Time course and localization of nerve growth factor expression and sensory nerve growth during progression of knee osteoarthritis in rats

OBJECTIVES

Nerve growth factor (NGF) and sensory nerves are key factors in established osteoarthritis (OA) knee pain. We investigated the time course of NGF expression and sensory nerve growth across early and late stages of OA progression in rat knees.

DESIGN

Knee OA was induced by medial meniscectomy in rats. OA histopathology, NGF expression, and calcitonin gene-related peptide immunoreactive (CGRP-IR) nerves were quantified pre-surgery and post-surgery at weeks 1, 2, 4 and 6. Pain-related behavior was evaluated using dynamic weight distribution and mechanical sensitivity of the hind paw.

RESULTS

NGF expression in chondrocytes increased from week 1 and remained elevated until the advanced stage. In synovium, NGF expression increased only in early stages, whereas in osteochondral channels and bone marrow, NGF expression increased in the later stages of OA progression. CGRP-IR nerve density in suprapatellar pouch peaked at week 4 and decreased at week 6, whereas in osteochondral channels and bone marrow, CGRP-IR innervation increased through week 6. Percent ipsilateral weight-bearing decreased throughout the OA time course, whereas reduced paw withdrawal thresholds were observed only in later stages.

CONCLUSION

During progression of knee OA, time-dependent alterations of NGF expression and CGRP-IR sensory innervation are knee tissue specific. NGF expression increased in early stages and decreased in advanced stage in the synovium but continued to increase in osteochondral channels and bone marrow. Increases in CGRP- IR sensory innervation followed increases in NGF expression, implicating that NGF is a key driver of articular nerve growth associated with OA pain.

AB0201 INTAKE OF FISH RICH IN n-3 POLYUNSATURATED FATTY ACIDS IS ASSOCIATED WITH GOOD RESPONSE TO TREATMENT IN RHEUMATOID ARTHRITIS PATIENTS RECEIVING TARGETED THERAPIES

Background

The management of rheumatoid arthritis (RA) has been transformed by the use of molecular targeted therapies. Early treatment and treat-to-target approach leads to good clinical response and remission (responders), but not in all patients.

Environmental factors including diet contribute to the development, activity and severity of RA. Evidence from clinical trials suggested that dietary interventions, such as Mediterranean diet or supplementation with fish oil rich in n-3 polyunsaturated fatty acids (n-3 PUFA), have positive effects on RA. Japanese and Mediterranean diets are associated with longevity and characterized by high fish intake. Clinical studies have identified predictors of treatment response in individual RA patients, however, the influence of fish consumption on treatment response in RA patients treated with targeted therapies has not been elucidated.

Objectives

To assess whether fish consumption is associated with a good response to targeted therapies in RA patients with Japanese and Mediterranean dietary patterns.

Methods

The study is a collaborative international cross-sectional retrospective study enrolling patients with RA on treatment with biologics or JAK inhibitors attending to Hokkaido University Hospital, Japan or Hospital Virgen de las Nieves, Spain.

Enrolled patients were asked to complete a brief-type self-administered diet history questionnaire (BDHQ) and a detailed fish frequency questionnaire (DFFQ) referring to consumption frequency in the previous month. At study entry, alcohol consumption, tobacco habits, educational level and employment status were recorded and RA disease activity evaluated by qualified rheumatologists. Demographic, clinical/laboratory data were retrospectively extracted from the medical records.

By December 2021, 279 patients (Japan 217, Spain 62) returned the questionnaires. A preliminary analysis was carried out with the first 58 Japanese patients in which all clinical and laboratory data could be collected. A descriptive analysis was performed and the relative risks approximated by odds ratios.

Results

Fifty-eight Japanese RA patients, 45 females, median age at entry 66 yrs [IQR 54-73], median disease duration 11yrs [IQR 7-20] were included in this analysis. Fifty-three (93%) of patients were on biologic therapies and four (7%) on JAK inhibitors with a median treatment duration of 4.5 yrs [IQR 1-7]. Concomitant treatment with conventional DMARDS and glucocorticoids were reported in 69% and 48% of patients, respectively. Forty-two (72%) patients were responders to treatment defined as DASESR ≦3.2. Another systemic autoimmune disease, hypertension, diabetes mellitus, dyslipidemia or gout history were present in 29%, 29%, 9%, 33% and 10% of patients, respectively.

