate deficient rats demonstrated decreased reactivity to norepinephrine compared to rings from control rats. In contrast, the tension increases to norepinephrine were greater in aortic rings from the arachidonate deficient rats compared to control. Stimulated lung tissue from the arachidonate deficient animals produced less slow reacting substance and platelet activating factor like material but the same amount of 6-keto-PGF1 alpha and TXB2 compared to control lungs. Thus there is an association between altered vascular responsiveness and impairment of stimulated production of slow reacting substance and platelet activating factor like material in rats raised on an EFAD diet.

Diethylcarbamazine inhibits acute and chronic hypoxic pulmonary hypertension in awake rats

Leukotriene inhibitors preferentially inhibit the acute pressor response to hypoxia in isolated rat lungs. If leukotrienes are important in hypoxic pulmonary vasoconstriction, then inhibition of their synthesis could prevent the development of chronic hypoxic pulmonary hypertension. We found that diethylcarbamazine (DEC), a leukotriene synthesis blocker, reversibly inhibited acute hypoxic pulmonary vasoconstriction in the awake rat. Rats exposed to chronic hypobaric hypoxia showed pulmonary hypertension and the production of a slow-reacting substance compared with low altitude control rats. The higher of 2 doses of DEC blocked the pulmonary hypertension and the production of slow-reacting substance in all of the hypoxic rats treated. The lower dose of DEC attenuated the pulmonary hypertension in only some of the rats. Changes in weight gain, hematocrit, or generation of prostacyclin did not explain the prevention of the pulmonary hypertension by DEC. We conclude that diethylcarbamazine inhibits acute and chronic pulmonary hypertension in the intact rat.

Leukotriene C4 production during hypoxic pulmonary vasoconstriction in isolated rat lungs

Leukotriene inhibitors preferentially inhibit hypoxic pulmonary vasoconstriction in isolated rat lungs. If lipoxygenase products are involved in the hypoxic pressor response they might be produced during acute alveolar hypoxia and a leukotriene inhibitor should block both the vasoconstriction and leukotriene production that occurs in response to hypoxia. We investigated in isolated blood perfused rat lungs whether leukotriene C4 (LTC4) could be recovered from whole lung lavage fluid during ongoing hypoxic vasoconstriction. Lung lavage from individual rats had slow reacting substance (SRS)-like myotropic activity by guinea pig ileum bioassay. Pooled lavage (10 lungs) as analyzed by reverse phase high performance liquid chromatography had an ultraviolet absorbing component at the retention time for LTC4. At radioimmunoassay, and SRS myotropic activity by bioassay. LTC4 was not found during normoxic ventilation, during normoxic ventilation after a hypoxic pressor response, or during vasoconstriction elicited by KCl. Diethylcarbamazine citrate, a leukotriene synthesis blocker, concomitantly inhibited the hypoxic vasoconstriction and LTC4 production. Thus 5-lipoxygenase products may play a role in the sequence of events leading to hypoxic pulmonary vasoconstriction.

Leukotriene E4 causes pulmonary vasoconstriction, not inhibited by meclofenamate

Leukotriene E4 (LTE4) appears to be a rather stable product of the lipoxygenase pathway. Its action in the pulmonary circulation is unknown. Therefore we investigated its effect on the circulation of isolated rat lungs perfused with a cell- and plasma-free solution. Synthetic LTE4 in doses from .15 micrograms to 5 micrograms/.25 ml .9% NaCl injected as a bolus in the pulmonary artery during normoxia caused a fast, transient perfusion pressure increase within seconds. This was followed by a slow rise in baseline perfusion pressure (normoxia) over 25 min. In addition, 5 micrograms LTE4 caused edematogenic lung damage. Injection of 1.5 micrograms LTE4 during hypoxic vasoconstriction caused fast, transient pressure rises, similar to normoxic conditions. 6-keto-PGF1 alpha and TXB2 were measured in the lung effluent before and after LTE4 injection. Neither 6-keto-PGF1 alpha nor TXB2 production changed after LTE4 injection. Meclofenamate (.5 micrograms/ml) increased the fast, transient and the slow, sustained pressure rise. We conclude that LTE4 caused direct pulmonary vasoconstriction unrelated to cyclooxygenase products.

The treatment of osteoarthritis with unconstrained and constrained knee prostheses

The first cases of knee prosthesis implantation at the orthopaedic department of the Freiburg university hospital are discussed. Surgery was indicated by advanced osteoarthritis which showed no improvement under conservative treatment. Indications concerning the choice of knee joint replacement with unconstrained or constrained prostheses are also discussed. Considerations of these indications as well as operative technique and consequent functional treatment usually produced good results. Follow up studies show equally good results for the GSB-total knee endoprosthesis (constrained) as for the surface type prosthesis (unconstrained).