All patients had consumption of fish in the last month and an intake of n3-PUFA rich fish (fatty fish) was indicated by 82% (<1 time/week 34%, ≧ 1 time/week 48%).

The patients’ fatty and non-fatty fish intake scores were calculated with a mathematical formula based on the intake of each of the fish included in the DFFQ and number of responses. In the group of high fatty fish score patients (≧ 1 time/week) 94% were responders to treatment vs. 6% non-responders, [OR 8.75, CI [1.0-73.54, p= 0.022] while only 63% of patients in the high non-fatty fish score group respond to the treatment.

Conclusion

Fatty fish intake associated with a good response to treatment in patients receiving targeted therapies, suggesting that fish consumption may have some beneficial effects on RA treatment.

References

There is no reference.

Acknowledgements

Acknowledgements to Ms. Y. Ikea and S. Kumagai for their enriching support on the nutritional properties of fish. Supported by the Kakenhi C grant number 20K11597 from the Japan Society for the Promotion of Science.

Disclosure of Interests

None declared

AB0458 DISEASE ACTIVITY AT CONCEPTION PREDICTS LUPUS FLARE UP TO 2 YEARS AFTER BIRTH: A MULTICENTRE LONG TERM FOLLOW-UP STUDY

Background

Systemic lupus erythematosus (SLE) often affects women in their childbearing years, and pregnancy may affect SLE disease activity during pregnancy and post-partum (1,2). Limited data assessing the likelihood and characteristics of SLE activity in an extended time period post-partum which may be relevant as patients may wish further pregnancies exist.

Objectives

To assess predicting factors that might influence SLE disease activity in women in an extended follow-up period of 2 years after giving birth and clinical assessment every three months.

Methods

The study was design as an international retrospective, data-driven case collection study, enrolling 119 women with a first birth and with a strictly monitored follow-up period of 2 years.

Results

Table 1 shows pregnancy outcomes of all pregnancies. When considering disease manifestations, joint involvement was present in 80% of patients, acute cutaneous in 64%, haematological in 54%and renal in 41%; 75% of patients were positive for anti-dsDNA, 49% for anti-ENA and 37% for anti-Ro/SSA positive. The mean SLE disease activity index 2000(SLEDAI-2k) at diagnosis was 13.5±6.8 and at first birth was 2.8±4.4.

Table 1.

Pregnancy outcomes of all pregnancies and relative breastfeeding data

Pregnancy CharacteristicsAll (214)%OutcomesLive births16979Miscarriages3717.3Stillbirths83.7Maternal and Foetal ComplicationsPrematurity3918.2Pre-eclampsia2310.7HELLP syndrome41.9Placental Infarction125.6Breastfeeding (all pregnancies)Any breastfeeding (n, %)10964.5*Exclusive breastfeeding (n, %)8751.5*Breastfeeding (after first birth)Any breastfeeding (n, %)8773.1**Any breastfeeding duration (months) (m±sd)10.29±10.04Exclusive breastfeeding*** (n, %)6252.1**Exclusive breastfeeding*** duration (months) (m±sd)6.07±6

*Percentages are calculated considering viable babies (total= 169)

**Percentages are calculated considering first birth (total= 119)

***Exclusive breastfeeding was defined as feeding infants only breast milk

At follow-up, 51.3% of patients had at least one flare after a mean time after birth of 9±6.3 months(mean flare per patient 0.94±1.1). The most frequent flare manifestations were joint involvement(48%), followed by renal(33%), cutaneous(28%) and haematologic(20%).

Patients with remission of disease(SLEDAI-2K=0; no clinical or laboratory manifestations of SLE) at conception had significantly lower rates of flares than those not in remission (18/49–37% vs. 43/70–61%;p=0.008) (Figure 1).

Figure 1.

Flare proportion: Survival Curve based on remission status at conception of the patients included in the study.

Patients who experienced a flare during pregnancy (17 patients), when compared to those who did not, had higher rates of flares during follow-up (76% vs. 47%, respectively, p=0.019), lower time for first flare (4.4±2.3 months vs. 10.3±6.5, respectively, p<0.001), lower rate of remission of disease at conception (12% vs. 46%, respectively, p<0.001), lower rates of SLEDAI 2K at conception (5.9±5.6 vs. 2.3±4, respectively, p<0.001) and lower rates of exclusive breastfeeding (24% vs. 57%, respectively, p=0.009).

Remission of disease and flares during pregnancy remained significantly associated with the development of flares during follow-up after multivariate analysis.

Conclusion

Remission at conception can influence SLE disease positively, even at long-term. Planned pregnancy counseling is fundamental when managing SLE patients.

References

[1]Tincani A, Nalli C, Khizroeva J, Bitsadze V, Lojacono A, Andreoli L, et al. Autoimmune diseases and pregnancy. Best Pract Res Clin Endocrinol Metab 2019;33.

[2]Clowse MEB, Magder LS, Witter F, Petri M. The impact of increased lupus activity on obstetric outcomes. Arthritis Rheum 2005;52:514–521.

Disclosure of Interests

None declared

Contribution of nerves within osteochondral channels to osteoarthritis knee pain in humans and rats

OBJECTIVES

Subchondral bone may contribute to knee osteoarthritis (OA) pain. Nerve growth factor (NGF) can stimulate nerve growth through TrkA. We aimed to identify how sensory nerve growth at the osteochondral junction in human and rat knees associates with OA pain.

METHODS

Eleven symptomatic chondropathy cases were selected from people undergoing total knee replacement for OA. Twelve asymptomatic chondropathy cases who had not presented with knee pain were selected post-mortem. OA was induced in rat knees by meniscal transection (MNX) and sham-operated rats were used as controls. Twice-daily oral doses (30 mg/kg) of TrkA inhibitor (AR786) or vehicle were administered from before and up to 28 days after OA induction. Joints were analysed for macroscopic appearances of articular surfaces, OA histopathology and calcitonin gene-related peptide-immunoreactive (CGRP-IR) sensory nerves in medial tibial plateaux, and rats were assessed for pain behaviors.

RESULTS

The percentage of osteochondral channels containing CGRP-IR nerves in symptomatic chondropathy was higher than in asymptomatic chondropathy (difference: 2.5% [95% CI: 1.1-3.7]), and in MNX-than in sham-operated rat knees (difference: 7.8% [95%CI: 1.7-15.0]). Osteochondral CGRP-IR innervation was significantly associated with pain behavior in rats. Treatment with AR786 prevented the increase in CGRP-IR nerves in osteochondral channels and reduced pain behavior in MNX-operated rats. Structural OA was not significantly affected by AR786 treatment.

CONCLUSIONS

CGRP-IR sensory nerves within osteochondral channels are associated with pain in human and rat knee OA. Reduced pathological innervation of the osteochondral junction might contribute to analgesic effects of reduced NGF activity achieved by blocking TrkA.

Impact of medial versus lateral knee pain on deep tissue hyperalgesia and muscle strength

BACKGROUND

Accumulating evidence indicates that knee pain gives rise to sensory and motor alterations, however, whether different profile of knee pain causes different alterations has not been investigated. The purpose of this experimental study is to clarify characteristics of medial and lateral knee pain and its potential for modulating sensory and motor function in humans.

METHODS

Fourteen healthy men were included. Medial knee pain (MP) was induced by injection of hypertonic saline (0.5 mL) into the tibial insertion of the medial collateral ligament. For comparison, lateral knee pain (LP) was induced by injection of hypertonic saline identically into the iliotibial tract. Isotonic saline was injected contralaterally as control. Pain intensity was assessed on a continuous electronic visual analogue scale (VAS). Before, during and after the painful state, pressure pain thresholds from the knee (PPTs), maximal isometric muscle strength of the quadriceps and grip power were assessed bilaterally.

RESULTS

MP demonstrated significantly higher VAS scores than LP and compared with control. PPTs decreased on medial and lateral knee in MP but only on the lateral knee in LP. Quadriceps muscle strength and grip power reduced bilaterally in both models, however, MP caused significantly greater reduction of ipsilateral quadriceps strength compared with LP.

CONCLUSION

Medial knee pain has a greater impact on deep tissue hyperalgesia and reduction of the muscle strength compared with lateral knee pain. This is a novel finding that should be taken into consideration in a treatment strategy for painful knee patients.

SIGNIFICANCE

The experimental medial knee pain model demonstrated higher pain intensity, more localized pain distribution, widespread deep tissue hyperalgesia and more severe inhibition of muscle strength compared with the lateral knee pain model.

Platelet-dependent serum factor that stimulates the proliferation of epidermal cells in vitro

Agglutinated platelets are known to release a factor that stimulates the growth of arterial smooth muscle cells or dermal fibroblasts. The present study was designed to see the effect of this platelet factor on epidermal cells. The growth of cultured epidermal cells and dermal fibroblasts obtained from guinea pig ear skin was observed using 10% platelet-rich serum or platelet-poor serum in the culture medium. These sera were prepared from fresh human blood according to the method described by Ross. The cell growth was checked by counting the number of cells in culture or by the uptake of labeled thymidine by the cells. The platelet-rich serum significantly stimulated the growth of epidermal cells as well as fibroblasts as compared with the platelet-poor serum. This implies that platelet factor released after injury to cutaneous vessels in trauma or inflammation plays an important role in initiating proliferation of epidermal cells and dermal fibroblasts.

Repeated intra-articular injections of acidic saline produce long-lasting joint pain and widespread hyperalgesia

BACKGROUND

Synovial fluid in inflamed joint shows a drop in pH, which activates proton-gated ion channels in nociceptors. No studies have ever tried to develop and characterize acid-induced joint pain.

METHODS

Rats were injected intra-articularly with pH 4.0 acidic saline twice, 5 days apart. Pain-related behaviour tests including weight-bearing asymmetry, paw withdrawal threshold and knee compression threshold were conducted. To clarify the roles of proton-gated ion channels, rats were injected intra-articularly with selective antagonists for ASIC1a, ASIC3 and TRPV1 on day 5 (before the second injection) or on day 14. Underlying peripheral and central pain mechanisms were evaluated using joint histology, interleukin-1β concentrations in the synovium, single-fibre recording of the knee afferent and expression of phosphorylated cyclic adenosine monophosphate-responsive element-binding protein (p-CREB) in the spinal dorsal horn.

RESULTS

Repeated injections of acidic saline induced weight-bearing asymmetry, decrease in paw withdrawal threshold and knee compression threshold bilaterally, which lasted until day 28. Early administration of ASIC3 antagonist reduced the bilateral and long-lasting hyperalgesia. Neither articular degeneration nor synovial inflammation was observed. C-fibre of the knee afferent was activated by acidic saline, which was attenuated by pre-injection of ASIC3 antagonist. p-CREB expression was transiently up-regulated bilaterally on day 6, but not on day 14.

CONCLUSION

We developed and characterized a model of acid-induced long-lasting bilateral joint pain. Peripheral ASIC3 and spinal p-CREB played important roles for the development of hyperalgesia. This animal model gives insights into the mechanisms of joint pain, which is helpful in developing better pain treatments.

PET in infancy predicts long-term outcome during adolescence in cryptogenic West syndrome

BACKGROUND AND PURPOSE

Developmental and seizure outcomes in patients with cryptogenic West syndrome are variable. Our aim was to clarify the relationship between FDG-PET findings in infancy and long-term seizure and developmental outcome in cryptogenic West syndrome.

MATERIALS AND METHODS

From 1991 to 1999, we prospectively performed FDG-PET from the onset of cryptogenic West syndrome in 27 patients. PET was performed at onset and at 10 months of age. In 2012, we evaluated the educational status, psychomotor development, and seizure outcome in 23 of the 27 patients (13-22 years of age). The correlation between PET findings and outcome was evaluated.

RESULTS

At onset, PET showed hypometabolism in 13 patients (57%). The second PET after the initial treatment revealed cortical hypometabolism in 7 patients (30%). While hypometabolism at onset disappeared on the second PET in 9 patients, it was newly revealed in 3 patients on the second PET. In 2012, seven patients had persistent or recurrent seizures. Eight patients had intellectual impairment. The first PET did not correlate with seizure or developmental outcome. Five of 7 patients (71%) with hypometabolism seen on the second PET had persistent or recurrent seizures, while 14 of 16 (88%) patients with normal findings on the second PET were free of seizures. Five of 7 patients (71%) showing hypometabolism on the second PET had intellectual impairment. Thirteen of 16 (81%) patients with normal findings on the second PET showed normal intelligence. A significant correlation was found between the second PET and long-term seizure (P = .01) or developmental outcome (P = .03).

CONCLUSIONS

Cortical hypometabolism is not permanent; it changes with clinical symptoms. Hypometabolism after initial treatment predicts long-term seizures and poor developmental outcome.

Cause of death in renal transplant patients: a comparison between azathioprine and ciclosporin

The results of renal transplantation have improved due to advances in immunosuppression techniques of preservation, and pre- and postoperative treatments; however, both morbidity and mortality remain serious problems. To decrease the morbidity and mortality rates we analyzed the causes of death after renal transplantation in our hospital. Between 1972 and 1999, we performed 364 renal transplantations, 257 of which were living-related and 107, cadaveric. There were 178 patients given azathioprine and 186 given ciclosporin. The survival rate of the patients on ciclosporin therapy was much better than that of those on azathioprine therapy. Of the total 364 renal transplant patients, 59 (16.2%) died, and 28 (47.5%) of these 59 deaths occurred within 1 year after renal transplantation. The causes of death were infection in 19 (32.2%) patients, gastrointestinal diseases in 16 (27.1%), cardiovascular diseases in 11 (18.6%), cerebrovascular diseases in 6 (10.2%), suicide in 3 (5.1%), and other causes in 4 (6.8%). These findings reinforce that early diagnosis and treatment are essential to decrease the morbidity and mortality rates assoiated with renal transplantation.

Pyrrolo[2,3-d]pyrimidine thymidylate synthase inhibitors: design and synthesis of one-carbon bridge derivatives

A series of novel pyrrolo[2,3-d]pyrimidine derivatives was designed and synthesized as thymidylate synthase (TS) inhibitors. Molecular design was performed on the human TS complex model built on the basis of the reported structure of TS-deoxyuridinemonophosphate (dUMP)-CB3717 ternary complex. From a docking study, we expected that a one-carbon bridge between pyrrolo[2,3-d]pyrimidine and an aromatic ring was suitable. Moreover, we found that the bridge carbon could be replaced with an alkyl group to fill out the unoccupied space. Based on this design, we synthesized five pyrrolo[2,3-d]pyrimidine derivatives with one-carbon bridge and evaluated their TS inhibitory activities. All synthesized compounds inhibited TS more potently than compound 2 (LY231514), and the C8-ethyl analogue (7) showed a remarkable inhibitory activity against TS (IC50=0.017 microM).

Macrophage inflammatory protein-2 induced by TNF-alpha plays a pivotal role in concanavalin A-induced liver injury in mice

BACKGROUND/AIMS

Macrophage inflammatory protein-2 (MIP-2), one of the CXC chemokines, is involved in the recruitment of neutrophils in several tissue injuries. In this study, we investigated the role of MIP-2 in concanavalin A (Con A)-induced liver injury in mice.

METHODS

Liver injury was induced by intravenous injection of Con A (15 mg/kg) and plasma alanine aminotransferase (ALT), MIP-2 levels were determined and histological assessment of the liver was performed. Anti-mouse MIP-2 antibody was intravenously administered 30 min before Con A injection.

RESULTS

The plasma ALT level significantly elevated and reached a maximum at 8 h after Con A injection. The plasma MIP-2 level was also elevated and reached a peak value at 2 h after Con A injection. The elevated ALT level by Con A injection was significantly inhibited by the MIP-2 antibody. The elevated plasma MIP-2 level after Con A injection was significantly reduced by the tumor necrosis factor alpha (TNF-alpha) antibody, and MIP-2 was induced in plasma after recombinant TNF-alpha injection. Hepatic necrosis and infiltration of neutrophils were observed after Con A injection, and these histological changes were attenuated by the MIP-2 antibody.

CONCLUSIONS

These findings suggest that Con A induces TNF-alpha release, and this TNF-alpha stimulates MIP-2 induction, at least partially contributing to the liver injury mediated through the recruitment of neutrophils.

Free radical-mediated tolbutamide desensitization of K+ATP channels in rat pancreatic beta-cells

To study the effects of hydroxyl radicals on the sensitivity of the ATP-sensitive K+ (K+ ATP) channel to tolbutamide, we used patch clamp and microfluorometric techniques in pancreatic beta-cells isolated from rats. cell-attached membrane patches, exposure of the cells to 0.3 mM H2O2 increased the probability of opening of K+ATP channels in the presence of 2.8 mM glucose. Tolbutamide dose-dependently inhibited the K+ATP channel with half-maximal inhibition (IC50) at 0.8 microM before and immediately after exposure to H2O2. After prolonged exposure (>20 min) to H2O2, the IC50 was increased to 15 microM. The presence of both ATP and ADP at concentrations ranging from 0.01 to 0.1 mM in the inside-out bath solution significantly enhanced the inhibition of the channels by 10 microM tolbutamide. Addition of 0.3 mM H2O2 induced a transient minute increase in the cytoplasmic Ca2+ concentration ([Ca2+]i) within 10 min, followed by a sustained pronounced increase in [Ca2]i. After more than 20 min of exposure of cells to 0.3mM H2O2, [Ca2]i was increased to above 2 microM. Treatment of the cytoplasmic face of inside-out membrane patches with 1 microM Ca2+ attenuated the tolbutamide-sensitivity of the K+ATP channel, but not the ATP-sensitivity of the channel. These findings indicate that H2O2 reduces tolbutamide sensitivity by inducing a sustained increase in [Ca2+]i.

[Evaluation and improvement of medical and nursing service and caregiving for the elderly using MDS. 3. Revised recording system of diagnoses and symptoms suitable for use in Japan]

Diagnoses and symptoms are recorded by physicians in the chapter E of the Minimum Data Set (MDS), if they are relevant to disabilities of activities of daily living, cognition, behavior, medical treatments or risk of death. We improved the chapter so that it is suited to disease patterns in Japan in a format useful not only for nursing and ADL care but for medical treatment in our practice. In E1, diseases directly underlying the current disability states were recorded in the international classification of Disease, 9th Revision (ICD9). In 24, 670, 195, and 45 patients respectively, there were 0, 1, 2, and 3 separate recorded diseases. A Total of 63 ICD9 codes were observed, but only four codes; 290, 332, 431, and 434, were underlying diseases for 3% or more patients. These codes included mostly ischemic and degenerative disease of the brain.

Limitations in the medical treatment of cryptogenic or symptomatic localization-related epilepsies of childhood onset

We retrospectively examined 169 patients who had cryptogenic or symptomatic localization-related epilepsies (LRE) and were followed-up for more than 5 years. The probability of seizure control was 0.13 during the first year of treatment, 0.25 during the first 5 years, and 0.09 during the second and third 5 years. No patients who continued to have intractable seizures for 15 years became free of seizures. The onset of LRE at the age of 3 years or less, seizure cluster, mesial temporal sclerosis (MTS), and temporal lobe epilepsy (TLE) were significantly associated with a poor seizure control. If an antiepileptic drug (AED) failed to control seizures, probability of seizure control by the next drug was low, in particular in patients in whom more than 4 AEDs have already been tried, and seizure control could not be expected after a trial of 6 AEDs. A tentative indication of epilepsy surgery for LRE of childhood onset may be 5 years of poor seizure control and/or failure of four AEDs.

[Evaluation and improvement of medical and nursing service and caregiving for the elderly using MDS. 2. Diagnosis and symptoms, especially diseases causing care-requiring conditions]

Diagnoses recorded in the chapter E of Minimum Data Set (MDS) were analyzed in patients requiring care admitted in a geriatric hospital in Sapporo, Japan. They were classified as: A-diseases causing care-requiring conditions, B-their symptoms, and C-coexisting diseases requiring no care. Orthopedic diseases were not analyzed because they were not adequately recorded in MDS system. Class A diagnoses varied, but only five diagnoses were responsible for 3% or more of the total patients who required care. They were 1) Alzheimer's disease (AD), 2) Parkinson's disease, 3) dementia other than AD without neurological symptoms, 4) dementia other than AD with sequelae of stroke, and 5) sequelae of stroke without dementia. These diagnoses pooled represented over 90% of all patients. "Diagnoses and symptoms" in MDS were useful to 1) describe medical problems briefly in a predetermined format, 2) evaluate urgent or unstable conditions separately from stable diagnoses and symptoms, and 3) use common information by various professions, but have difficulties because 1) preselected diagnoses were few and unsuited to practices in Japan, 2) it is impossible to record a previous disease in the past that initiated the process leading to the present disabilities, and 3) it is also impossible to record the severities of the diseases and symptoms.